Clojure android activity?
Is there still any activity in the clojure-android space? The clojure-android mail list is largely inactive, seems like the developers of lein-droid haven't done anything in months (1.7.0-r4 is still used in the templates), and the numerous references If ind for an android-clojure web site are all dead. That said, things do seem to mostly work for stock android. But accessing API's for android wear seems problematical (see https://github.com/clojure-android/lein-droid/issues/162 for my bug report). -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: Build tool for mixed Clojure/Java projects
On Tue, 12 Jul 2011 22:21:39 -0400 Ken Wesson kwess...@gmail.com wrote: Which means it's not really case 4 at all. Well, it's very clearly not cases 1, 2 or 3. No, it's case zero: standard multi-developer, multi-computer, single canonical master copy on one computer/cluster somewhere. The thing cases 1 through 4 were *alternatives* to. Technically true, but meaningless. The master gets tens of zillions of submissions Completely and totally wrong. Linus developed the model used by the Linux kernel specifically to avoid having some master copy on a central server with tens of zillions of submissions. He wrote a SCM that allowed the distributed, ad-hoc model to work without such a central server. All because his experience with the kernel up to that point was that he had reached the scalability limits of your case zero model. And now you're claiming it's a central server model in order to justify your erroneous assumption that having a repository implies having a server? I'm not sure whether that's more funny or pathetic. mike -- Mike Meyer m...@mired.org http://www.mired.org/ Independent Software developer/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Build tool for mixed Clojure/Java projects
On Mon, 11 Jul 2011 20:49:01 -0400 Ken Wesson kwess...@gmail.com wrote: On Mon, Jul 11, 2011 at 7:39 PM, Mike Meyer m...@mired.org wrote: On Mon, 11 Jul 2011 07:51:33 -0400 Ken Wesson kwess...@gmail.com wrote: On Sun, Jul 10, 2011 at 2:01 AM, mike.w.me...@gmail.com m...@mired.org wrote: [snip most of post whose sole purpose seems to be to gainsay anything I write] Because in that article, you were (unusual for you) way off base. As you say, it would be unusual for me if that were the case -- good reason to suspect that perhaps I wasn't, but rather was misinterpreted, or something. You write clearly enough that misinterpretation isn't likely. You were simply making false statements. SQL doesn't have a position anything like HTTP GET/POST syntax. Sure it does. Queries are bundled into a wire protocol and sent over the network in pretty much every system I've seen that used a database. You have the web server over *here*, and it is visible to the internet because the gateway forwards port 80 to it *here*; it talks over the LAN to the DBMS over *here* to run various queries and build a page to serve ... HTTP's GET/POST syntax is a wire protocol. HTTP is a wire protocol. The syntax of GET/POST requests is carried on that protocol (as are HTML files and other files sent back to the client) but is not the protocol itself. Once you it, you can write code to talk to a server, and get a response. Not if all you know is GET /index.html. You need to speak HTTP and then send that. If all you know is GET /index.html, then you don't know the syntax of the HTTP GET statement. The terminator - a pair of line endings - is part of the syntax. If you send that string and the terminator to an HTTP server, it should send back the contents of index.html. If you know SQL, you can't use a database *at all*. You have to know an API for the database in question Just as you need to know HTTP and not just GET /index.html. The difference here is that the databases haven't all settled on one embedding, analogous to HTTP, for the SQL requests, but all the vendors use their own different one. Sorry, but GET /index.html *is* HTTP. Oh, it's not all of it, by any means - but it's enough to talk to a server. A much closer analogy would be that SQL is like the URL syntax in the HTTP GET/POST request. Knowing the URL isn't enough to talk to a web server. You have to know the wire protocol, or the API for a library that implements it for you. Last time I looked, there wasn't a standard wire protocol for SQL servers. Which doesn't change much of anything. There's HTTP 1.0 and HTTP 1.1 for web servers for that matter, though mostly you can ignore the differences and, indeed, these days HTTP 1.0 as a whole. It's not hard to imagine a world where a non-HTTP protocol became a rival to HTTP, either -- for instance, one with built-in support for mirroring of static content instead of having to fudge around with things like Akamai for that, perhaps even one where individual browsers made parts of their caches (not https stuff, though, obviously, or form contents) available automatically as alternative sources to take some of the load off central servers and possibly even maintain some availability when they were down. If that were to happen, would the things that interpret GET requests suddenly stop qualifying for being considered to be servers? Only if they also stopped listening for requests on something like a socket. Which was your objection to running a repository: you think it means you have to have something listening on a socket. This isn't the case. In particular, it isn't the case for the maven repository that was being recommended as a solution to the problem. mike -- Mike Meyer m...@mired.org http://www.mired.org/ Independent Software developer/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Build tool for mixed Clojure/Java projects
On Mon, 11 Jul 2011 21:12:20 -0400 Ken Wesson kwess...@gmail.com wrote: On Mon, Jul 11, 2011 at 7:51 PM, Mike Meyer m...@mired.org wrote: On Mon, 11 Jul 2011 16:21:45 -0400 Ken Wesson kwess...@gmail.com wrote: So, repository does not imply server at all, This is getting silly. Repository is a word that brings immediately to mind typing checkin and checkout commands at a command prompt in order to work on source code that is stored remotely. And remotely implies server. I was with you until you said stored remotely. there's also a server in there, or even multiple servers. The alternatives I can think of are: 1. One developer, one computer. 2. Many developers, one computer. No remote storage and if the developers are co-located no server; otherwise a terminal server. The former is obviously not parallelizable (though edit conflicts are thus a non-issue -- single global lock FTW!!!1!1) and the latter is a throwback to the 1980s or earlier. :) Most systems that support such a model - and yes, they're still being both developed and used - are well enough written to avoid a single global lock. 3. Many computers, one developer 4. An ad hoc, peer-to-peer system with many evolving versions of the codebase and patches swapped back and forth This is the model used by the Linux kernel, among others. You might argue that one of Linus's repositories is a master copy, as that's the one that Linux kernel releases are cut from, but that's really the only thing that distinguishes it from any of the others. Each developer gets to decide where they want to take patches from and which patches they're actually going to use in any given build, but most can't put code in the so-called master repository. So, unless 4 can be made workable, I'd say a project with 14 million LOC and thousands of developers using it for five years demonstrates that it's both workable and scalable. mike -- Mike Meyer m...@mired.org http://www.mired.org/ Independent Software developer/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Build tool for mixed Clojure/Java projects
On Tue, 12 Jul 2011 18:13:57 -0400 Ken Wesson kwess...@gmail.com wrote: On Tue, Jul 12, 2011 at 2:31 PM, Mike Meyer m...@mired.org wrote: You write clearly enough that misinterpretation isn't likely. You were simply making false statements. I do not do that, and I won't tolerate being called names and badmouthed in public. This discussion is over. I'm sorry, I didn't mean to imply that you were lying. I'm sure you thought the statements were true. You were just wrong in this case. mike -- Mike Meyer m...@mired.org http://www.mired.org/ Independent Software developer/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Build tool for mixed Clojure/Java projects
On Tue, 12 Jul 2011 18:20:38 -0400 Ken Wesson kwess...@gmail.com wrote: On Tue, Jul 12, 2011 at 3:11 PM, Mike Meyer m...@mired.org wrote: On Mon, 11 Jul 2011 21:12:20 -0400 Ken Wesson kwess...@gmail.com wrote: 2. Many developers, one computer. No remote storage and if the developers are co-located no server; otherwise a terminal server. The former is obviously not parallelizable (though edit conflicts are thus a non-issue -- single global lock FTW!!!1!1) and the latter is a throwback to the 1980s or earlier. :) Most systems that support such a model - and yes, they're still being both developed and used - are well enough written to avoid a single global lock. Another misunderstanding. Many developers working at one physical, co-located computer has the keyboard and monitor as a single global lock. In the terminal server case there could be a finer locking granularity. As for still developed and used, what for? What makes you think a computer can have only a single keyboard/monitor? After all, what is a terminal server but a computer with lots of keyboard/monitors that routes the terminals out to network servers of some kind? But this is all irrelevant - from the point of view of an application, it doesn't make any difference if someone is issuing commands from a device directly connected to the hardware, from a device connected to a terminal server, or sitting at a second computer and connected back to the single computer where the work is being done. Which is why such things are still being developed. There's fundamentally no difference between many developers running commands on the single computer to manipulate the data and many developers running clients that talk to apache running on that single computer and causing it to issue those commands. This lets a developer leverage the apache networking code to create a client/server model, and most modern SCMs can be run that way. 4. An ad hoc, peer-to-peer system with many evolving versions of the codebase and patches swapped back and forth This is the model used by the Linux kernel, among others. You might argue that one of Linus's repositories is a master copy, as that's the one that Linux kernel releases are cut from, but that's really the only thing that distinguishes it from any of the others. Each developer gets to decide where they want to take patches from and which patches they're actually going to use in any given build, but most can't put code in the so-called master repository. Which means it's not really case 4 at all. Well, it's very clearly not cases 1, 2 or 3. There are many developers and many computers, and case 4 is the only one that allows for that. So this is either case 4, or you need to provide another case for it. So, unless 4 can be made workable, I'd say a project with 14 million LOC and thousands of developers using it for five years demonstrates that it's both workable and scalable. Except that it has an official build repository with more stringent criteria for what gets in there, so not really. Half right. As I said, it's got one repository that the official builds come from. Other people are free use builds from their own repositories, and often do - I don't think any of the GNU/Linux distributions actually use binaries built by Linus. Instead, they each have their own master repository from which they do their official builds. However, the criteria for what gets into that so-called master repository are no more stringent than for any other repository in the project: only patches the owner wants get in. mike -- Mike Meyer m...@mired.org http://www.mired.org/ Independent Software developer/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Build tool for mixed Clojure/Java projects
On Mon, 11 Jul 2011 07:51:33 -0400 Ken Wesson kwess...@gmail.com wrote: On Sun, Jul 10, 2011 at 2:01 AM, mike.w.me...@gmail.com m...@mired.org wrote: [snip most of post whose sole purpose seems to be to gainsay anything I write] Because in that article, you were (unusual for you) way off base. The only source control system I know that uses an ACID database doesn't need a back end server. How exactly is this possible? Databases *are* servers. Database and DBMS are used more-or-less synonymously (when database isn't used more broadly than ACID/SQL/etc.) and the S in DBMS stands for server. SQL is to databases/clients as HTTP GET/POST syntax is to web servers/browsers. Etc. I explained it in the part you snipped, but I'll repeat it for you: it uses an embedded database. A database is *not* a server, it's an API. The API may well talk to a server - and most do - but there's no requirement that it do so. This particular embedded database is almost certainly the most popular SQL database in the world, with hundreds of millions of installations running worldwide. SQL doesn't have a position anything like HTTP GET/POST syntax. HTTP's GET/POST syntax is a wire protocol. Once you it, you can write code to talk to a server, and get a response. If you know SQL, you can't use a database *at all*. You have to know an API for the database in question - and if it's a server, have an implementation that talks it's wire protocol. ODBC provides a standard API, but not a wire protocol. Last time I looked, there wasn't a standard wire protocol for SQL servers. mike -- Mike Meyer m...@mired.org http://www.mired.org/ Independent Software developer/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Build tool for mixed Clojure/Java projects
On Mon, 11 Jul 2011 16:21:45 -0400 Ken Wesson kwess...@gmail.com wrote: So, repository does not imply server at all, This is getting silly. Repository is a word that brings immediately to mind typing checkin and checkout commands at a command prompt in order to work on source code that is stored remotely. And remotely implies server. I was with you until you said stored remotely. These days, I almost *never* do checkins or checkouts to a remote server - and I use four different source control systems on a regular basis: (hg, git, fossil perforce). The first three *cannot* do remote checkins or checkouts - they require the repository be stored on the local disk. The last one is the only one that behaves the way you describe - and it's a legacy system I'm trying to get rid of. mike -- Mike Meyer m...@mired.org http://www.mired.org/ Independent Software developer/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Learning Idiomatic Clojure
On Wed, 11 May 2011 19:10:13 -0700 (PDT) J.R. Garcia mrjohngar...@gmail.com wrote: I'm wondering what resources would be best to learn how Clojurians write their code. I've been developing for about 4 years in several object-oriented languages (mostly C# and Ruby). I understand Clojure's syntax well and I'm familiar with a lot of the features of Clojure (although I'm sure several of you would prove me wrong). One problem I keep running into is how to attack a problem the Clojure way. I often find myself writing Clojure like I would write C# code with LINQ, only in Clojure's syntax. As others have said, this sounds like you need a book on functional/LISP programming. There are some excellent books for other LISP dialects. Structure and Interpretation of Computer Programs (aka SICP) would be my recommendations, but Practical Common Lisp and On LISP are both excellent. I don't know of a book at that quality level using Clojure. There is an effort underway to translate SICP to clojure at http://sicpinclojure.com/. I'm not interested in Java interop or Clojure on the web or Clojure's syntax. I've had no problem finding answers for those things on the Internet. I'm really more interested in stuff like http://www.bestinclass.dk/index.clj/2010/10/taking-uncle-bob-to-school.html, but covering a wider range of things rather than a small example. I'm interested in any resource whether it's a book, a video, a blog, a person, etc. This, no the other hands, is a little bit contradictory. The example about syntax and white space than writing code the Clojure way, though you explicitly say that's not what you're interested in. Seems like you're asking for a community style guide. Again, I don't know that such exists. If it does, Google didn't find it, thought it sounds like a good idea if someone wanted to write one - maybe starting with a LISP or Scheme style guide (there are lots of those to choose from). mike -- Mike Meyer m...@mired.org http://www.mired.org/ Independent Software developer/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Learning Idiomatic Clojure
On Thu, 12 May 2011 07:45:50 -0700 (PDT) Adam Burry abu...@gmail.com wrote: On May 12, 11:54 am, Mike Meyer m...@mired.org wrote: As others have said, this sounds like you need a book on functional/LISP programming. There are some excellent books for other LISP dialects. Structure and Interpretation of Computer Programs (aka SICP) would be my recommendations, but Practical Common Lisp and On LISP are both excellent. I don't know of a book at that quality level using Clojure. There is an effort underway to translate SICP to clojure athttp://sicpinclojure.com/. Obviously, these are excellent texts, but I wonder if a Haskel book might be better place to look. The problem is I have not looked at any Haskel books, but I expect it would be a better place to read about the joys of laziness. SICP and On LISP both deal with lazy data structures, but as a special case. While clojure has the same data structures, their libraries don't seem to try and conserve it the way that Clojure libraries do, so those are probably inadequate for people doing clojure. I think Haskell might take you to far the other way, since everything is lazy, which changes things radically. The best I know of here would be Concepts, Techniques, and Models of Computer Programming, but that takes you well away from Clojure's mostly-functional paradigm. I suspect that dealing properly with Clojure's laziness is a topic for a clojure-specific book. mike -- Mike Meyer m...@mired.org http://www.mired.org/ Independent Software developer/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Reading clojure code of larger domain specific projects
On Mon, 9 May 2011 03:24:44 -0700 (PDT) Chris Perkins chrisperkin...@gmail.com wrote: I have been thinking for while that it would be great to have something equivalent to book clubs for reading code. A group could meet weekly, all having read the same moderate-sized project, and discuss. I wonder if this could be made to work as a web-app, where you can sign up, state your areas of interest, and have a weekly reading assignment emailed. Then you could meet on IRC or something. Just a thought. I've been thinking about a similar thing. Lists for beginners at a language include frequent requests to evaluate my code. I've been wondering if there would be any interest in a forum where you could post a bit of code and let others comment on it. It'd need some way of picking a language (specific forums? A tag on the post?). One thing that happens to such posts is they turn into threads of best way to solve this problem - where best varies by author. Similarly, programming problem set sites are popular. So maybe an option for How would I do this might be useful. mike -- Mike Meyer m...@mired.org http://www.mired.org/ Independent Software developer/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: What is the purpose of the Identity function?
On Sat, 7 May 2011 12:09:45 -0700 Sean Corfield seancorfi...@gmail.com wrote: Identity on its own isn't really useful - but in combination with higher-order functions, it can be very indispensible! Bingo. An HOF accepts a function that filters/mogrifies data before processing it in some way. Sometimes, you *don't* want to have that extra step. There are two ways to do that: one is to have two variants of the HOF - one which uses the function, and one which doesn't (which may mean it's not an HOF). The other is identity. Clojure does both, depending. You can see the first in sort and sort-by, where sort-by uses a keyfn to extract keys from items in the collection. You could just identity for the keyfn to sort by items, but this case is so common it gets it's own function - sort. Similarly, filter takes a predicate to check which items need to be removed. If you just want to remove false values, the appropriate predicate is identity. This case isn't very common, so there's no second version. mike -- Mike Meyer m...@mired.org http://www.mired.org/ Independent Software developer/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: dead simple compile to jar file
On Wed, 27 Apr 2011 10:45:58 -0700 (PDT) cej38 junkerme...@gmail.com wrote: Hi, I would like the simplest method to compile a few lines of clojure code into a jar file that I can distribute to some fellow scientists that don't know much (if anything) about java or clojure. Since I am not creating a huge product that I will be updating often, maven and Lenningen seem like overkill. The compiled jar file should contain the relevant clojure and clojure.contrib stuff within it, so that the other users don't have to worry about downloading clojure/contrib. Also, I would rather not unpack jar files from libraries that I used, if possible. Clojure's compile function is tantalizing, but then everyone would need to have the same versions of the libraries that I used, not just clojure and contrib. This is one of the holes in the Clojure/Java infrastructure - things that should be simple aren't. So there isn't anything simpler than a project except the bare file manipulation commands. To use those commands, you need to compile all your clojure files to class files (via the clojure compile command), then use the jar command to create the uberjar (still a .jar) file that contains all the relevant .class files, and also the contents of the .jar files that your program depends on. Unlike most compiled languages, there isn't a driver program available that will take a list of files on the command line and compile them, then put the results together to what you want. Instead, you have to rely on project manipulation tools like ant, lein or maven to take a file describing the project and do all that for you. While I agree with you that things like lein are overkill for this kind of thing, they're still probably the simplest solution you're going to find. It's probably easier to figure out how to use lein to build your uberjar than to figure out how to get jar to create the same thing. Sadly, I don't see this situation changing. Java people seem to think this is normal, and suggest that Clojure isn't the right language (what they mean is that Java isn't the right environment) when it gets pointed out. So even if someone wrote a jc command that knew how to compile Java, Clojure, Scala, Groovy, JRuby, Jython, etc. and which jar files to add for each of them, I suspect it wouldn't get any mind share in those communities because there isn't a lot of interest in tools to make simple things simple. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Software developer/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Start Clojure programs from Eclipse
On Sun, 24 Apr 2011 01:07:45 -0400 Ken Wesson kwess...@gmail.com wrote: On Sun, Apr 24, 2011 at 12:01 AM, Mike Meyer m...@mired.org wrote: On Sat, 23 Apr 2011 23:42:23 -0400 Ken Wesson kwess...@gmail.com wrote: On Sat, Apr 23, 2011 at 11:35 PM, Mike Meyer m...@mired.org wrote: On Sat, 23 Apr 2011 23:19:53 -0400 Ken Wesson kwess...@gmail.com wrote: On Sat, Apr 23, 2011 at 8:13 PM, Mike Meyer m...@mired.org wrote: On Sat, 23 Apr 2011 19:41:28 -0400 Ken Wesson kwess...@gmail.com wrote: or you live in a universe where cosmic rays can flip bits and other sources of hardware hiccups exist. Software crashes caused by non-software-bug-triggered memory corruption seem to me to be exceedingly rare, and they could as easily strike critical parts of the operating system as a multithreaded server program (and a large batch of independent C jobs will occupy more memory and have a correspondingly larger cross section as a target for such things). The best recourse if the server gets hit by something like that is going to be to reboot it. While it might be exceedingly rare on a per-cpu-second basis, if your application runs 7x24 on enough cpus, you can expect to see them at regular intervals. In which case the best recourse - if you want a stable, robust application - is to restart the smallest set of processes that might have been affected by the problem. In other words, all of them, since the operating system might have been affected by such a problem and if it was, everything else is probably affected too. Let me guess - you're one of these people who Ah, I get it. You're arguing because you have some kind of *personal* issue, rather than for any logical reason. Yup. Years of practical experience building and running such systems. Logic and theory seldom survive contact with practice unscathed. Sure, a hardware glitch that affects the OS means you should reboot the system. And assuming you can even detect that such a glitch has occurred at all (what if one hits the code doing the detecting, or the memory that it uses -- or the operating system, in a way that affects that code?) can you detect whether or not it hit the operating system? If your hardware doesn't take a parity fault or correct the data most of time it tries to read such data, you need better hardware. Anything that needs the data that's corrupt needs to be killed - which means that user process if the data is in user space. The kernel will be fine, because it can't have used the bad data without triggering the fault. Of course, if it affects some user process, it may have affected the OS without leaving evidence of doing so. Then again, it may not have. While you could reboot everything just in case, you could also have a hardware glitch affect the OS without leaving evidence in any process, so you might as well reboot even though nothing is wrong just in case. Obviously there's little point in rebooting absent *some* evidence that something is wrong. Exactly. If the kernel isn't complaining about something, that's exactly what you have - absence of evidence that something is wrong with the kernel. Some user process failing for an unknown reason doesn't provide any evidence that something is wrong with the kernel. Of course, some process segfaulting doesn't mean much if it's a typical C program. On the other hand, if you have a rock-solid JVM and kernel and various JVM bytecodes running, and the JVM faults, the likelihood of a problem like this is higher than if a random other program faulted -- indeed, either it's a JVM bug, an OS bug, or a glitch of the type being discussed, since arbitrary bytecode on a bug-free JVM shouldn't cause the JVM to fault. (Native methods complicate things somewhat though.) Since neither the JVM bug nor the OS bug get fixed by restarting the system, and the process that has glitched will most likely be fixed equally well by restarting it as by rebooting the system, there's no evidence to indicate a problem that would be helped in any way by rebooting the system. Nah, hardware glitches are either localized, in which case restarting just the address spaces that failed is sufficient (and has proven so in practice for years), or they're systemic, in which case you'll have failures throughout the system. It's pretty easy to tell the difference between the two and deal with them appropriately. Easy for who? The system administrator? I thought we were considering automated means of recovering faulting systems here. Easy for automated systems to deal with. Foo is failing repeatedly, quit restarting it and escalate the issue and Multiple failures on foo, create an escalated issue are both standard behaviors for application monitoring tools. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Software developer/SCM consultant, email for more
Re: Start Clojure programs from Eclipse
On Sat, 23 Apr 2011 19:41:28 -0400 Ken Wesson kwess...@gmail.com wrote: Well, Java servers probably are yes, but traditional Unix servers would normally fork a new process for each incoming connection. Poor man's threads. Although the insulation of each one against crashes in the others might be useful when you're coding in a language with memory management tools as primitive as C's. ;) Or your tools for handling concurrency are as poor as C's (which is unfortunately most popular languages), or you live in a universe where cosmic rays can flip bits and other sources of hardware hiccups exist. starting a pool of processes to avoid the startup time of a new process when a new client connects. With small lightweight C processes and some suitable system for IPC, this can work. With JVMs, not so much, unless you have RAM coming out of your ears. JVM processes tend to be fairly large; it wouldn't take many 64MB java.exe jobs to start the pagefile thrashing. Even with an 8GB server, you start paging at 128 simultaneous connections in that case, and you certainly can't handle thousands. I would have expected large chunks of the JVM processes to be shared between parent and child - especially before the first accept returns. In particular, the VM implementation and the compiled JVM bytecodes should all be shared. Data structures JIT'ed code - well, it will depend on a variety of implementation details, but they all start on shared pages with a COW bit set. Of course, if you're using threads in the parent for other things, then forking to create new processes creates a bunch of interesting things to deal with. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Software developer/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Start Clojure programs from Eclipse
On Sat, 23 Apr 2011 23:19:53 -0400 Ken Wesson kwess...@gmail.com wrote: On Sat, Apr 23, 2011 at 8:13 PM, Mike Meyer m...@mired.org wrote: On Sat, 23 Apr 2011 19:41:28 -0400 Ken Wesson kwess...@gmail.com wrote: or you live in a universe where cosmic rays can flip bits and other sources of hardware hiccups exist. Software crashes caused by non-software-bug-triggered memory corruption seem to me to be exceedingly rare, and they could as easily strike critical parts of the operating system as a multithreaded server program (and a large batch of independent C jobs will occupy more memory and have a correspondingly larger cross section as a target for such things). The best recourse if the server gets hit by something like that is going to be to reboot it. While it might be exceedingly rare on a per-cpu-second basis, if your application runs 7x24 on enough cpus, you can expect to see them at regular intervals. In which case the best recourse - if you want a stable, robust application - is to restart the smallest set of processes that might have been affected by the problem. In some cases, that is the server. In others, it's a single process. In still others, it's the set of servers participating in a distributed application. starting a pool of processes to avoid the startup time of a new process when a new client connects. With small lightweight C processes and some suitable system for IPC, this can work. With JVMs, not so much, unless you have RAM coming out of your ears. JVM processes tend to be fairly large; it wouldn't take many 64MB java.exe jobs to start the pagefile thrashing. Even with an 8GB server, you start paging at 128 simultaneous connections in that case, and you certainly can't handle thousands. I would have expected large chunks of the JVM processes to be shared between parent and child - especially before the first accept returns. That happens forking C programs. It won't happen starting up separate, independent JVM processes, and I don't know how a JVM will handle it if a native method calls fork() but I somehow doubt it will all just work peachily. Ah, good point. I don't think in Java, so forget that it doesn't necessarily have access to all the facilities of the underlying OS. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Software developer/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Start Clojure programs from Eclipse
On Sat, 23 Apr 2011 23:42:23 -0400 Ken Wesson kwess...@gmail.com wrote: On Sat, Apr 23, 2011 at 11:35 PM, Mike Meyer m...@mired.org wrote: On Sat, 23 Apr 2011 23:19:53 -0400 Ken Wesson kwess...@gmail.com wrote: On Sat, Apr 23, 2011 at 8:13 PM, Mike Meyer m...@mired.org wrote: On Sat, 23 Apr 2011 19:41:28 -0400 Ken Wesson kwess...@gmail.com wrote: or you live in a universe where cosmic rays can flip bits and other sources of hardware hiccups exist. Software crashes caused by non-software-bug-triggered memory corruption seem to me to be exceedingly rare, and they could as easily strike critical parts of the operating system as a multithreaded server program (and a large batch of independent C jobs will occupy more memory and have a correspondingly larger cross section as a target for such things). The best recourse if the server gets hit by something like that is going to be to reboot it. While it might be exceedingly rare on a per-cpu-second basis, if your application runs 7x24 on enough cpus, you can expect to see them at regular intervals. In which case the best recourse - if you want a stable, robust application - is to restart the smallest set of processes that might have been affected by the problem. In other words, all of them, since the operating system might have been affected by such a problem and if it was, everything else is probably affected too. Let me guess - you're one of these people who reboots systems every couple of days just in case? Sure, a hardware glitch that affects the OS means you should reboot the system. Of course, if it affects some user process, it may have affected the OS without leaving evidence of doing so. Then again, it may not have. While you could reboot everything just in case, you could also have a hardware glitch affect the OS without leaving evidence in any process, so you might as well reboot even though nothing is wrong just in case. Nah, hardware glitches are either localized, in which case restarting just the address spaces that failed is sufficient (and has proven so in practice for years), or they're systemic, in which case you'll have failures throughout the system. It's pretty easy to tell the difference between the two and deal with them appropriately. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Software developer/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Shebang support for cljr
On Wed, 20 Apr 2011 10:16:05 -0700 (PDT) David Jacobs develo...@allthingsprogress.com wrote: What's the status on this? One of the reasons I don't use Clojure everyday, much as I like it, is that I want it to integrate seamlessly with Unix for scripting. Um, I've been using it with shebang scripts for a while now. You've got to do the usual interpreted interpreter double-script dance, though: 1) Write a shell script that launches java running the clojure main with all your favorite libraries somewhere on CLASSPATH. 2) Start your scripts with #!/usr/bin/env scriptname where scriptname is the clojure script you wrote in step 1. Performance pretty much sucks - starting the jvm is just slow. You can solve that with nailgun (or something similar), which will let you use the nailgun binary as the interpreter (i.e. #!/usr/bin/env/clojure where clojure is a copy/symlink to the nailgun binary), but you have to remember to start the nailgun server. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Software developer/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Shebang support for cljr
On Thu, 21 Apr 2011 01:30:25 +0800 Ambrose Bonnaire-Sergeant abonnaireserge...@gmail.com wrote: On Thu, Apr 21, 2011 at 1:28 AM, Mike Meyer m...@mired.org wrote: Performance pretty much sucks - starting the jvm is just slow. You can solve that with nailgun (or something similar), which will let you use the nailgun binary as the interpreter (i.e. #!/usr/bin/env/clojure where clojure is a copy/symlink to the nailgun binary), but you have to remember to start the nailgun server. Jark uses a persistent JVM so it's very nice to use for this task. Yup - it uses nailgun (though apparently nrepl is also available). Seems like it improves nailgun for clojure users, but hides features that would be useful if you're using other JVM-based languages with it - which is why it requires the double-script dance even though nailgun doesn't. You still have to remember to start the thing. Which surprises me. Seems like there should be an option to these things to let the client start the server if it's not running. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Software developer/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: help--reading keyboard input from Clojure is surprisingly difficult
On Sat, 9 Apr 2011 19:27:13 -0400 Lee Spector lspec...@hampshire.edu wrote: On Apr 9, 2011, at 6:18 PM, Sean Corfield wrote: On Sat, Apr 9, 2011 at 6:46 AM, Lee Spector lspec...@hampshire.edu wrote: But still, I will humbly submit that it's totally freakin' nutso that it should be so hard to do basic user interaction. I'm curious as to what percentage of developers are writing console-based applications (in any language)? I don't know -- probably quite low -- but I would predict that the percentage of students learning Lisp-like languages who would be writing console-based interactive programs is quite high. I wouldn't expect it to be quite low, but I build them regularly, and so do most of the people I work with. On unix systems, the predominate way to plug to programs together is still via the standard IO pipes, which the programs - even if normally invoked from some visual tool - can be used from the command line. And many of us work develop on one system, then deploy on something else via SSH, so being able to deal with things on the command line - even if it also provides some kind of GUI - is a useful feature. Admittedly, JVM languages don't lend themselves to such things, what with having to either start it on every command or have some kind of server running to avoid that. Code for doing this sort of thing in Common Lisp or Scheme looks almost identical to the simple Clojure code we've seen on this thread, with the most significant difference being that the Clojure version apparently doesn't work if you launch your REPL and run your code in some of the commonly recommended ways. This sounds more like an issue with those commonly recommended ways than with clojure or it's REPL, since it works fine running from a shell. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Software developer/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: What the hell is going on with the Clojure cheat sheet?
On Tue, 5 Apr 2011 10:00:28 -0400 Ken Wesson kwess...@gmail.com wrote: And why would it come up as a page full of ads (mostly pretty scammy looking ads, like fake Windows messageboxes and such) instead of a Host Unknown error?! Because the registrar for clojure.org chose to resolve lapsed domain names to a page that it thinks could make it some money instead of failing. If you look closely (assuming you can still get the page), you're liable to find a buy this domain link somewhere on it. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Software developer/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Clojure Code Highlighting in Presentations
On Sun, 3 Apr 2011 18:15:43 +0200 Heinz N. Gies he...@licenser.net wrote: Hi everyone, not a clojure technical question but it has to do with the entire topic :). I know there have been some presentations about clojure already and would like to ask for some best practice experience regarding embedding Clojure code in a presentation. Any advice? What tools did you people use for coloring the code in slides? I'd be very thankful for some hints and pointers in the right direction so I don't have to reinvebt the wheel :). I use enscript for highlighting source code - it can generate pretty nearly anything you'd ever want. I've got a state file for clojure you'll need if you want to highlight clojure code. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Software developer/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Pointer errors?
On Thu, 31 Mar 2011 16:51:20 -0400 Stuart Halloway stuart.hallo...@gmail.com wrote: This is just *strange*. I'm working on converting a servlet that has hardwired vectors of values to read those values from a database. Given that this is simple, I'm using clojure.contrib.sql and an sqlite plugin. Those vectors get walked in the init code to create the hashmap that drives page rendering and any actions the servlet takes. The code change plan is: 1a) Convert vector of vector of strings to vector of hashmaps from keyword to strings. 1b) Tweak processing function in walk call to use :keys to destructure instead of vector destructuring. 2) Test and commit these changes. 3) Replace reference to hardwired vectors with call to with-query-results to read in essentially the same data. 4) Test and commit these changes. Ok, I started with a working servlet. I started seeing oddball tracebacks after after doing steps 1a 1b - no new libraries involved. I can reproducibly but get tracebacks, but some parts of the servlet work fine. The tracebacks look like: java.lang.RuntimeException: java.lang.NullPointerException at clojure.lang.LazySeq.sval(LazySeq.java:47) at clojure.lang.LazySeq.seq(LazySeq.java:56) at clojure.lang.RT.seq(RT.java:450) at clojure.core$seq.invoke(core.clj:122) at clojure.core$r.invoke(core.clj:793) at clojure.core$reverse.invoke(core.clj:806) at clj_stacktrace.core$trim_redundant.invoke(core.clj:86) at clj_stacktrace.core$parse_cause_exception.invoke(core.clj:104) at clj_stacktrace.core$parse_exception.invoke(core.clj:122) at ring.middleware.stacktrace$html_ex_view.invoke(stacktrace.clj:25) at ring.middleware.stacktrace$html_ex_response.invoke(stacktrace.clj:40) at ring.middleware.stacktrace$ex_response.invoke(stacktrace.clj:51) at ring.middleware.stacktrace$wrap_stacktrace$fn__1571.invoke(stacktrace.clj:61) at ring.util.servlet$make_service_method$fn__1842.invoke(servlet.clj:117) at x10.war$_service.invoke(war.clj:19) at x10.war.service(Unknown Source) at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511) at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:390) at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216) at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182) at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765) at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:440) at org.mortbay.jetty.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:230) at org.mortbay.jetty.handler.HandlerCollection.handle(HandlerCollection.java:114) at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152) at org.mortbay.jetty.Server.handle(Server.java:326) at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542) at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:926) at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:549) at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:212) at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404) at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:410) at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582) [Speculation elided...] Ok, maybe it's a threading/agent issue. That would explain the once but never again behavior, if the agent got into the FAILED state. Could that corrupt something that might make jetty and/or ring fail as above? Except then why do the pages that just render HTML and not send work to the agent still work? Grrr. Anyone got any clue bits (any at all) I can borrow? Hi Mike, It appears that you aren't seeing the actual error (whatever it may be) because of a bug in clj_stacktrace. That was enough of a hint to chase the problem down: the agent was failing, for two reasons. One was a code bug. The other (which caused it to be erratic) was that it is serializing access to a reusable resource, and if I left the resource opened in the REPL, the agent would fail. That's what caused the erratic behavior that was driving me nuts. Thanks, mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Software developer/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members
Init timing for ring web servlet running on Jetty?
I finally got back to the web app that needed init'ing before processing requests, and got that working (not quite as straightforward as the various mails/docs make it look). The problem now is that the init runs when the first request comes in after the app has been started. While this works, it does mean that first request takes a *long* time to process. Things after that run pretty much instantly (as the main thread just renders the html), but that one takes 10s of seconds. I realize this is probably the wrong place to ask, but Google hasn't been much help, and I have no idea what forums would be appropriate for asking about such things (ring? jetty? Some servelet-developers forum?), so... Is there some way to convince Jetty (or tomcat, or ...) to run the init methods of a servlet before the first request comes in? Or maybe a pointer to the appropriate forum? Thanks, mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Software developer/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Init timing for ring web servlet running on Jetty?
On Thu, 31 Mar 2011 06:55:08 -0400 Allen Johnson akjohnso...@gmail.com wrote: Is there some way to convince Jetty (or tomcat, or ...) to run the init methods of a servlet before the first request comes in? Or maybe a pointer to the appropriate forum? You can tell a servlet to init on startup with something like this in your web.xml: servlet servlet-nametest-servlet/servlet-name servlet-classmyapp.servlet/servlet-class load-on-startup1/load-on-startup /servlet This tells the container to initialize the servlet before any requests. The number is just the ordering in which the servlets are initialized. Cool. Worked like a charm. Thanks. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Software developer/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Pointer errors?
the SQL code. This is why I think the code is irrelevant. I'm pretty much at a loss here - got no idea what to try next. The most relevant thing google turned up was a bug in the version of leingingen I was using - it sometimes omitted a class file building uber[jw]ars (except why does the same thing appear to work once and not the second time?), so I upgraded lein, which didn't help. Ok, maybe it's a threading/agent issue. That would explain the once but never again behavior, if the agent got into the FAILED state. Could that corrupt something that might make jetty and/or ring fail as above? Except then why do the pages that just render HTML and not send work to the agent still work? Grrr. Anyone got any clue bits (any at all) I can borrow? Thanks, mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Software developer/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Leiningen capabilities (was Re: A newbie's summary - what worked, what didn't)
On Tue, 29 Mar 2011 16:49:48 -0700 (PDT) Phil Hagelberg p...@hagelb.org wrote: On Mar 28, 10:24 pm, Andy Fingerhut andy.finger...@gmail.com wrote: And I should have known about this before, but had not used it. It adds to Leiningen the capability to search, and I'm not sure, but perhaps also add dependencies that were found: https://github.com/Licenser/lein-search The part that modifies project.clj to insert new dependencies will probably not be merged because 0) abritrary code may be embedded in project.clj, so the :dependencies list is not necessarily a data structure you can just splice however you feel like and 1) it's basic text editing; asking Leiningen to do it for you is hardly more convenient than doing it yourself. It could be done in a 3rd-party plugin with caveats that it will not always work correctly though. Being able to type lein add library and have it take care of everything is a lot more convenient than typing lein search library, selecting the appropriate stretch of text, copying it to the clipboard (or not, if you're brave), switching to an editor, finding the right place to insert it, pasting the clipboard, then saving the file. This seems to be a downside to switching from XML to Clojure. Not that I think that was a bad idea - the upsides far outweigh this. Maybe project.clj should be automatically merged with a project.xml when lein runs, where project.xml is created with a for machine editing only - humans edit project.clj comment at the top. Then tasks could edit project.xml without running into those problems. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Software developer/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: updating a map value
On Wed, 30 Mar 2011 10:21:41 -0700 (PDT)
Jeff Rose ros...@gmail.com wrote:
Hola,
I'm looking for a function that updates a map value by calling a
function on it.
(def foo {:a 1})
So instead of this:
(assoc foo :a (inc (:a foo))); = {:a 2}
Something like this:
(map-fn foo :a inc); = {:a 2}
Does that exist somewhere, or should I be doing this in a different
way? If not, shouldn't it be included?
Possibly you want update-in:
(update-in foo [:a] inc); - {:a 2}
I'm not sure why there's not an update that replaces the list of
keys with a single key.
mike
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Re: A newbie's summary - what worked, what didn't
On Sun, 27 Mar 2011 21:30:54 -0700 (PDT) ultranewb pineapple.l...@yahoo.com wrote: But with any other language I've ever used, at most I include a library I need in a directive at the top, or I include my own code in a similar directive. Question: how did you find the library you were going to use? If you only searched your local system, then yeah, a well-designed system/language/etc. installed by somebody competent will do that for you And I agree with you - to the best of my knowledge, Java (and from what I can tell, pretty much anything based on the JVM) fails at this. But this also means you're liable to be missing a large chunk of the tools available for the language. These days, most languages have contributed code libraries large enough that installing them all is impractical on most systems. Searching those for things requires accessing a database of some sort over the network. Installing them involves downloading the library from some network site and doing whatever needs to be done to install it. So, assuming you found a library you really needed that wasn't already locally installed, how did you deal with that? If you could add a require library to your source and your language would go find it, download it and install it, I'd like to know about that language. If you had to ask someone else to install it for you, then you're probably right that someone else was paid to deal with these issues. Having been that person, I'll let you know that you had it *really* easy if you didn't have to specify what version of a library you wanted as well as the name. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Software developer/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Jesus, how the heck to do anything?
On Thu, 24 Mar 2011 06:22:49 -0700 (PDT) Meikel Brandmeyer m...@kotka.de wrote: On 24 Mrz., 13:09, Baishampayan Ghose b.gh...@gmail.com wrote: IMHO the Java bashing is overrated. Coming from a polyglot-but-non- java background, I didn't have much trouble getting things running. Is the CLASSPATH really so much different to the PYTHONPATH, LD_LIBRARY_PATH or even the plain old PATH itself? Actually, that would be Java infrastructure bashing. Java-bashing would be complaining about lack of multiple inheritance, the protection mechanisms it inherited from C++, the variable declaration syntax it inherited from C (anyone care to name another language with a variable declaration syntax baroque (or broke) enough to cause someone to write a program to translate between it and English?), etc. There does appear to be one major difference (at least on Unix) between CLASSPATH and your examples: the default values work for simple scripts. In the case of PYTHONPATH LD_LIBRARY_PATH, the default is unset, and the infrastructure takes care of checking the obvious places for things. Maybe that's also true with a good Java install, and the default clojure install just isn't java-aware enough to put the clojure jar files in the right place. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Software developer/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Jesus, how the heck to do anything?
On Wed, 23 Mar 2011 00:50:10 -0700 (PDT) ultranewb pineapple.l...@yahoo.com wrote: Short version: How do I just open an editor, type in some Clojure code, save it in a file, and then run it? Long version: Okay, I'm very new to Clojure. But I'm not a Java programmer (don't want to be). I don't think you can get very far in Clojure without having to come to grips with the Java infrastructure. It ain't Unix. Anyway, I wrote http://www.mired.org/writing/a-guide-to-javaless-clojure to help people get as far as possible without having to deal with the that infrastructure. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Software developer/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Jesus, how the heck to do anything?
On Wed, 23 Mar 2011 15:55:51 -0700 (PDT) ultranewb pineapple.l...@yahoo.com wrote: On Mar 24, 1:11 am, Mike Meyer m...@mired.org wrote: Long version: Okay, I'm very new to Clojure. But I'm not a Java programmer (don't want to be). I don't think you can get very far in Clojure without having to come to grips with the Java infrastructure. It ain't Unix. Well, for me I guess it will depend on how much coming to grips I have to do. If it is much more than clicking on some automation tool to generate boilerplate (leinengen?), or typing in java -jar blah blah at a command prompt, I'm outta here. I have been offered money to program in java in the past. I turned it down, turning the phrase you couldn't pay me to program in java into a reality. It's fair to state that I hate java more than any other language. I'd rather program in COBOL than java. I tend to agree - and I've written just enough of both to give that statement some weight. Then again, I used to say that the major difference between programming in COBOL and digging ditches is that programming in COBOL pays better. The thing is, you can deal with the Java infrastructure without having to write any Java. They use XML files for everything, so you wind up writing lots of little and not-so-little XML files to use the infrastructure. The Clojure community is building tools that let you write S-expressions (as understood by Clojure) instead of those XML files. They either replace some Java tool, or produce the XML for you. I'm not sure going from Java to XML is a win. I *am* sure that going from XML to S-expressions is a win. But that still leaves you with a lot of infrastructure (when compared to a unix philosophy equivalent) to deal with to do things that are reasonable tasks for JVM-based tools. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Software developer/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: How to Sum a Sequence?
On Sun, 20 Mar 2011 08:47:30 -0700 (PDT) Christian soulbea...@gmail.com wrote: Hello Tassilo! I've tested your code and looked at the Clojure Documentation for 'for'. Given that, I have written (reduce +(filter even? (for [fib (fib-seq) :while ( fib 400)] fib))) This gives me the error 'clojure.lang.LazySeq cannot be cast to clojure.lang.IFn'. I think this is because fib-seq is a var, not a function (although I was hard-pressed finding out what IFn stood for.) When I omit the () with [fib (fib-seq)...], the program works just as expected. Since nobody answered the implied question: yes, you're right. The fix is to just remove the ()'s from fib-seq to reference it directly, like so: (reduce + (for [fib fib-seq :while ( fib 400) :when (even? fib)] fib)) Note that I replaced the filter with the for loops :when test. No real reason, it just feels more natural to use what for offers since you started with it. Personally, I'd probably use Daniel's filter/take-while solution. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Software developer/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Transforming map entries
On Tue, 22 Feb 2011 15:36:02 -0800 (PST) Daniel Bell dchristianb...@gmail.com wrote: I can't think of anything core, but (let [f #(. % toUpperCase)] (zipmap (keys skills) (map f (vals skills doesn't seem too bad. Does clojure guarantee that keys vals return things in the proper order for this to work? Since it doesn't guarantee that serializing the entries of a map will always get the same order, that seems unlikely. thanks, mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Software developer/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Transforming map entries
On Tue, 22 Feb 2011 16:23:00 -0800 (PST) Alan a...@malloys.org wrote: Yes, it is guaranteed, and I'm dubious about your claim about serializing. (seq foo) will return the entries in foo in the same order always; but (seq (assoc foo 1 2)) may return the entries in a completely different order. You can treat (keys x) as if it were defined by (map key (seq x)): References please? There was a discussion a while back about why maps weren't treated as sequences, the gist of it being that (seq somemap) wasn't guaranteed to always return things in the same order, and requiring an explicit conversion was a reminder of that. Given that, the fact that (keys x) can be treated the same as (map key (seq x)) isn't sufficient to guarantee that (keys x) and (vals x) will return things in the proper order to zipmap them. Given that it was an email discussion, it could well have been wrong - or things could have changed since then. But I'd like to see a reference to that effect, other than the fact that the current implementation behaves that way. Thanks, mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Software developer/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Get digits of a number
On Thu, 17 Feb 2011 10:26:05 -0800 (PST)
JMatt jm...@jmatt.org wrote:
On Feb 16, 10:29 pm, Andreas Kostler
andreas.koestler.le...@gmail.com wrote:
Is there an easy and idiomatic way of getting the digits of a number in
clojure?
Here is my attempt at this from a few months ago:
My turn...
(defn to-digits
Create a seq of digits from a number.
[i]
^{:user/comment For Euler Problems (Specifically 16)}
(map {\0 0 \1 1 \2 2 \3 3 \4 4 \5 5 \6 6 \7 7 \8 8 \9 9}
(str i)))
No assumption about representation here. But my Python background is
showing - Pythons dictionaries are used *everywhere* in the language,
and hence tuned as tightly as possible and thus blasted fast.
mike
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Re: Get digits of a number
On Thu, 17 Feb 2011 15:27:47 -0600
Michael Gardner gardne...@gmail.com wrote:
On Feb 17, 2011, at 1:36 PM, Mike Meyer wrote:
My turn...
(defn to-digits
Create a seq of digits from a number.
[i]
^{:user/comment For Euler Problems (Specifically 16)}
(map {\0 0 \1 1 \2 2 \3 3 \4 4 \5 5 \6 6 \7 7 \8 8 \9 9}
(str i)))
Why not use Character/digit, as Saul suggested?
Because I'm not a java programmer, so my natural inclination is to use
Clojure tools (like the hashmap) rather than Java tools. Since I
hadn't seen a solutions using the hashamp - but had seen some more
complex variants - I thought this one might be of interest.
mike
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Re: 1st script, last hurtle...
On Feb 16, 2:01 am, Michael Sanders bluelamp...@gmail.com wrote: I think I've worked out a better solution (hope this post renders properly): (ns topic (require [clojure.string :as s])) (defn load-block TOPIC database: prints associated blocks to stdout ([tag] (let [STATE (atom 0) rx (re-pattern (str (?i) tag [[:space:]]*(,|$)))] (loop [line (read-line)] (when line (when (and (not= (s/trim line)) (not= \t (subs line 0 1))) (if (re-find rx line) (reset! STATE 1) (reset! STATE 0))) (if (= @STATE 1) (println line)) (recur (read-line))) I think this might be considered a bit more idiomatic to make state a parameter of the loop rather than a mutable variable. ([tag] (let [rx (re-pattern (str (?i) tag [[:space:]]*,(,|$)))] (loop [line (read-line) state 0] (when line (let [new-state (or (when (and (not= (s/trim line)) (not= \t (subs line 0 1))) (if (re-find rx line) 1 0)) state)] (if (= new-state 1) (println line)) (recur (read-line) new-state)) mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Software developer/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Tricky Macro to write.
On Wed, 9 Feb 2011 20:34:56 -0800 (PST) CuppoJava patrickli_2...@hotmail.com wrote: Description: (bind-later bindings body) and (do-binding body) (bind-later) is used like a let-form, except that it doesn't *immediately* make the bindings available. The bindings become available only within (do-binding). (do-binding) is always used within a (bind-later). Here's some sample code showing how it works. (def a outer a) (bind-later (a inner a) (println a)-- this prints out outer a still. (do-binding (println a))) -- this will print out inner a Is such a macro possible? Yes. It's just - as you say - tricky. You need to create a do-binding macro for each bind-later macro, meaning it should be part of the macros lexical space. First trick - use clojure.contrib.macro-utils/macrolet to do that sanely. Then comes the really tricky part - figuring out the correct unquoting for everything. But this does it: (defmacro bind-later [bindings body] `(macrolet [(~'do-binding [ body#] `(let ~'~bindings ~@body#))] ~@body)) Oh, one thing - since let requires a vector for binding, your example has to be written as (bind-later [a inner a] But that's the standard clojure idiom for bindings, so you should do it that way anyway ;-). mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Problems with lazy-xml
On Thu, 10 Feb 2011 07:22:55 -0800 (PST) Marko Topolnik marko.topol...@gmail.com wrote: I am required to process a huge XML file with 300,000 records. The structure is like this: root header /header body record.../record record.../record ... 299,998 more /body /root Obviously, it is of key importance not to allocate memory for all the records at once. I don't think it's obvious. Maybe I'm missing something? Like - how big are the records? If they're less than 1K, that's at most 300 meg in core - which is large, but not impossible on modern hardware. I've been handling .5G data structures in core for the last few years (in Python, anyway). I've run into at least one stupid garbage collector that insisted on scanning such structures even though they weren't changing, which pretty much killed performance. Maybe you have a fast startup requirement, which building the initial data structure would kill. Maybe something else? Thanks, mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Any news on pull requests?
On Thu, 10 Feb 2011 21:57:01 -0800 Sean Corfield seancorfi...@gmail.com wrote: Agreement pretty much identical to the Clojure / Oracle CA (with the only exception to the process being that they will allow scanned, signed CAs to be emailed to the project team). That exception is the major issue, assuming you don't have issues with the terms of the CA. As noted elsewhere in this thread, written CAs are actually pretty common in large, successful open source projects... A far more interesting statistic would be how many of those large, successful open source projects had CAs *before* they were large and successful. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Software developer/SCM consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Any news on pull requests?
On Sat, 5 Feb 2011 20:42:54 -0500 Christopher Petrilli petri...@amber.org wrote: On Sat, Feb 5, 2011 at 1:23 PM, Mike Meyer mwm-keyword-googlegroups.620...@mired.org wrote: On Sat, 5 Feb 2011 00:09:41 -0500 Christopher Petrilli petri...@amber.org wrote: For example, the following projects REQUIRE contributor agreements, in writing, signed and either scanned or on paper, prior to accepting any patches or commits: - Free Software Foundation - Apache, and everything under it - Python I'm sorry, I'm going to call foul on this. I've contributed to Python without ever signing a CA. And the current developers guide page doesn't have anything on it about needing to sign a CA. I do not know when you contributed, or whether it was before this period, but from Certainly possible. My largest contributions were docs, which don't ship with Python and would be excluded. http://wiki.python.org/moin/PythonSoftwareFoundationLicenseFaq: If your code is going to end up in Python or the standard library, the PSF will require you to: * License your code under an acceptable open source license. These currently include only the Academic Free License and the Apache License 2.0, although this list may be expanded in the future. (No, the PSF License is not acceptable; see below) * Fill out and submit a contributor agreement. Perhaps they exclude some small amount of code in the form of patches, but it certainly applies to libraries, etc. You can find the contributor agreement here: http://www.python.org/psf/contrib-form.html It's not that different than the one for Clojure. Again, I'm not arguing whether it's a good thing or not, simply that it's actually not as unheard of as people think, nor is it poorly founded in US legal precedent. I find it odd that they don't mention this on the Developers Guide at http://www.python.org/dev/ or the developers FAQ at http://www.python.org/dev/faq/. Possibly this is a reflection of reality, in that most contributions will be small patches or docs that don't ship, and they don't enforce it until they want to include a library. Or maybe this was planned but never actually happened. I know that it's never been talked about on any of the Python lists I've hung out on. Seriously, the snail-mail requirement is the only one that's really objectionable. Most places are quite happy with a scanned image of the signed document (i.e. - the Chickasaw nation for my citizenship papers). Then perhaps someone can offer to Rich to accept the scanned copies and deal with them? One of the joys of an open source project is not just contributing code, but helping out with the administrative overhead of running a project. Exactly what has to happen to a PDF that was emailed to whoever would have gotten the snail-mail copy, beyond printing and then treating like the snail-mail'ed one? mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Any news on pull requests?
On Sat, 5 Feb 2011 00:09:41 -0500 Christopher Petrilli petri...@amber.org wrote: For example, the following projects REQUIRE contributor agreements, in writing, signed and either scanned or on paper, prior to accepting any patches or commits: - Free Software Foundation - Apache, and everything under it - Python - Perl - Django - MySQL - Node.js - Fedora Linux - Neo4j - Sun (now Oracle) I'm sorry, I'm going to call foul on this. I've contributed to Python without ever signing a CA. And the current developers guide page doesn't have anything on it about needing to sign a CA. Seriously, the snail-mail requirement is the only one that's really objectionable. Most places are quite happy with a scanned image of the signed document (i.e. - the Chickasaw nation for my citizenship papers). Without that requirement, I would already have submitted one. With it? I can submit most fixes/enhancements as patches (my most likely contribution) via the ticketing system without having to jump through that hoop. In the unlikely event I write something significant that someone wants in core or contrib, I'll revisit the issue. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Any news on pull requests?
On Fri, 4 Feb 2011 18:00:24 -0800 Sean Corfield seancorfi...@gmail.com wrote: On Fri, Feb 4, 2011 at 5:24 PM, Eugen Dück eu...@dueck.org wrote: Furthermore, I was really surprised to find on http://clojure.org/contributing that I have to send a (non-e)mail around the world to be able to contribute Written acceptance of a contributor's agreement is fairly common on large open source projects so that there is legal clearance for inclusion of your contribution under the terms of the project license. I find it funny that it takes more paper to sign up as a clojure contributor, which apparently has no benefits to me except bragging rights, than it did to get my Chickasaw Nation citizenship, which has benefits like scholarships, clothing grants for my school-age children, school housing grants, and of course, voting in tribal elections. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Any news on pull requests?
On Fri, 4 Feb 2011 18:36:34 -0800 Sean Corfield seancorfi...@gmail.com wrote: On Fri, Feb 4, 2011 at 6:16 PM, Eugen Dück eu...@dueck.org wrote: Is it really necessary, though? We all agree to EULAs and make other more significant legal commitments online all the time, and in some cases without having proven who and where we are. There are certainly some legal transactions that do not accept electronic agreements and require a physical signature. IANAL so I looked up US copyright law and found this paragraph about transfers in Circular 1 (from here http://www.copyright.gov/help/faq/faq-assignment.html ): Any or all of the copyright owner’s exclusive rights or any subdivision of those rights may be transferred, but the transfer of exclusive rights is not valid unless that transfer is in writing and signed by the owner of the rights conveyed or such owner’s duly authorized agent. Transfer of a right on a nonexclusive basis does not require a written agreement. So that's why a written signature is required for the Clojure CA. Um, read the last line in the quote, about nonexclusive basis. The first bullet of clause two in the CA (downloaded just now) grants Rich Hickey a ... perpetual, irrevocable, non-exclusive, worldwide ... license Given that the license is nonexclusive transfer (and I have to wonder if you'd get any contributors otherwise, or if any other OSS project has an exclusive transfer), then according to that last line, it does not require a written agreement. IANAL either, but it sure seems like the current requirements exceeds what the law requires. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Getting started with Counterclockwise
Ken Wesson kwess...@gmail.com wrote: On Sat, Jan 29, 2011 at 1:46 PM, Mike Meyer mwm-keyword-googlegroups.620...@mired.org wrote: Ditto. Most often, the code site is the sole project site, and everything is there. Some larger projects may have a separate home page, but it's always prominently mentioned on the code site. In either case, the code site is worth checking out - especially if it's the first link turned up by Google. The real problem is that navigating those sites can be a pain, if you aren't intimately familiar with how the project is organized. Ever land at some SourceForge page, see just a brief description of what the project's software is supposed to do and a bunch of SourceForge infrastructure, click files, and encounter a bewildering array of zips and binaries, none clearly labeled as, say, the Windows installer for the current version? Sure, Sturgeon's law is closer to 99% than 90% for the web. But if you don't even look at the right page to start with because of a false assumption, then any suggestions for fixing it are at best futile. -- Sent from my Android tablet with K-9 Mail. Please excuse my brevity. -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Getting started with Counterclockwise
Ken Wesson kwess...@gmail.com wrote: On Sun, Jan 30, 2011 at 12:07 PM, Mike Meyer mwm-keyword-googlegroups.620...@mired.org wrote: Sure, Sturgeon's law is closer to 99% than 90% for the web. But if you don't even look at the right page to start with That is why I say it behooves projects that wish to grow a large user-base to have a highly-ranked google result be clearly the place for prospective end-users to go for further information, documentation, friendly download links, etc. :) Which is exactly what the project page is for most people - if it's the #1 Google result. -- Sent from my Android tablet with K-9 Mail. Please excuse my brevity. -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Getting started with Counterclockwise
Ken Wesson kwess...@gmail.com wrote: On Sun, Jan 30, 2011 at 12:31 PM, Mike Meyer mwm-keyword-googlegroups.620...@mired.org wrote: Ken Wesson kwess...@gmail.com wrote: That is why I say it behooves projects that wish to grow a large user-base to have a highly-ranked google result be clearly the place for prospective end-users to go for further information, documentation, friendly download links, etc. :) Which is exactly what the project page is for most people Disagree. Of course - you're not most people, you're a developer. That means names like bitbucket and sourceforge mean something to you. They don't for people who aren't developers. -- Sent from my Android tablet with K-9 Mail. Please excuse my brevity. -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Getting started with Counterclockwise
On Sun, 30 Jan 2011 13:38:24 -0500 Ken Wesson kwess...@gmail.com wrote: On Sun, Jan 30, 2011 at 1:24 PM, Mike Meyer mwm-keyword-googlegroups.620...@mired.org wrote: Ken Wesson kwess...@gmail.com wrote: On Sun, Jan 30, 2011 at 12:31 PM, Mike Meyer mwm-keyword-googlegroups.620...@mired.org wrote: Ken Wesson kwess...@gmail.com wrote: That is why I say it behooves projects that wish to grow a large user-base to have a highly-ranked google result be clearly the place for prospective end-users to go for further information, documentation, friendly download links, etc. :) Which is exactly what the project page is for most people Disagree. Of course - you're not most people, you're a developer. That means names like bitbucket and sourceforge mean something to you. They don't for people who aren't developers. Not until after they go there once or twice, find confusing project pages with no clear starting point for prospective end users, and form an opinion of the site. :) Yup. Those pages are about as well organized as every other page one finds on the internet, so they wind up forming the exact same opinion as they do of most sites. If someone takes the time to do a good site design, it doesn't matter who hosts it. If they don't, putting it on a custom domain won't magically make it better. For instance, try and figure out how to install the Cyanogenmod software based on www.cyanogenmod.com. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Getting started with Counterclockwise
On Sun, 30 Jan 2011 13:51:40 -0500 Ken Wesson kwess...@gmail.com wrote: On Sun, Jan 30, 2011 at 1:45 PM, Mike Meyer mwm-keyword-googlegroups.620...@mired.org wrote: Not until after they go there once or twice, find confusing project pages with no clear starting point for prospective end users, and form an opinion of the site. :) Yup. Those pages are about as well organized as every other page one finds on the internet, so they wind up forming the exact same opinion as they do of most sites. If someone takes the time to do a good site design, it doesn't matter who hosts it. If they don't, putting it on a custom domain won't magically make it better. For instance, try and figure out how to install the Cyanogenmod software based on www.cyanogenmod.com. But that's neglecting a crucial biasing factor: with project-hosting sites it's very easy to just slap together a few text blurbs for the front page and carry on your business using the tracker and repository; with regular web hosting you need to think a bit and actually come up with some page content, and you probably wouldn't have bothered to get regular web hosting if you weren't intending to. So if there's a regular .com site it's got a higher probability of being easy for end-users to navigate versus a randomly-selected sourceforge page. Disagree, and already provided a counter-example. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Getting started with Counterclockwise
Laurent PETIT laurent.pe...@gmail.com wrote: 2011/1/20 Ken Wesson kwess...@gmail.com On Wed, Jan 19, 2011 at 9:39 AM, Rayne disciplera...@gmail.com wrote: Aren't you a developer? I'm not a CCW developer. If a code.google link is the top of google results, that's what I'm going to click and check out first. code.google is a project hosting site, not just a place to throw up code and developer discussion. Yes, I know, but the general pattern is that those types of project hosting sites tend to host developer-centric material -- that is, material mainly of interest to developers *working on that project*, not just developers *using* it to develop *something else*. Not in my experience. Ditto. Most often, the code site is the sole project site, and everything is there. Some larger projects may have a separate home page, but it's always prominently mentioned on the code site. In either case, the code site is worth checking out - especially if it's the first link turned up by Google. -- Sent from my Android tablet with K-9 Mail. Please excuse my brevity. -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Funding 2011?
On Tue, 4 Jan 2011 09:31:13 -0500 Rich Hickey richhic...@gmail.com wrote: On Nov 28, 2010, at 9:07 PM, Jeremy Dunck wrote: In Dec 2009, Rich asked the community to step up and support core development -- and the community came through. I'm interested in clojure, but not using it professionally yet. I was wondering if funding for 2011 has already been worked out, or if it is an open question? I was going to continue the funding effort, but have decided against it for the reasons given here: http://clojure.org/funding Many thanks to those who participated, That is very sad, but I do understand the problem. Possibly an approach like that taken by FreeBSD - with a foundation that is legally distinct from the core developers - might work for you: http://www.freebsdfoundation.org/about.shtml mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Interesting challenge
On Thu, 30 Dec 2010 12:03:14 -0500 David Nolen dnolen.li...@gmail.com wrote: From the Qi mailing list: http://groups.google.com/group/qilang/browse_thread/thread/e4a2f534fad5032a I contend that this kind of problem cannot be solved (efficiently) in any pure functional programming language. You may disagree Do you know if his C++ version available for examination? thanks, mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Speed of clojure hash map vs java hash map
On Tue, 28 Dec 2010 22:28:54 -0800 Mark Engelberg mark.engelb...@gmail.com wrote: [Standing on soapbox] On Tue, Dec 28, 2010 at 10:15 PM, David Nolen dnolen.li...@gmail.com wrote: Even in in a single threaded context raw insert performance isn't the final word. What if you want to be able to deliver a snapshot for reporting? What if you don't? Seriously, I agree with you that Clojure's data structures have some significant advantages -- if you need those advantages. There are still plenty of apps that use hash tables in a single-threaded manner, or use them in a multithreaded way where contention is unlikely and persistence is unnecessary. In many areas, Clojure has a pay-for-what-you-need philosophy -- this just isn't one of those areas. With respect to data structures, Clojure is very opinionated, with an attitude of Write it with immutable data structures -- you'll thank me later. :) And you'll do that because some things are hard enough that letting the programmer do it themselves - or decide when they need the help - often results in the programmer doing it wrong. I mean - you don't *need* garbage collection for everything: you can allocate and free things by hand, or even use a voluntary garbage collector and mix those two approaches. Historically, those things don't work very well, and most of the world has gone to doing GC by default for everything. There are still cases where you need to free resources by hand, but those tend to be obvious and can either be hooked into the GC system (so you free them just before the GC system frees some containing object) or easy to free properly. Letting programmers lock/unlock shared structures is very similar operation to allocating/freeing data structures, and (from my point of view, anyway) historically hasn't worked very well (I've found dozens of windows/hanging locks/etc. in large systems that had been in *production* for years!). Going to immutable by default for everything is the same as going to gc by default for everything - complete with tools for dealing with the exceptions when they arise. Such systems are still relatively new, and we're still working out the best way to deal with things. Maybe it'll turn out there's some compromise short of what Clojure does that actually works well. But I don't think we'll know what well is unless something tackles doing it full-bore the way clojure does. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Quicksort with accumulator
On Tue, 28 Dec 2010 19:50:28 +0530 Baishampayan Ghose b.gh...@gmail.com wrote: Hello, I tried writing a naive implementation of quicksort using an accumulator. Right now, the code is stack-consuming and returns a stackoverflowerror on large lists. Is there any way to prevent it from consuming stack with some changes? The code is as follows - You don't say what your test data is, but pretty much any quicksort implementation will have some nasty test cases for which its memory usage is nasty and its performance is worse. Given that this is a simple implementation, data that is already sorted is the degenerate case. I don't think you can keep it from using any stack - a non-recursive implementation would just have to maintain it's own stack state. You can do some things to make it use less stack, though. First, deal with sorted data better by picking a median value from coll instead of the first one. Once the sequences get small enough, change to a non-recursive sorting method to sort them. If you're up to serious refactoring, fix the code to generate the partitions inside of qsort*, and then use recur for the tail call of qsort* - and make sure that call is on longer of less and greater. mike (declare qsort qsort* partify) (defn partify [item coll [less equal greater] acc] (if (empty? coll) (qsort* less (concat equal (qsort* greater acc))) (let [[head tail] coll] (cond ( head item) (recur item tail [(cons head less) equal greater] acc) ( head item) (recur item tail [less equal (cons head greater)] acc) :else (recur item tail [less (cons head equal) greater] acc) (defn qsort* [coll acc] (if-let [coll (seq coll)] (partify (first coll) (rest coll) [[] [(first coll)] []] acc) acc)) (defn qsort Perform Quicksort, with apologies to C.A.R. Hoare [coll] (if-let [coll (seq coll)] (qsort* coll []) [])) Regards, BG -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
SCA FAQ link at clojure.org/contributing....
The link to the SCA FAQ on the page at clojure.org/contributing now returns a document not found page. Given that the Clojure CA is based on the Sun Contributor Agreement and what Oracle has since done with NotQuiteSoOpenSolaris, this would seem to be an important document to have available. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Ah-hah! Clojure is a Lisp
On Mon, 20 Dec 2010 19:26:49 +0100 Meikel Brandmeyer m...@kotka.de wrote: Hi, if you prefer text over talk: http://clojure.googlegroups.com/web/AreWeThereYet.pdf Thanks for the link. To bad it made Tufte kill a kitten. I had forgotten there was a textual representation with a lower information density per bit than video. But it does get the ideas across. It seems a lot of this could have come from other applications I'm using these days, like mercurial (with an immutable history) or zfs (with an immutable file system). Thanks again, mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Ah-hah! Clojure is a Lisp
On Mon, 20 Dec 2010 16:27:11 -0500 Ken Wesson kwess...@gmail.com wrote: On Mon, Dec 20, 2010 at 3:00 PM, Mike Meyer mwm-keyword-googlegroups.620...@mired.org wrote: On Mon, 20 Dec 2010 19:26:49 +0100 Meikel Brandmeyer m...@kotka.de wrote: http://clojure.googlegroups.com/web/AreWeThereYet.pdf Thanks for the link. To bad it made Tufte kill a kitten. I had forgotten there was a textual representation with a lower information density per bit than video. Did you mean a higher information density per bit? No, I meant lower. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Ah-hah! Clojure is a Lisp
On Sun, 19 Dec 2010 21:24:42 -0500 Ken Wesson kwess...@gmail.com wrote: On Sun, Dec 19, 2010 at 8:25 PM, Tim Daly d...@axiom-developer.org wrote: On 12/19/2010 8:20 PM, Ken Wesson wrote: On Sun, Dec 19, 2010 at 8:18 PM, Tim Dalyd...@axiom-developer.org wrote: I didn't mean to imply that other people don't have the ah-hah! experience with other languages. However, I have only had the (before lisp)|(after lisp) experience with lisp. Your enlightenment might vary. Rich gave his Whitehead talk and brought up the fact that OO languages get several things wrong. Out of curiosity, which several things were these? http://www.infoq.com/presentations/Are-We-There-Yet-Rich-Hickey Please install Flash Player. Has everyone on this list developed a sudden allergy to plain text and HTML? First I get pointed to a 34-minute video, and now this. A simple bulleted list with a brief precis about each item would have sufficed; a multi-megabyte install of an executable and who knows how much futzing around, overkill. Let me second that - especially since flash isn't available for my normal mail platform, so the kludges required to run it make it even flakier than what Jobs objects to, and tends to hose performance there no end. Yes, somethings may best be presented on video, but all to often people try pass videos off as documentation (*). Even when video is actually the best choice, the least you could do is post something in an actual video format, and not as an executable for a poorly documented, proprietary VM that has had more than one security issue in the past. mike * A video isn't documentation. I can leave documentation open to the relevant page, and search it for the relevant phrases. A video may be educational, but that doesn't make it documentation. -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: about the repl
On Fri, 17 Dec 2010 22:45:01 -0800 (PST) tor torgau...@gmail.com wrote: Is there a way to activate word completion in the repl? I find myself hitting tab all the time... Since nobody else mentioned it (or even offered a solution other than Try my environment), you can use rlwrap (should be available in your systems package manager) to run your repl, and get word completion - among other goodies one wants on a command line. The appropriate rlwrap invocation is: rlwrap --command clojure --complete-filenames --quote-characters='' --prompt-colour=Red followed by whatever command you use to start the repl. You'll also want to past this code into a repl running in your home directory: (def completions (reduce concat (map (fn [ns] (keys (ns-publics ns))) (all-ns (defn save-completions-to [filename] (with-open [f (java.io.BufferedWriter. (java.io.FileWriter. filename))] (.write f (apply str (interleave completions (repeat \n)) (save-completions-to .clojure_completions) to create the list of completions for rlwrap. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Improving the documentation
On Thu, 16 Dec 2010 10:18:47 -0700 Terrance Davis terrance.da...@gmail.com wrote: *begin rant* I have yet to see anyone who posts the classic rtfm (even politely) response search previous posts and realize that rtfm responses have already been sent and refrain from sending the same explanation of how to use a mailing list over and over and over. Simple customer service experience teaches that if customers are asking the same questions multiple times, then the documentation is either, hard to find, incomplete, or not clear enough. Improving the docs is a healthier and more productive use of time than starting yet another thread on how to use a mailing list. *end rant* Sorry. Couldn't contain myself ;-) No need to be sorry - it's a very good point. In the past, I've contributed to open source projects by watching for the same question to be raised multiple times, combining the data in the best answers into one best of breed, and submitting it as a patch for the project handbook. The clojure community doesn't have anything as spiffy as the FreeBSD handbook - instead we have a wiki FAQ page (from clojure.org, click wiki then 2 FAQ to get to http://en.wikibooks.org/wiki/Clojure_Programming). While much more painful than editing docbook, it's a good place to post things. Unfortunately, we can't post excerpts from clojure source there because the wiki license is incompatible with the source license - or anything else using that same license. In particular, not being able to use doc strings, etc. Given that the FAQ itself suggests that such be posted to the clojure group, this makes doing what I did rather problematical. Minimally, I need to figure out whether or not a post contains such an excerpt in order to be able to use it. Worst case, the license for content posted to the group is *also* incompatible with the source license, so you can't legally add any Frequent Answers from there to the FAQ. Ok, I found a problem. Anyone got solutions? mike PS: behavior-modification posts (i.e. - the rtfm posts) needs to be done repeatedly because (we hope) the group keeps growing. If everyone simply ignores improper behavior, the newcomers will assume it's proper behavior (even if there's a covenant for the group saying otherwise). Hence periodic reminders are called for. -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Improving the documentation
On Thu, 16 Dec 2010 17:50:58 -0500 Stuart Halloway stuart.hallo...@gmail.com wrote: On Thu, 16 Dec 2010 10:18:47 -0700 Terrance Davis terrance.da...@gmail.com wrote: *begin rant* I have yet to see anyone who posts the classic rtfm (even politely) response search previous posts and realize that rtfm responses have already been sent and refrain from sending the same explanation of how to use a mailing list over and over and over. Simple customer service experience teaches that if customers are asking the same questions multiple times, then the documentation is either, hard to find, incomplete, or not clear enough. Improving the docs is a healthier and more productive use of time than starting yet another thread on how to use a mailing list. *end rant* Sorry. Couldn't contain myself ;-) No need to be sorry - it's a very good point. In the past, I've contributed to open source projects by watching for the same question to be raised multiple times, combining the data in the best answers into one best of breed, and submitting it as a patch for the project handbook. The clojure community doesn't have anything as spiffy as the FreeBSD handbook - instead we have a wiki FAQ page (from clojure.org, click wiki then 2 FAQ to get to http://en.wikibooks.org/wiki/Clojure_Programming). While much more painful than editing docbook, it's a good place to post things. Unfortunately, we can't post excerpts from clojure source there because the wiki license is incompatible with the source license - or anything else using that same license. In particular, not being able to use doc strings, etc. Given that the FAQ itself suggests that such be posted to the clojure group, this makes doing what I did rather problematical. Minimally, I need to figure out whether or not a post contains such an excerpt in order to be able to use it. Worst case, the license for content posted to the group is *also* incompatible with the source license, so you can't legally add any Frequent Answers from there to the FAQ. Ok, I found a problem. Anyone got solutions? mike The new FAQ (under construction at http://dev.clojure.org/display/doc/FAQ) has edit capabilities tied to signing the CA. If you have signed a CA you can post to the FAQ, quoting from other CA-governed sources (e.g. Clojure) as makes sense. Does that help? First, that looks more like it's part of a wiki aimed at clojure developers than at clojure users. While that's an important thing to have, it's not what I'm looking for, and I'm pretty sure that combining the two is bad idea. Second, a wiki that requires you be a contributor to edit it seems to defeat the point of having a wiki in the first place. If you're going to require someone to be a contribute to edit the docs, why not use a real document processing system instead, so that you can handle documentation using the same tools (source control system, etc.) as you're using for code, and get the added benefit of being able to generate media-specific output (assuming you chose a good dps). Finally, Jira needs a category for wiki bugs so that people who haven't signed a CA can contribute fixes (patches? to a wiki? Another reason to use a real document processing system). mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Clojure 1.3 Alpha 4
On Tue, 14 Dec 2010 21:04:11 -0500 Ken Wesson kwess...@gmail.com wrote: On Tue, Dec 14, 2010 at 8:23 PM, Benny Tsai benny.t...@gmail.com wrote: As Brian said, primitive math is now the default in 1.3. If auto- promotion on overflow is desired, you can use the +', -', *', inc', dec' functions (note the single quote suffix). Why was this done? I preferred having +, -, etc. DTRT in general and unchecked-+, etc. for when you really needed efficient primitive math. My code is littered with + but has few unchecked-+s. Which means I'll have to go through it all adding little tick-marks everywhere and making the math look funny to keep its behavior the same whenever 1.3 is released. One of the things those of us on your side *begged* for (and apparently also didn't get) was that the versions with correct behavior not have second-class names. That we didn't get them means we'll have to provide them ourselves, but it's easy. Since we're having to fix code anyway, just use a file containing something like: (def add +') (def sub -') (def mul *') (def add1 inc') (def sub1 dec') when you need it. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Clojure 1.3 Alpha 4
On Wed, 15 Dec 2010 13:02:13 -0500 Ken Wesson kwess...@gmail.com wrote: On Wed, Dec 15, 2010 at 12:51 PM, Eric Schulte schulte.e...@gmail.com wrote: Ken Wesson kwess...@gmail.com writes: Are you honestly suggesting I search the archives It is common courtesy on open-source lists such as this one to check if a question you are about to ask has already been answered. As I believe I already mentioned, if everyone spends a while searching some archives every time they are going to post, this list's traffic will drop to nearly nil. Do we really want that? Actually, what would drop to nearly nil would be questions that have already been answered and points that have already been debated to death. And yes, we *do* want that. In fact, it's part of the FAQ on asking smart questions: http://www.catb.org/~esr/faqs/smart-questions.html. Further, not only is it easy (the list is hosted by google groups, so just googling for keywords will search it) but may well turn up the answer faster than posting to the list. Admittedly, that (or searching the archives proper) might not have found what you're looking for in this case, because neither enhanced nor primitive leap to mind as search terms when you get an unexpected overflow error. But it works often enough that checking google before asking a question is a productive habit to get into. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Clojure 1.3 Alpha 4
Vagif Verdi vagif.ve...@gmail.com wrote: Maybe clojure should adopt linux versioning scheme, where even numbers are stable production clojure and odd numbers are development branch ? Gods please no. -- Sent from my Android phone with K-9 Mail. Please excuse my brevity. -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Moderately off-topic: installing emacs on OSX
On Sat, 11 Dec 2010 01:07:51 + Alec Battles alec.batt...@gmail.com wrote: I don't use OS X so I can't comment on such a consensus, but while I appreciate the sentiment, it's actually harmful to some degree to have lots of blog posts scattered around everywhere that all have slightly different advice, especially since that advice usually becomes outdated within the year. Speak for yourself. Whenever I need to install SCIM on someone's computer I pull up three conflicting blog posts and just combine elements of all of them. I do that as well. And then, after a couple of days trying all the various combinations and having none of them work, I give up and ask the on the list to get an answer that actually works with the current versions of all the tools. Of course, if a typical howto was more than a recipe of steps with no explanations, but actually documented why you wanted to take each step and what it achieved, then you might have a chance of figuring out how to mix them to be right for your environment. I strongly suggest improving the docs on the Clojure wiki instead; that way errors can be fixed by the community. Why does the one preclude the other? Much as I hate wiki's, an up-to-date wiki is *much* better than a collection of out of date blog entries. It makes the reading the out-of-date blog entries that google returns a waste of time. If the wiki isn't up to date, then it just becomes a part of the trial-and-error process that's the norm for getting things done in the Linux world. Also, if people aren't going to blog about Clojure, what future does it have? If people can't figure out how to get Clojure installed because all they can find on the web is out of date blog entries, what future does it have? There's *lots* of good thing in clojure to blog about without writing yet another howto that's going to be out of date in a few months. You can write about what you're doing with it: how the Java interop helps with that, how the nifty data structures and functions that work with them assist the process of creating a program, etc. Basically, it's a simple choice - do you help yourself by writing an entry for your blog, or do you help the clojure community by writing an entry for the wiki? I claim the subject matter should determine which: if you're documenting how to use clojure, put it on the wiki. If you're documenting how you're using clojure, put it in your blog. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Lots of newbie clojure questions
On Tue, 7 Dec 2010 02:58:11 -0500 Ken Wesson kwess...@gmail.com wrote: On Tue, Dec 7, 2010 at 2:15 AM, javajosh javaj...@gmail.com wrote: Mike and I have had a nice off-line conversation where we enumerated the possible things that can come after open-parens. I listed 7, he added 3: That wasn't meant to be offline, but it's probably not worth resending. However... 1. A value (if the paren has a tick '( ) 2. A function. 3. A map - which is a psuedo function that takes a key as an arg. 4. A keyword - which is a psuedo function that takes a map as an arg. 5. A macro. This is the normal case, I think. Looking through the mailing list, it appears that most clojure programming questions revolve around which one of the hundreds of macros to invoke and in which order! 6. The Java form: (MyClass. ) 7. The java method form (.doSomething) 8. A function returning a function to invoke - ((find-my-function) ) 9. A loop - (recur ) 10. The anonymous function macro: #( ) So, at least I know why I feel uneasy about open paren! It's super overloaded. Not really. (...) is a non-atomic s-expression. If it's evaluated unquoted, the first nested s-expression is evaluated and if it's not callable an exception is thrown. Macros, special forms (which are sort of like system-internal macros and are used to build all the other macros, and functions), Java constructors, Java methods, and functions are callable (and maps and keywords -- also vectors -- act as functions for this purpose). The only real overloading always involves macros: #() evaluates to a function and doesn't run its insides right away. Then again so does (defn foo [x] (inc x)) -- the (inc x) is run when foo is called, calling inc, but not when the (defn ...) is called. Macros can delay evaluation of their contents, and #() is a reader macro. '(x y z) is another reader macro and expands to (quote (x y z)). This was pretty much what I tried to explain as well, even including the comment that I almost never used '( ) in clojure because vectors worked as well. Mike also points out that things that aren't functions (not used in that context) can't be aliased with def or use. Really? user= (def a 3) #'user/a user= (def b a) #'user/b user= b 3 This one I flubbed, because my vocabulary failed me. There are three classes of values that can work when they show up in the first position in an executable expression: 1) Functions, which can also be passed to higher order functions. 2) Macros, which can't, but can be aliased by def or use. 3) Java interop things (#6 6 7 on his list), which can't be aliased by def or use. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: parameters destructuring sets?
On Mon, 6 Dec 2010 16:30:10 -0500 Ken Wesson kwess...@gmail.com wrote: On Mon, Dec 6, 2010 at 1:05 PM, Stuart Sierra the.stuart.sie...@gmail.com wrote: On Dec 6, 8:36 am, Ken Wesson kwess...@gmail.com wrote: Furthermore, the comment (not made by Hickey) that map order may be unstable is more than a little puzzling in light of the fact that the maps in question are immutable. :) In general, Rich has been careful not to promise things that might limit changes he can make in the future. Sets and maps are unordered. `seq` happens to be deterministic on ArrayMap and HashMap, but there might some day be some other kind of map or set for which `seq` cannot be deterministic. Therefore, Clojure does not promise anything about `seq` on maps, other than that it will return the key-value pairs. I confess I can't see any obvious reason ever to make seq nondeterministic on an immutable data structure. I suspect you're applying immutable to everything about the data structure, whereas it can also be applied the value without including the implementation. I can see wanting to change the implementation in ways that don't change the value - triggered by something like wanting to share parts of the value with another structure, or a garbage collection, or ... - which could easily change the results of calling seq on the structure. Not that I know that anything in clojure does that, just that I can see conditions where you might want to. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: parameters destructuring sets?
On Mon, 6 Dec 2010 17:07:15 -0500
Ken Wesson kwess...@gmail.com wrote:
On Mon, Dec 6, 2010 at 4:44 PM, Mike Meyer
mwm-keyword-googlegroups.620...@mired.org wrote:
On Mon, 6 Dec 2010 16:30:10 -0500
Ken Wesson kwess...@gmail.com wrote:
On Mon, Dec 6, 2010 at 1:05 PM, Stuart Sierra
the.stuart.sie...@gmail.com wrote:
On Dec 6, 8:36 am, Ken Wesson kwess...@gmail.com wrote:
Furthermore, the comment (not made by Hickey) that map order may be
unstable is more than a little puzzling in light of the fact that the
maps in question are immutable. :)
In general, Rich has been careful not to promise things that might
limit changes he can make in the future. Sets and maps are unordered.
`seq` happens to be deterministic on ArrayMap and HashMap, but there
might some day be some other kind of map or set for which `seq` cannot
be deterministic. Therefore, Clojure does not promise anything about
`seq` on maps, other than that it will return the key-value pairs.
I confess I can't see any obvious reason ever to make seq
nondeterministic on an immutable data structure.
I suspect you're applying immutable to everything about the data
structure, whereas it can also be applied the value without including
the implementation. I can see wanting to change the implementation in
ways that don't change the value - triggered by something like wanting
to share parts of the value with another structure, or a garbage
collection, or ... - which could easily change the results of calling
seq on the structure.
Perhaps. But under those circumstances seq itself has the same problem
you're using to excuse not supporting nth, yet seq is supported.
I had some trouble figuring out what you're saying here, so let me
know if I got this wrong: I'm providing reasons for seq to not have a
guarantee of determinism when called on some structures, and that
non-determinism is the justification for nth not being supported, so
why is seq supported?
A non-deterministic nth has no value - you might as well just use
first (and in fact, you can). A non-deterministic seq, on the other
hand, *does* have a value: it provides representation of the value for
which nth (and friends) have a deterministic value.
Having nth call seq on structures for which seq is non-deterministic
would slow down nth, and possibly hide buggy code. Forcing the call to
seq be explicit means there's a chance they'll notice the
non-deterministic result, and fix the bug.
And so is (nth (seq x)) on these things; if the implementation
changed its innards while you were walking the seq (even with map!
Nevermind using nth) this could trip up. You might have a set #{1 2
3 4 5 6} and seq would produce (1 3 4 5 2 6) and then someone makes
another set from it with disj and the structure rearranges, so seq
would now produce (1 5 6 2 4 3). Meanwhile, another thread has
produced a seq and is traversing it at the time and gets (1 3 4 2 4
3). Oops.
There are a number of ways to avoid this bug. You found at least one
of them here:
If that kind of internal rearrangement is to be done, seq will have to
copy the structure's contents (by realizing the seq promptly; so there
goes laziness) in order to avoid that kind of error. And once you have
that, you will want to create AND CACHE the (immutable!) structure's
seq-representation when it's first needed. And you can do so when nth
is called, as well as seq. And then due to the caching both nth and
seq will obey (if (identical? s1 s2) (identical? (f s1) (f s2))) when
substituted for f.
Even then, I'd expect internal rearrangement to be a thread-safety
nightmare; in all likelihood a) rearranging operations, and b)
operations like realizing the seq that will be b0rked by concurrent
rearrangements, will require locking the structure. Locking is
supposed to be kept to a minimum as one of Clojure's design goals,
IIRC.
This gets worse when you note that seq realization can cause the
execution of user-supplied code (e.g. the body of a lazy-seq macro)
during realization. If user-supplied code can end up executing with
user-invisible monitors locked, and can in turn cause more monitors to
be locked (say, by disjing a set thus causing one of your hypothetical
internal rearrangements), then it can cause deadlocks that would be
fiendishly difficult to track down and fix. And deadlock avoidance is
*emphatically* one of Clojure's design goals.
All true. As far as I'm concerned, it's also all irrelevant. Just
because doing a thing is hard in all known examples doesn't mean you
want to give up the right to do it should you decide you need to.
mike
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Re: Lots of newbie clojure questions
On Mon, 6 Dec 2010 16:50:40 -0800 (PST) javajosh javaj...@gmail.com wrote: 1. What is the justification for using a map as a function? I find this to be very confusing. The same as using a keyword for a function - it lets you write shorter code. 2. In practice, I find myself wincing when needing to decide whether or not to type an open-paren. Is that a common thing? I don't believe so. Hopefully it will go away soon. 3. Is there a compendium of recursive idioms, ideally expressed in clojure? Including indentation conventions! (Is there an opportunity for a python inspired pre-processor that interprets indentation as parens?) Well, I've always liked D.W. Barron's Recursive Techniques in Programming, and found Eric S. Robert's Thinking Recursively to be worth reading, but neither are in LISP. On the other hand, I'm not sure that a LISP programmer would see the value in a compendium of recursive idioms. 4. Why don't long-running clojure programs monotonically increase in heap usage if all data-structures are immutable? For the same reason that Java programs don't monotonically increase in heap usage: the Java garbage collector recycles storage that's no longer in use. 5. In the REPL, isn't it redundant to always have to type the top- level parens? Not really. If you don't do that, the REPL has to figure out what a naked token on the command line is, and then decide whether or not to add the parens to it. That said, what you're asking about has been used in various LISP systems dating back to the last century, and is known as an evalquote REPL (as opposed to the more common eval REPL used by Clojure). There are a number of CL implementations floating around the web, but I haven't seen one for clojure. 6. Is there a place to get guidlines on macro idioms? The feature is so powerful that it seems like it would be easy to misuse it and crack a programmers head like a nut with a badly structured macro. Halloway's Programming Clojure has a good chapter on macros, but it's not as comprehensive as a good CL book's coverage (ask if you want references, but I wouldn't recommend learning CL just to help with clojure). In particular, he doesn't talk about using macros as an optimization technique. It does give a good set of rules for writing macros: 1) Don't write macros. 2) Only write macros if that's the only way to encapsulate a pattern. 3) You can write a macro if it makes life easier for your callers than the equivalent function (my aside: write the function, then have the macro invoke it). I also have some philosophical questions: Given that I have to live in the poor physical approximation to the real world described by mathematics, I'm going to skip most of these. 1. Isn't the world actually imperative? And mutable? Collaboration *is* a messy proposition in real life. It's hard to fix your car, and even harder to have lots of people fix your car. I find the it models the real world better justification for functional programming rather confusing. (Indeed, the CPU and physical memory also have an imperative relationship!) 2. 'Side-effects' are treated almost as a bad word by most functional programming advocates. And yet, aren't ALL programs executed for their side-effects? Does side effect perhaps then require a qualification or a tighter definition? Or perhaps side-effects aren't that bad? 3. What is the relationship between the shape of a clojure program and the runtime call stack? (I ask because a clojure program looks strikingly similar to the callstack of an ordinary program when you 'pause' a thread.) 4. Is it possible (and/or advisable) to introduce a typing system on top of clojure? E.g. a macro-form along the lines of (fnif type_function function args) mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: How can I avoid needing this other function?
On Tue, 7 Dec 2010 00:44:52 -0500
Alex Baranosky alexander.barano...@gmail.com wrote:
Here is the code I'm working on. The first function is wanted. The second
is not. (and the duplication is waiting to be factored out somehow...)
Is there an idiomatic Clojure way to use map-of-distances on the Line of
Note below, instead of map-of-distances* ?
Thanks for all your help.
(defn map-of-distances [origin locations]
(loop [dists {} locs locations]
(if (seq locs)
(let [[loc more] locs
dist (dist-in-miles origin loc)
dists (assoc dists loc dist)]
(recur dists more))
dists)))
(defn map-of-distances* [origin locations]
(loop [dists {} locs locations]
(if (seq locs)
(let [[loc more] locs
dist (dist-in-miles origin loc)
dists (assoc dists loc dist)]
(recur dists more))
dists)))
(defn relative-distance
Gives distance * frequency.
frequencies are in days out of 365
[origin locations-n-frequencies]
(let [loc-w-dists (map-of-distances* origin (take-nth 2
locations-n-frequencies)) ; -- Line of Note
loc-w-freqs (apply hash-map locations-n-frequencies)]
(multi-fmap (fn [d f] (* d f)) loc-w-dists loc-w-freqs)))
I haven't verified it, but based on the two interfaces, you want to
use apply again:
(map-of-distances* origin (take-nth 2 locations-n-frequencies))
can be written as:
(apply map-of-distances origin (take-nth 2 locations-n-frequencies))
FWIW, if you really needed them both, it'd be idiomatic to write one
in terms of the other:
(defn map-of-distances [origin locations]
(map-of-distances* origin locations))
or (going the other way):
(defn map-of-distances* [origin locations]
(apply map-of-distances origin locations))
though this one you might not bother to write out, and just use the
apply inline as above.
mike
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Ring startup processing?
My simple web app (http://blog.mired.org/2010/11/x10-controller-in-clojure.html) has some stuff that needs to happen just once (in this case, opening the serial port). It's not clear how to get this to happen using ring. If I do it inside my ring handler, then it gets run on every request, and I have to check to make sure it's not run multiple times. If I run it outside the handler, then it gets run when I do lein uberwar, which is simply wrong. When the deployment platform activates the war would seem to be the right time to run this (war load time?). So maybe this is a question that depends on the deployment platform, or war? However, a quick google search didn't turn up anything that looked interesting. Anyone got suggestions on how to set up code to be run when Jetty (or tomcat, or ...)? thanks, mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: discussing Clojure with non-CS types
of thing, but it doesn't seem quite as mature - and I believe it runs at JVM speeds.) 8. Every problem has been solved twice in Java. Meaning it has been solved three times in clojure. Java's a relative newcomer. If it's been solved twice in Java, it's probably been solved twice in Python, with wrapped C and C++ solutions available as well. This is not always a good thing... The underlying theme is that you can quickly write the code that you need to do your job, so that you can get back to doing your job. At this stage, I suspect that Python is still the better tool for them. The advantages Clojure has over Python are in the for computer scientists domain, whereas Python's advantages over Clojure are things that will matter to them: access to libraries they are familiar with, and that it's much easier to read Python code on first exposure, means that sharing results (an important part of the process) is much easier. Especially since there's a community of people willing to help them with it at http://www.scipy.org/. Of course, if you're trying to get them off FORTRAN, pretty much anything would be an improvement. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Question about an idiom.....
On Wed, 24 Nov 2010 00:37:07 -0800 (PST)
LauJensen lau.jen...@bestinclass.dk wrote:
You just touched on an idiom I see fairly often here that bugs me. I'm
not intentionally singling you - or CQL! - out for this, but you made
a comment that sets up my question perfectly.
(let [photo-counts (- (table :photos)
(aggregate [[:count/* :as :cnt]] [:id])))]
(- (table :users)
(join photo-counts (= {:users.id :photos.id}))
I think thats really as simple as you can express that join operation.
Um, I can see two macros that, if expanded in place, would result in a
simpler expression (assuming that CQL doesn't redefine -):
(let [photo-counts (aggregate (table :photos) [[:count/* :as :cnt]] [:id])]
(join (table :users) photo-counts (= {:users.id :photos.id})))
I also fixed the parens - I think. I removed one after [:id], and it
seems like two were missing at the end as well.
Ok, I understand why you would use - if you're threading through
multiple forms. I don't know that I like it, but I can at least
understand it. But when it's only one form? In the best case - when
the form is a symbol, as in (- 1 inc) - it just wastes three
characters to reverse the form and argument. More often - for example
(- 1 (+ 2)) - it also adds another level of parenthesis, which I
thought most people considered a hindrance to comprehension.
Could someone explain where this urge to write (- expr (func arg))
instead of (func expr arg) comes from?
mike
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Re: Question about an idiom.....
On Wed, 24 Nov 2010 22:51:09 +0100 Daniel Werner daniel.d.wer...@googlemail.com wrote: On 24 November 2010 21:40, Mike Meyer mwm-keyword-googlegroups.620...@mired.org wrote: Could someone explain where this urge to write (- expr (func arg)) instead of (func expr arg) comes from? I like to use - and - because they allow me to add more steps to the pipeline as needed, without requiring ever more deeply nested parentheses. Of course, the examples you cited were intentionally trivial Those cases weren't intentionally trivial, they were the point. What's the motive for using - when there's only one form after the expression? I get why you'd do it with two or more forms - it reduces the nesting, and reading left-to right follows the evaluation order. But with just one form it's liable to have the opposite effect on nesting, and it makes the evaluation order read zig-zag. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Clojure vs Clisp...How big is the difference??
On Sun, 21 Nov 2010 16:26:07 -0800 (PST) coco clasesparticulares...@gmail.com wrote: Hi everybody...I'm interested in learning clojure but there're only a few books and more focused to advanced programmers...I found today a nice book about Clisp but I don't know how different is itplease can tell if can be recommendable learn first Clisp with a easy follow book..or if there are many differences about these and It's not recommendable Well, learning Clisp first will make learning Clojure a lot easier if you're not familiar with LISPs or functional programming. However, Clisp is large enough that you could easily spend more time there than you saved. If you really want to tackle a more established language before Clojure, I'd recommend Scheme instead, partly because Scheme is nice and small, but mostly because it also has some really good books available. On the other hand, there are some good Clojure books, and I'm tempted to say just start with those, but I haven't had the opportunity to use them to learn functional programming, so I'm not sure how much that opinion is worth. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Weird result for (get max key)
On Fri, 19 Nov 2010 17:52:03 -0800 (PST) Bob Shock shock...@gmail.com wrote: I had a bug in my code where I meant to type: (get map key) and instead typed: (get max key) It seems that any function name I put in for max always returns nil. user= (get max 3) nil user= (get min 3) nil user= (get maxx 3) java.lang.Exception: Unable to resolve symbol: maxx in this context (NO_SOURCE_FILE:10) user= Any ideas? Yup. get returns nil if the key isn't in the map. Since functions aren't maps (or anything else that fits that abstraction), they can't contain the key, so you get nil. If you try it with pretty much any arbitrary map value (integers, etc.) you get nil. If you provide the third argument to get, you'll get that value back in all these cases. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Incorrect behaviour for large s-expressions :(
On Sun, 14 Nov 2010 00:48:13 -0500 Robert McIntyre r...@mit.edu wrote: So my friend and I were screwing around, battling versions of LISP as nerds are wont to do, when I came across this: (eval `(clojure.core/+ ~@(take 1e4 (iterate inc 1 Invalid method Code length 89884 in class file user$eval13607 This is just trying to evaluate + directly on a bunch of arguments. I'd say the first problem is using the macro-building constructs outside a macro. I believe this is generally a bad idea. If you build the list and apply + to it directly, it works fine Clojure 1.2.0 user= (apply + (doall (take 1e4 (iterate inc 1 (apply + (take 1e4 (iterate inc 1))) 50005000 user= (apply + (doall (take 1e5 (iterate inc 1 (apply + (take 1e5 (iterate inc 1))) 55 user= But nope, you've got a real problem. It appears to be with eval: user= (eval (cons + (take 1e4 (iterate inc 1 (eval (cons + (take 1e4 (iterate inc 1 java.lang.ClassFormatError: Invalid method Code length 89881 in class file user$eval26 (NO_SOURCE_FILE:8) user= (count (cons + (take 1e4 (iterate inc 1 (count (cons + (take 1e4 (iterate inc 1 10001 Of course, eval isn't idiomatic clojure. Common Lisp on my friend's 30 year old Lisp machine does the equivalent of this with ease, even for much larger numbers. As I'm writing this, my friend is rubbing in this in my face by also doing the above with C-LISP on his laptop. (although his stack overflows for 1e5) Well, the apply version works out to 1e8 for me if I leave out the doall. If I use the doall, it runs out of heap at 1e7. I'm a little surprised that they're different - I figured apply would instantiate the sequence, and I'd need to use reduce instead of apply for really large sequences. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Incorrect behaviour for large s-expressions :(
On Sun, 14 Nov 2010 08:43:11 -0500 Robert McIntyre r...@mit.edu wrote: @Mike Meyer Using apply is different than what I'm doing. Yup. When I use eval I'm trying to evaluate a huge s-expression. When you use apply you're evaluating a s-expression with three elements. Same thing with the count form (except with two elements). The problem isn't because I'm calling eval or not using idiomatic clojure; I just wrote it that way so it would only take one line. I did agree that there was a problem. The thing is, quasiquotes in clojure were designed for use in macros, and using them outside macros sometimes generates weird results: I wanted to make sure that wasn't the case here. My first attempt - in idiomatic clojure - didn't recreate it. So I went a bit further afield to do so. Are we really OK with having a 30 year old (Common Lisp/Lisp Machine) that operates at megahertz speeds do better than (clojure/JVM) here? Yes, I'm OK that a LISP running on an architecture that's the end result of decades of research on creating machines that run LISP well has fewer and/or higher limits than a LISP running on a VM designed to run Java. I'm not even sure it's worth any effort in fixing. You're not going to run into this limit except in machine-generated code, and there's an easy work-around: generate (apply fun (sequence)) instead of (fun sequence). mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Clojure vs. serial ports
I'm working on a clojure web app that manipulates the serial port. Well, uses it, anyway. The basic structure is to create a map from web-visible names to devices accessible via the serial ports. The problem is that Clojure and the serial port drivers don't seem to get along very well. I'm using the RXTX package (with class names in the gnu.io. hierarchy). If I open the serial port as part of building up my maps, everything works fine in testing, but trying to compile the uberwar hangs. If I wrap the port opening and connection calls in a delay and then force them when I actually need to use it, the first call fails to do anything - seems like the .open returns before the port is actually ready. Similarly, if I restructure things to open the port before use and close it afterward, nothing ever happens at all. It's been a while since I tried this, and I thought at the time the problem was that I was closing the port to soon; but looking at it now I see that the open may be failing. When I try running multiple actions through the port in a loop, only the first one actually happens. Yes, I realize only the first of these is really related to Clojure per se, but figured I'd put them all out on the chance that anyone who could help with the first one is probably familiar enough with the RXTX or serial port IO in Java to help with all of them. Thanks, mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: could clojure be androids joker card
On Sun, 7 Nov 2010 12:42:09 +0100 Jacek Laskowski ja...@laskowski.net.pl wrote: On Sun, Nov 7, 2010 at 10:10 AM, Santosh Rajan santra...@gmail.com wrote: I would really like to see Clojure work on android the same way. Hi, I can hardly explain it myself and that's why I'm asking others whenever I stumble upon such a statement. Bear with my ignorance. I'm simply curious. Why is that important to you? I believe you can use Clojure as a Java library right now without much worries, can't you? Is merely Clojure's syntax so appealing? No, its more having a REPL available, so that you can: 1) It makes a nice programmable calculator for mobile devices. 2) I can test out an idea when I have it, rather than having to make a note of it and test it when I'm back at my desk. 3) I can answer mail asking questions about clojure and provided checked answers while on the go, rather than wait until I'm back at my desk. 4) I can do development on all aspects of a clojure application that's going to run on android on the device. And of course: 5) Java is that unappealing. Admittedly, there are other good solutions for some of these, and others you'd only want to do under extreme conditions - or with an android tablet - but still, they do add up. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: From jetty to war?
On Fri, 5 Nov 2010 13:42:44 -0700 Sean Corfield seancorfi...@gmail.com wrote: On Fri, Nov 5, 2010 at 12:41 PM, Michael Ossareh ossa...@gmail.com wrote: I've regularly found that the multi-disciplinarian programmer is far more adept at solving issues in a creative manner than the I've a skilled hammer and I'll wield it in the direction of any nail-mono-linguistic programmer. Perhaps that is just an artifact of working in startups though. Possibly. His comment is generally true, at least so long as the languages are really different. The obvious solution in one language may be non-obvious in a second, but have advantages over the obvious solution in the second language. A programmer skilled in both languages is more likely to see that creative solution than one who only knows the second language. I've worked in a variety of organizations from small startups to large corporations (such as insurance companies). In the smaller companies, developers have to wear more hats and it's common for a web developer to know HTML, JavaScript, SQL, **insert scripting language** and often shell scripts and / or other tools to help automate tasks. I don't see much difference between that and **insert multiple languages**. This affect only works if the languages are sufficiently different to have different obvious solutions for a large number of problems. This is why people recommend learning a LISP even if you'll never use it - it will expand the way you look at problems. In your case, you have a markup language instead of a programming language, a database language, and a handful of scripting languages. Depending on the scripting languages, that's more like an expert in C++, C# and Java - basically three iterations of the same language - than an expert in (for example) C, Python, and Scheme. When it comes to multi-language projects, if you project is all Python, then someone who knows C/Python/Scheme and someone who knows Java/Python/Clojure are probably equivalent candidates. If your project is Java/Python, then the second one would be a good fit, and the first somewhat questionable (at the very least, they'll need time to come up to speed on Java). So even if you restrict yourself to multilingual programmers, multiple implementation languages cuts down on the pool of qualified people. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Some questions about Clojure Protocols
On Thu, 4 Nov 2010 00:50:35 -0700 Paul Hobbs paul_ho...@hmc.edu wrote: Strong type systems make programming in the large easier. Paul, Strong typing has so many definitions that your statement is nearly meaningless. See http://www.wordiq.com/definition/Strong_typing for a few. Now, if you have some prove that's not just anecdotal, I'd be interested in hearing. Likewise if someone has prove of the contrary. Thanks, mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Python is way faster than Clojure on this task
On Thu, 4 Nov 2010 22:28:12 +0100 Pepijn de Vos pepijnde...@gmail.com wrote: Hi all, I have written a Python script to analyze Minecraft levels and render a graph. Then I did the same with Clojure. It takes Python 10 seconds to analyze a map, while it takes Clojure over a minute. After having tried different options without any significant improvement, I am lost as to why there is such a huge difference. I wouldn't mind an extra pair of eyes/brains to look at this. I blogged about it in more detail here: http://pepijndevos.nl/clojure-versus-python Clojure version: https://github.com/pepijndevos/Clomian/ Python version: https://github.com/l0b0/mian Clojure spends most of its time in the freqs function, here are a couple of variations: https://gist.github.com/663096 If you want to run the code yourself, you'll need a Minecraft level and JNBT, which is not on Maven. JNBT: http://jnbt.sourceforge.net/ The level used in the blogpost: http://dl.dropbox.com/u/10094764/World2.zip Can you check GC activity in the clojure version? I once ran into an issue where Python was running rings around an Eiffel version (compiled down to native code - no VM need apply). This looks similar to what you have, in that I built a large data structure, and then started groveling over it. Turned out that Eiffel was doing a mark-and-sweep GC, which was spending all of it's time marking and sweeping the large static data structure, whereas python doing a reference count GC didn't. Given that I know nothing about Java GCs, this is just a WAG. Come to think of it, how about trying to run the program Jython? That should have the same GC issues. If it's some similar environmental problem, that would show up there as well. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Polymorphic protocols and containers....
It seems like the polymorphism of protocols breaks inside the methods. This is a problem for having a function that's polymorphic between an object and a container of the same objects. For instance: user= (defprotocol Tune (tweek [this])) Tune user= (deftype Knob [name] Tune (tweek [this] (println Tweeked name))) user.Knob user= (def base (Knob. base)) #'user/base user= (tweek base) Tweeked base nil user= (def treble (Knob. treble)) #'user/treble user= (tweek treble) Tweeked treble nil user= (deftype Box [ knobs] Tune (tweek [this] (for [knob knobs] (tweek knob user.Box user= (tweek (Box. base treble)) user= (tweek (Box. base treble)) java.lang.IllegalArgumentException: Don't know how to create ISeq from: user.Knob (user= Where what I really want to happen is to tweek all the knobs in the box. Unfortunately, tweek inside the method seems to be wired to the method it's in, and no longer polymorphic. I've tried various ways to get to the variable I want, and some hinting, but nothing seems to change what I'm getting here. Maybe I shouldn't be trying to use protocols and types for this? Can someone let me know what I need to do to make this happen? Thanks, mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: From jetty to war?
Sean Corfield seancorfi...@gmail.com wrote .. Why are folks so insistent on monolingual systems? We're facing that now, and with a mono-lingual system, you know everyone can contribute to any part of the project. If different parts are in different languages, then people working in one area won't necessarily be able to help with other parts should they need the help. Of course, what you're calling insistent is just people wanting to the frameworks to exist so they *can* do that, not really insisting that some current system be monolingual in spite of that lack. Even the above (admittedly minor) advantage to monolingual systems is enough to justify wanting those frameworks even while you're building multilingual systems. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: From jetty to war?
On Wed, 3 Nov 2010 16:26:13 -0700 Sean Corfield seancorfi...@gmail.com wrote: On Wed, Nov 3, 2010 at 3:31 PM, Mike Meyer mwm-keyword-googlegroups.620...@mired.org wrote: We're facing that now, and with a mono-lingual system, you know everyone can contribute to any part of the project. If different parts are in different languages, then people working in one area won't necessarily be able to help with other parts should they need the help. Solution: don't have monolingual programmers on your team :) What, we shouldn't hire Americans? :-) That only helps if everyone actually knows all the languages involved (we're looking at Ruby, Python and I'm trying to make a case for Clojure - but the critical language for my part of it is going to be XPath and/or XQuery). Finding good people is hard enough that wanting them to be good in three or four languages is enough to break the camels back. If you've got time to cross-train them - then you don't need I do understand the forces at play here. I've worked with a lot of monolingual teams and seen these same discussions about wishing we had framework X from language Y. I just cringe at the work invested in recreating all these frameworks in so many languages - especially when we're (nearly) all on the same JVM and we _could_ leverage these other languages / frameworks as-is. It just seems like so much wasted effort Except (in least in this case) some of the languages aren't on the JVM. In fact, I'm starting to get pressure against Jython and Clojure because of the legal mess that's starting to embroil the Java world. Way off topic, but anyone got any advice on *that*? mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: A question regarding map destructuring
On Mon, 1 Nov 2010 23:41:47 -0700 (PDT)
Meikel Brandmeyer m...@kotka.de wrote:
Hi,
On 2 Nov., 03:25, Mike K mbk.li...@gmail.com wrote:
(print-value-a [:b 7 :a 3])
; actually prints nil
You have to use apply. (apply print-value-a [:b 7 :a 3]).
Furthermore: how could (let [{a :a} [:b 7 :a 3]] [a]) possibly work?
The same way this one works:
(defn foo [ {:keys [a b]}] ...)
is equivalent to
(defn foo [ options#] (let [{:keys [a b]} (apply hash-map
options#)] ...))
This only happens if the rest argument destructuring is a hash map -
if I use a vector or a symbol there, then the values don't get turned
into a map. Can't that same mechanism be used in the case where some
non-rest argument is a hash-map trying to destructure a sequence?
So that:
(let [{a :a} [:b 7 :a 3]] ...)
would be equivalent to
(let [x# [:b 7 :a 3]] (let [{a :a} (apply hash-map x#)] ...)
user= (let [{a :a} [:b 7 :a 3]] [a])
[nil]
user= (let [{a 2} [:b 7 :a 3]] [a])
[:a]
The map destructuring in the defn is a special case of defn, not
destructuring itself.
Interesting. This means you can't use your second example to
destructure a rest argument:
user= ((fn [ {a 2}] [a]) :b 7 :a 3)
[nil]
But that's the same behavior as you got with 1.1. But this case:
user= ((fn [ {a 2}] [a]) 1 7 2 3)
[3] ;; 1.2 behavior; 1.1 returns [nil]
Changed between 1.1 and 1.2.
As much as I hate special cases when they aren't needed, I'm not
arguing that this should change. Handling rest arguments that way is
very useful. It's not at all clear there's a use for doing this
anywhere case, other than to scratch that consistency itch.
mike
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From jetty to war?
Ok, I've got a simple web application that works running on embedded
jetty using the ring jetty adapter. I would now like to deploy it in
an infrastructure that will restart it if it dies, the system reboots,
etc. I've already got tomcat doing most of that, so the obvious choice
is a WAR file. Trouble is, trying the obvious thing from the
documentation doesn't work. The examples I find on the web all either
fail the same way, don't build (given that this is all new and still
rapidly evolving software, understandable), or involve using another
level of software. I chose ring because it looked like I could use
ring handlers in a number of different web servers without that extra
level.
Ok, this is the working serlvet.clj file: It picks up the handler from
x10.core, and then runs that:
(ns x10.servlet
[:use [x10.core :only (handler)]
ring.adapter.jetty
ring.middleware.reload ring.middleware.stacktrace])
(def app
(- #'handler
(wrap-reload '(x10.core))
(wrap-stacktrace)))
(defn boot [] (run-jetty #'app {:port 8088}))
The goal is to get the same handler running in a server framework.
I'm trying tomcat via a WAR file: based on the ring documentation, I
added war.clj (this is just the latest variant):
(ns x10.war
[:use [x10.core :only (handler)]
ring.util.servlet])
(defservice handler)
Then added ring/ring-servlet to the project.clj :dependencies, an
:aout pointing x10.war, and build it using leiningen-war. Deploying
the resulting war file gets tomcat log messages about not being able
to create a SESSIONS.ser file, and a web page complaining that The
requested resource (/x10/) is not available.
I did try building/deploying the compjure war example, and that at
least shows me the static page, so I believe the tomcat install is
correct.
Anyone got pointers to how to generate a WAR file for a simple
application, or suggestions on how to fix war.clj? Anything else you
might need to see to fix this?
Alternatively, instructions for deploying the same handler on either a
stand-alone (instead of an embedded) jetty, or on httpcore?
Thanks
mike
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Re: A question regarding map destructuring
On Mon, 1 Nov 2010 19:25:59 -0700 (PDT)
Mike K mbk.li...@gmail.com wrote:
This question is a bit abstruse, so please bear with me :-)
[elided]
So this can't be how it works, but I don't know how else to interpret
the documentation. Is this a special case meaning if there are
optional arguments AND they are to be destructured via a map, then
insert them pairwise into a map instead of a vector? Or does this
behavior fall directly out of the destructuring rules without a
special case based on something I'm missing?
My gut reaction is that you found a bug. This behavior was added in
1.2, as noted in the change log:
== 2.3 Destructuring Enhanced ==
If you associatively destructure a seq, it will be poured into a map first:
(defn foo [ {:keys [a b c]}]
[a b c])
(foo :c 3 :b 2)
= [nil 2 3]
I don't see anything about optional arguments there, just that using
a map to destructure a sequence should cause it to be converted to a
map. Which to me means your second (failing) example ought to work, so
that:
user= (let [{a :a} [:a 2 :b 3]] [a])
[nil]
should return [2], not [nil]. Unfortunately, the doc at
http://clojure.org/special_forms on bindings doesn't cover this
case. Given that the doc I did found was a change log, I wouldn't put
to much credence on it - those generally aren't definitive. But I'd
like to see a definitive answer as well.
mike
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Re: Can't locate str_utils in classpath
On Sun, 31 Oct 2010 00:09:31 -0700 (PDT) Steven Arnold thoth.amon.i...@gmail.com wrote: That was it. I had to add the entire path up to and including to contrib jar in order for clj to work. Merely adding the directory to the classpath was not sufficient, and the clj script ignored the value of my env variable $CLASSPATH, so I had to edit the clj script itself to get this working. Hi Steve, You ought to be able to add path/to/directory/\* to your CLASSPATH to pick up all the jars in the directory. The * needs to be quoted to show up in the variable, and not expanded by the shell. This works on Unix and Windows, so it ought to work on OSX. If you're interested in how to work with clojure with minimal Java infrastructure, I posted my writeup at http://www.mired.org/home/mwm/papers/simple-clojure.html mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: to macro or not?
On Thu, 28 Oct 2010 12:55:55 -0700 Raoul Duke rao...@gmail.com wrote: hi, not looking to stir up a pot, looking to learn from people's experience. i've heard that in CL land, one is told to avoid macros as long as possible. i've heard other folks in the Clojure world say that if you aren't using macros, then sorta why bother use a Lisp since you are missing out on one of the most powerful differentiators. then reading about Conj it sounds like some folks say stay away from macros if you can. Actually, these aren't really contradictory views. Macros are a powerful feature, and tend to be noted as the thing that sets LISPs apart from other languages. When you need them, nothing else will do the job. But they have downsides. For instance, they aren't a function, so aren't suitable to use as arguments to higher-order functions (another big part of LISP). So if you can do the job with a function, use a function instead. any way of teasing out when macros are ok? :-) i mean, are they only ok for the internals of the Clojure system? Last time it came up, there were three basic reasons given: 1) You need to control how many times an argument is evaluated. Commonly, either not at all or once, but possibly more than once. 2) Moving what you can of the computation into the compilation phase. This is a performance hack, so you should be converting functions to macros here. 3) You need it to get the API syntax you want (most commonly, a DSL). mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: to macro or not?
On Fri, 29 Oct 2010 06:30:27 +0530 Santosh Rajan santra...@gmail.com wrote: On Fri, Oct 29, 2010 at 1:58 AM, Mike Meyer mwm-keyword-googlegroups.620...@mired.org 3) You need it to get the API syntax you want (most commonly, a DSL). This last point is what I consider the most powerful feature of any language. And thats what makes Lispy languages a class apart. Use a macro where ever a particular type of problem, or solution to it, can be expressed more clearly using a macro, and the type of problem reappears more than once. I disagree - but I'm a big fan of code that writes code (this would be the second case - moving computations into the compiler). Computers are a multiplier, in that they multiply the number computations (for a loose definition of computation) that a single human can do by many orders of magnitude. Macros (or code that writes code) make writing code become the computation being multiplied. LISP macros are the most effective way I know of writing code that writes code. The alternatives involve multiple languages, or writing files that are then fed back to the language processor. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: to macro or not?
On Thu, 28 Oct 2010 18:12:39 -0700 (PDT) andrei andrei.zhabin...@gmail.com wrote: I'll try to extend Mike's answer by one more example. Consider `and` Lisp macro. It is not a function, because it must evaluate it's arguments lazily, and using macros is the only way to do it. Actually, this is the first case, and a classic example of it: you need to control how many times the arguments are evaluated. But try to apply `and` to the list of values (I know, that it's a job for a function `every?`, but how will you implement this function itself?): (apply and (list true true false true)) == error And this is the issue of not being able to pass macros to higher order functions. You cannot do it, since and is not a function. So, you need to use wrapper around `and`: (reduce #(and %1 %2) (list true true false true)) == false And this is still not the perfect solution, since it is not lazy. So you can see both advantages and disadvantages of using macros. Which is why you only want to use them when you have to. If you don't need the advantages, why put up with the disadvantages? mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Improving Contrib
On Wed, 20 Oct 2010 09:59:26 -0600 Eric Schulte schulte.e...@gmail.com wrote: Mike Meyer mwm-keyword-googlegroups.620...@mired.org writes: It was also more work than submitting patches looks to be for apache, django, gnu FWIW in gnu projects if your patch is 10 lines long then they do require you to go through a fairly lengthy attribution process. http://www.gnu.org/prep/maintain/html_node/Copyright-Papers.html Two things. First, the limit is around 15 lines of code, excluding repeated changes, and it applies over all patches, not just one: http://www.gnu.org/prep/maintain/html_node/Legally-Significant.html More importantly, this doesn't happen until *after* the patch has been submitted and a contributor decides it should be included. Putting roadblocks in front of people who want to submit patches or bugs - and not being able to update the bug database qualifies, since you can't report on the results of suggested fixes or at the very least add another case to the existing ticket without a developer having to notice the duplicate and flag it - is a bad idea. Again, maybe it's possible to submit bugs to assembla without the CA; but finding the assembla tickets list itself requires wading past the verbiage about the CA. If bug reports (with or without patches) doesn't require a CA, then it should be a lot easier to find. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: getting started with clojure
On Wed, 20 Oct 2010 18:04:17 -0400 Eric Lavigne lavigne.e...@gmail.com wrote: The short answer is that it's okay to use Clojure directly. You don't need Leiningen. If you are familiar with C programming, the difference between the Clojure compiler and Leiningen is like the difference between GCC and Make. Using the compiler directly is fine when you have only one file of source code and aren't using any libraries. Using the compiler directly is still possible with larger projects, but it can get tedious. Then it is useful to have a build tool that makes it easier to perform an operation on the project as a whole, rather than on individual files. I wrote up a guide to using clojure without having to deal with Leiningen and other elements that seem to come from the Java infrastructure. You can find it at http://www.mired.org/home/mwm/papers/simple-clojure.html mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Improving Contrib
On Tue, 19 Oct 2010 16:26:24 -0700 (PDT) Rich Hickey richhic...@gmail.com wrote: On Oct 19, 7:01 pm, Mike Meyer mwm-keyword-googlegroups. 620...@mired.org wrote: On Tue, 19 Oct 2010 15:51:17 -0700 (PDT) Mibu mibu.cloj...@gmail.com wrote: The greatest impediment for me is having to sign a contract to participate in an open source project. I understand Rich Hickey and most of you guys live in the litigious US and have to cover yourselves, but I feel not right about this. I've never run into a project - US-based or not - that required this. http://www.apache.org/licenses/ http://openjdk.java.net/contribute/ http://forge.mysql.com/wiki/Contributing_Code https://fedoraproject.org/wiki/Legal:Revised_Fedora_CLA_Draft#FPCA_Text http://contributing.openoffice.org/programming.html http://www.gnu.org/licenses/gpl-faq.html#AssignCopyright http://framework.zend.com/wiki/display/ZFPROP/Contributor+License+Agreement http://www.djangoproject.com/foundation/cla/faq/ http://nodejs.org/cla.html http://www.10gen.com/contributor The ones I've checked or am familiar with apparently define contribute differently than the clojure project does, in that they allow you to both subscribe to the developer list(s) and submit bug reports - including patches - without having to sign and post a contributor agreement. Or maybe it's the clojure web site making things difficult to find. Nuts, I happened to apply for my Chickasaw Nation citizenship today - which gives me tribal voting rights, free health care at tribal hospitals and clinics, the ability to get grants for education, housing, free laptops, etc, etc, etc. That was less work than being allowed to submit a bug to the issue tracking system for clojure (unless I just didn't find the right page). It was also more work than submitting patches looks to be for apache, django, gnu, fedora, or openoffice (from your list, though it sounds like openoffice may changed for the worse) or I know to be for FreeBSD, PostreSQL, OpenSolaris, Python, Cheetah, to name some I've been using for a while. Sure, many of them require you to create an account to submit any bug report. But that's straightforward, and a not unreasonable anti-spam measure. Some even require you to click a checkbox assigning the rights to anything you submit to the project in question as part of that process. But I can still contribute patches to these projects without having to print, sign and post any kind of developer agreement. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: Pros and cons of macro versus functions
On Mon, 18 Oct 2010 08:58:48 -0400 (EDT) lprefonta...@softaddicts.ca wrote: Choose functions over macros when you can write an equivalent function. From the LISP community, I'd put it slightly stronger: Only use macros when you have to. But you get the same set of reasons (with explanations). I use macros when: a) I have a repetitive pattern in the code that cannot be easily turned into a function (too much context to pass as args to a function). You can then hide a binding form in the macro to refer to the context or directly refer to it (global vars, ...) using form expansion. You can wrap huge chunks of your code in the macro referring to the context ( body) easily. If I understand you correctly, these would be non-hygienic macros. Yeah, those are pretty much have to. b) I need to evaluate the args (aka the symbols) to alter the form(s) generated by the macro and do not want immediate evaluation. And much of the time, this is because you're not sure you want to evaluate the form at all, or may want to evaluate it more than once. Again, a have to situation. c) I need a lighter syntax. You can marshall the symbols themselves as you wish to refer to other context bindings by sufixing/prefixing the synbol names. I wrote an interactive report utility used by non-lispers and that helped remove some Clojure syntax requirements that would look obscur to non-Lispers. The report utility can refer to global bindings while the user uses nicknames and other syntatic sugars to simplify the calls. This hides references to the context that would clutter the report code and make the tool unusable for the average user. In other words, building DSL's. This is a qualified have to: have to to meet user requirements. d) I see some potential in tuning the forms later (maybe to create functions) but do not want to embark on that journey now. Using macros you can defer retooling of your code or hide partial retooling until you are ready to change the top form to its definitive look. General performance reasons? Yeah. In particular, if you can replace run-time decisions with compile time-decisions (loop unrolling, etc.) you can win quite a bit here. Another qualifed have to: have to to meet performance requirements. mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: precise numbers
On Thu, 14 Oct 2010 00:27:39 +0200 Felix H. Dahlke f...@ubercode.de wrote: On 13/10/10 22:28, David Sletten wrote: On Oct 12, 2010, at 5:44 PM, Brian Hurt wrote: For example, in base 10, 1/3 * 3 = 0.9... It may seem counterintuitive, but that statement is perfectly true. 1 = 0.... That's a good test of how well you understand infinity. I'm clearly not a mathematician, but doesn't 0.9... asymptotically approach 1, i.e. never reaching it? How is that the same as 1? This representation implies the sum of the series (iterate #(/ % 10) 9/10), and that sum behaves as you say. However, since the series is infinite, you can prove that the number it represents is actually equal to one, like so: 1) a = 0.999... # define a as 0.999... 2) 10a = 9.999... # multiply both sides by 10 3) 10a - a = 9.999... - 0.999...# subtract equation 1 from equation 2 4) 9a = 9 # simplify 5) a = 1# divide both sides by 9. The subtraction step doesn't work unless the sequence is infinite, if a is any finite sequence of 9s, you'll get a number whose decimal representation is matches the re 8\.(9)*1. This relies on the property that adding 1 to an infinite number gives you back the same infinite number, so that: (= (rest (map #(* % 10) (iterate #(/ % 10) 9/10))) (iterate #(/ % 10) 9/10)) is true, but I don't recommend typing that into a repl to check it! Hmm. I wonder if you could represent irrationals as lazy sequences, and do arithmetic on those? mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: precise numbers
On Tue, 12 Oct 2010 12:35:24 -0700 (PDT) cej38 junkerme...@gmail.com wrote: The more that I think about it, the more I would rather have a set of equalities that always work. float= was a good try. Then you can't use floats. As others have explained, floats are imprecise by nature, being limited to finite binary fractions. To make matters worse, you don't input the numbers in binary, but in decimal, which means most of the fractions you can input can't be represented as a float - so you get an approximation. Given that the numbers are fuzzy, the concept of equality also becomes fuzzy - whether two numbers are equal will depend on the context. So you have to choose the equality that's appropriate for the context. If you want precise numbers, Clojure has three options: 1) If you can represent everything as integers, then BigInteger is probably the easiest to use, with the obvious drawback that it can't handle fractional values, nor can it represent as large a value as a float since you run out of memory. Letting units represent 1/1000's: user (- 123050 123049) 1 2) If you're going to stay in the world of decimal fractions, use BigDecimal. This has some of the problems of floats, but between allowing arbitrary precision and the input representation matching the internal representation, they're not nearly as obnoxious. user (- 12.305M 12.3049M) 0.0001M 3) Clojure's rationals let you represent all rational values, until you run out of memory. If you want a decimal approximation after the calculation is done, that's easy to get as well: user (- 12305/1000 123049/1) 1/1 user (float (- 12305/1000 123049/1)) 1.0E-4 mike -- Mike Meyer m...@mired.org http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information. O ascii ribbon campaign - stop html mail - www.asciiribbon.org -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
