[Haskell-cafe] ICFP Programming Contest 2007
Want to show off your programming skills? Your favorite programming language? Your best programming tools? Join the ICFP Programming Contest 2007! The 10th ICFP Programming Contest celebrates a decade of contests. This is one of the world's most advanced and prestiguous programming contest you can enter. For free! Book July 20 - 23, 2007. Check out http://www.icfpcontest.org/. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Is Excel a FP language?
On 25/04/07, Tony Morris [EMAIL PROTECTED] wrote: In a debate I proposed Excel is a functional language. It was refuted and I'd like to know what some of you clever Haskellers might think :) By coincidence I wrote about Excel (and related spreadsheets) as functional languages just recently [1]. It was prompted by an article in the BMJ where a spreadsheet cell was accidentally overwritten by patient data, meaning a small child was given their weight as a drug quantity, rather than the quantity being calculated from their weight. [1]: http://brokenhut.livejournal.com/233310.html Cheers, D. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Is Excel a FP language?
On 4/24/07, Tony Morris [EMAIL PROTECTED] wrote: In a debate I proposed Excel is a functional language. It was refuted and I'd like to know what some of you clever Haskellers might think :) My opposition proposed (after some weeding out) that there is a distinction between Excel, the application, the GUI and Excel, the language (which we eventually agreed (I think) manifested itself as a .xls file). Similarly, VB is both a language and a development environment and referring to VB is a potential ambiguity. I disagree with this analogy on the grounds that the very definition of Excel (proposed by Microsoft) makes no distinction. Further, it is impossible to draw a boundary around one and not the other. I also pointed to the paper by Simon Peyton-Jones titled, Improving the world's most popular functional language: user-defined functions in Excel, which quite clearly refers to Excel as a [popular] functional language. The debate started when I referred to the fact that financial institutions change their functional language from Excel to something like OCaml or Haskell. Of course, there is no doubting that these companies can replace their entire use of Excel with a functional language, which I think is almost enough to fully support my position (emphasis on almost). -- Tony Morris http://tmorris.net/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe Okay.. Excel consists of some c/c++ code, some visual basic, and some sort of cell evaluation engine. The c/c++ and vb are definitely not functional. Is the cell evaluation engine one? I think not. I do not believe what you can type into those cells does constitute a programming language, or at least not a turing complete one. As far as i know only simple calculations can be performed. For example, is there any way to evaluate f(2) = 0, f(x) = 5 without invoking vba (how does vba affect the dynamic?). As far as i understand you can compose functions by stringing cells together, higher level functions or values, but the contents of the cells themselves are heavily restricted. I am obviously no Excel guru but I believe that if you can prove it a programming language then you can probably prove that it is a functional one. --ryan ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: [Haskell] ANN: IOSpec 0.1
Hi Twan, Wouter Swierstra wrote: Test.IOSpecVersion 1.0 Shouldn't that be 0.1? You're right of course. You use Dynamic for the data type in IORefs, this has the unfortunate consequence of needing Typeable constraints. You could try to use unsafeCoerce instead, type Data = () unsafeToData :: a - Data unsafeToData = unsafeCoerce unsafeFromData :: Data - a unsafeFromData = unsafeCoerce I think this should be just as safe as Dynamic, since internally Dynamic uses unsafeCoerce as well. Just steal the details from there. I'm not entirely happy with the unsafeFromDynamic approach I use at the moment. GHC can derive instances of Typeable, so the price you have to pay is not too high. The real problem is that Haskell's type system is not expressive enough to cleanly describe the type of the heap (I know, I could be using HList, but still...). If you're interested, I also have a dependently typed version of the code for IORefs that allows heterogeneous, type-safe, well-scoped pointers. I should probably mention that an ulterior motive for this work is integrating IO in dependently typed languages such as Epigram. It is all, of course, still very much subject to active research. Wouter This message has been checked for viruses but the contents of an attachment may still contain software viruses, which could damage your computer system: you are advised to perform your own checks. Email communications with the University of Nottingham may be monitored as permitted by UK legislation. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: [Haskell] ANN: IOSpec 0.1
Hi Isaac, Moving to Haskell-cafe How does or might this relate to the typeclass-based Restricted IO monad http://article.gmane.org/gmane.comp.lang.haskell.general/14526 ? RIO's technique has the advantage that multiple capabilities can be easily combined in one use of the monad - but this manner of using typeclasses might interfere with how testable it is? (I think that should be okay... Also that this is a really neat project - incremental progress on taming Haskell IO in practice!) Stefan is absolutely right. The RIO, as far as I remember, restricts which parts of the IO monad you use. The same could be said for the Test.IOSpec modules. However, the Test.IOSpec also give you a pure specification of the functions you are using. This is very important if you want to trace/debug an execution of you code - you can see how the state of your machine changes at every step. There's also a bit finer control over how you test your functions: concurrent code is parameterised over the scheduler, for instance. Both these aren't possible with the RIO approach. P.S. why *If you're an ICFP referee, you may want to avoid reading any further* ICFP has a double-blind review process: if I were to submit a paper, I should do so anonymously. The idea behind it all is that if the reviewers don't know who the author of a paper is, they can't be prejudiced. The code I just released is described in a paper submitted to ICFP. All the best, Wouter This message has been checked for viruses but the contents of an attachment may still contain software viruses, which could damage your computer system: you are advised to perform your own checks. Email communications with the University of Nottingham may be monitored as permitted by UK legislation. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: [Haskell] ANN: IOSpec 0.1
Hi Stefan, in the Teletype module, it would probably be better to reflect IOTeletype operations as: data Action a = Finish a | Put Char (Action a) | Get (Char - Action a) That way, there is no need to use (unobservable) laziness. I'm afraid I've lost you. How does this differ from the current definition of IOTeletype? Thanks, Wouter This message has been checked for viruses but the contents of an attachment may still contain software viruses, which could damage your computer system: you are advised to perform your own checks. Email communications with the University of Nottingham may be monitored as permitted by UK legislation. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Is Excel a FP language?
My opposition proposed (after some weeding out) that there is a distinction between Excel, the application, the GUI and Excel, the language (which we eventually agreed (I think) manifested itself as a .xls file). Similarly, VB is both a language and a development environment and referring to VB is a potential ambiguity. I disagree with this analogy on the grounds that the very definition of Excel (proposed by Microsoft) makes no distinction. Further, it is impossible to draw a boundary around one and not the other. without commenting on excel, i believe this separation of development environment and language is outdated. development environments are no good unless they are intimately aware of the language and language designers should keep development environments in mind. language designs get too complicated if they try to cover issues that are better handled in the development environment, and such environments are much easier to create for languages supportive of such efforts. recent trends in semantics-aware ides highlight one side of the association, and of course, there are the ancient lisp and smalltalk, where the languages not only ease tool development, but trying to understand smalltalk as a notation only, rather than an image-based language/environment, is really missing half the point. claus ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Reasoning [was: Tutorial on Haskell]
Tim Newsham [EMAIL PROTECTED] wrote: - What about program proofs? Are there any systems that tie directly into haskell and let you augment your haskell program with a proof that can be machine checked? Programatica. http://www.csee.ogi.edu/PacSoft/projects/programatica/ You can write properties in the PLogic specification language (in comments within your program), and have them translated to the Alfa/Agda theorem prover. (However, I haven't seen much development activity on the Programatica project for a couple of years now.) Regards, Malcolm ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Is Excel a FP language?
Hi Tony, I think Lennart said it best with Excel is a zero-order functional language - a functional language in which you can't define functions. Another way of putting that is that it is a functional language, but a really bad one (from a functional'ness perspective). Thanks Neil On 4/25/07, Tony Morris [EMAIL PROTECTED] wrote: In a debate I proposed Excel is a functional language. It was refuted and I'd like to know what some of you clever Haskellers might think :) My opposition proposed (after some weeding out) that there is a distinction between Excel, the application, the GUI and Excel, the language (which we eventually agreed (I think) manifested itself as a .xls file). Similarly, VB is both a language and a development environment and referring to VB is a potential ambiguity. I disagree with this analogy on the grounds that the very definition of Excel (proposed by Microsoft) makes no distinction. Further, it is impossible to draw a boundary around one and not the other. I also pointed to the paper by Simon Peyton-Jones titled, Improving the world's most popular functional language: user-defined functions in Excel, which quite clearly refers to Excel as a [popular] functional language. The debate started when I referred to the fact that financial institutions change their functional language from Excel to something like OCaml or Haskell. Of course, there is no doubting that these companies can replace their entire use of Excel with a functional language, which I think is almost enough to fully support my position (emphasis on almost). -- Tony Morris http://tmorris.net/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: Compilling GHC on Vista
There isn't a solution for the getPermissions issue; the bug is here: http://hackage.haskell.org/trac/ghc/ticket/1280. Monique: can you post the relevant section of config.log from your failed configure run? Cheers, Simon Monique Monteiro wrote: For backward compatibility reasons, I'm using GHC 6.2.2. So, if there is already a solution for this issue in the GHC repository, please let me know how to add it manually. I don't have problems with ./configure on Windows XP. On 4/24/07, Tom Schrijvers [EMAIL PROTECTED] wrote: I still get the same message even with these instructions. I guess it may be due to some Vista security checking... Do you still get the same error message in your config.log now? Or a different one? There is also an error on Vista with checking whether a file is executable. I don't know whether there's already a solution for that in the repository? Tom Cheers, Monique On 4/24/07, Simon Marlow [EMAIL PROTECTED] wrote: Tom Schrijvers wrote: Here's the more complete error message: configure:3321: checking for C compiler default output file name configure:3348: c:/MinGW/bin/gccconftest.c 5 ld: /mingw/lib/crt2.o: No such file: No such file or directory configure:3351: $? = 1 configure:3389: result: configure: failed program was: configure:3396: error: C compiler cannot create executables See `config.log' for more details. Do make sure that MingW's bin/ and libexec/gcc/mingw32/3.4.2/ are the very first two in your path. I get the same error message if I don't do that. Hi Tom - would you mind adding the right incantation to the Vista instructions at the top of http://hackage.haskell.org/trac/ghc/wiki/Building/Windows? Cheers, Simon -- __ Monique Monteiro, MSc MCP .NET Framework 2.0 / SCJP / IBM OOAD Project Manager Recife Microsoft Innovation Center +55 81 34198137 http://www.cin.ufpe.br/~mlbm http://thespoke.net/blogs/moniquelouise/default.aspx [EMAIL PROTECTED] MSN: [EMAIL PROTECTED] ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe -- Tom Schrijvers Department of Computer Science K.U. Leuven Celestijnenlaan 200A B-3001 Heverlee Belgium tel: +32 16 327544 e-mail: [EMAIL PROTECTED] ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: Compilling GHC on Vista
Here is the complete message in config.log:
gcc version 3.4.2 (mingw-special)
configure:3288: $? = 0
configure:3295: c:/MinGW/bin/gcc -V 5
gcc.exe: `-V' option must have argument
configure:3298: $? = 1
configure:3321: checking for C compiler default output file name
configure:3348: c:/MinGW/bin/gccconftest.c 5
ld: /mingw/lib/crt2.o: No such file: No such file or directory
configure:3351: $? = 1
configure:3389: result:
configure: failed program was:
| /* confdefs.h. */
| #define PACKAGE_NAME
| #define PACKAGE_TARNAME
| #define PACKAGE_VERSION
| #define PACKAGE_STRING
| #define PACKAGE_BUGREPORT
| /* end confdefs.h. */
|
| int
| main ()
| {
|
| ;
| return 0;
| }
configure:3396: error: C compiler cannot create executables
See `config.log' for more details.
Cheers,
Monique
On 4/25/07, Simon Marlow [EMAIL PROTECTED] wrote:
There isn't a solution for the getPermissions issue; the bug is here:
http://hackage.haskell.org/trac/ghc/ticket/1280.
Monique: can you post the relevant section of config.log from your failed
configure run?
Cheers,
Simon
Monique Monteiro wrote:
For backward compatibility reasons, I'm using GHC 6.2.2. So, if there
is already a solution for this issue in the GHC repository, please let
me know how to add it manually.
I don't have problems with ./configure on Windows XP.
On 4/24/07, Tom Schrijvers [EMAIL PROTECTED] wrote:
I still get the same message even with these instructions. I guess it
may be due to some Vista security checking...
Do you still get the same error message in your config.log now? Or a
different one? There is also an error on Vista with checking whether a
file is executable. I don't know whether there's already a solution
for that in the repository?
Tom
Cheers,
Monique
On 4/24/07, Simon Marlow [EMAIL PROTECTED] wrote:
Tom Schrijvers wrote:
Here's the more complete error message:
configure:3321: checking for C compiler default output file name
configure:3348: c:/MinGW/bin/gccconftest.c 5
ld: /mingw/lib/crt2.o: No such file: No such file or directory
configure:3351: $? = 1
configure:3389: result:
configure: failed program was:
configure:3396: error: C compiler cannot create executables
See `config.log' for more details.
Do make sure that MingW's bin/ and libexec/gcc/mingw32/3.4.2/ are
the
very first two in your path. I get the same error message if I
don't do
that.
Hi Tom - would you mind adding the right incantation to the Vista
instructions
at the top of
http://hackage.haskell.org/trac/ghc/wiki/Building/Windows?
Cheers,
Simon
--
__
Monique Monteiro, MSc
MCP .NET Framework 2.0 / SCJP / IBM OOAD
Project Manager
Recife Microsoft Innovation Center
+55 81 34198137
http://www.cin.ufpe.br/~mlbm
http://thespoke.net/blogs/moniquelouise/default.aspx
[EMAIL PROTECTED]
MSN: [EMAIL PROTECTED]
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
--
Tom Schrijvers
Department of Computer Science
K.U. Leuven
Celestijnenlaan 200A
B-3001 Heverlee
Belgium
tel: +32 16 327544
e-mail: [EMAIL PROTECTED]
--
__
Monique Monteiro, MSc
MCP .NET Framework 2.0 / SCJP / IBM OOAD
Project Manager
Recife Microsoft Innovation Center
+55 81 34198137
http://www.cin.ufpe.br/~mlbm
http://thespoke.net/blogs/moniquelouise/default.aspx
[EMAIL PROTECTED]
MSN: [EMAIL PROTECTED]
___
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Re: [Haskell-cafe] Is Excel a FP language?
Is the cell evaluation engine one? I think not. I do not believe what you can type into those cells does constitute a programming language, or at least not a turing complete one. As far as i know only simple calculations can be performed. For example, is there any way to evaluate f(2) = 0, f(x) = 5 Sure. Should not be hard using 5 - 5 * (1-abs(sign(2-x))) I admit that I didn't test it using Excel but oocalc. Or is this VBA? You are right. I get your intention ;) Marc ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: HXT namespace problem
Tim Walkenhorst schrieb: runX $ constA (request TableListRequest) root [] [writeA] writeDocument [(a_indent,v_1)] - writeDocument [(a_indent,v_1), (a_check_namespaces, v_1)] - should do the trick. a_check_namespaces unfortunately didn't do the trick. But using uniqueNamespacesFromDeclAndQNames *before* constructing the root helped. But this was not very well documented. However, thanks for your help. Regards, Martin. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: release plans
Hello Simon, Tuesday, April 17, 2007, 11:51:07 AM, you wrote: The parallel GC code is currently sitting dormant waiting for me to go back to it and figure out why it isn't performing very well. Basically I saw little or no speedup regardless of how many CPUs I threw at it, which suggests that the bottleneck might be the memory system. I tried a few things - prefetching, for example - without much success. Simon, you can investigate influence of memory speed to GC speed by manipulating memory timings on standard GC. for example, you write random-memory-access program, measure its slowdown when you change memory timings, then measure slowdown of GC with the same memory timing change another variant - try to increase CPU speed without changing memory speed. if this don't allow to make GC faster (including parallel GC) - this means that process is memory-bound -- Best regards, Bulatmailto:[EMAIL PROTECTED] ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Program optimisation
Hello Andrew, Friday, April 20, 2007, 10:01:32 PM, you wrote: I have *no idea* if this is an appropriate place to put this, but here goes... http://haskell.org/haskellwiki/Library/AltBinary http://haskell.org/haskellwiki/Modern_array_libraries last article contains information about slowness of GC with boxed arrays. also, unboxed arrays of Complex are made via ForeignArray (starting from 6.6 it has the same speed as UArray) -- Best regards, Bulatmailto:[EMAIL PROTECTED] ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Programming Languages and Mechanised Mathematics -- deadline extension
[Extended deadline: submissions now due May 2nd, 2007] Programming Languages for Mechanized Mathematics Workshop As part of Calculemus 2007 http://www.risc.uni-linz.ac.at/about/conferences/Calculemus2007/ Hagenbergs, Austria June 29-30, 2007. The intent of this workshop is to examine more closely the intersection between programming languages and mechanized mathematics systems (MMS). By MMS, we understand computer algebra systems (CAS), [automated] theorem provers (TP/ATP), all heading towards the development of fully unified systems (the MMS), sometimes also called universal mathematical assistant systems (MAS) (see Calculemus 2007 http://www.risc.uni-linz.ac.at/about/conferences/Calculemus2007/). There are various ways in which these two subjects of /programming languages/ and /systems for mathematics/ meet: * Many systems for mathematics contain a dedicated programming language. For instance, most computer algebra systems contain a dedicated language (and are frequently built in that same language); some proof assistants (like the Ltac language for Coq) also have an embedded programming language. Note that in many instances this language captures only algorithmic content, and /declarative/ or /representational/ issues are avoided. * The /mathematical languages/ of many systems for mathematics are very close to a functional programming language. For instance the language of ACL2 is just Lisp, and the language of Coq is very close to Haskell. But even the mathematical language of the HOL system can be used as a functional programming language that is very close to ML and Haskell. On the other hand, these languages also contain very rich specification capabilities, which are rarely available in most computation-oriented programming languages. And even then, many specification languages (B, Z, Maude, OBJ3, CASL, etc) can still teach MMSes a trick or two regarding representational power. * Conversely, functional programming languages have been getting more mathematical all the time. For instance, they seem to have discovered the value of dependent types rather recently. But they are still not quite ready to 'host' mathematics (the non-success of docon http://www.haskell.org/docon/ being typical). There are some promising languages on the horizon (Epigram http://www.e-pig.org/, Omega http://web.cecs.pdx.edu/%7Esheard/Omega/index.html) as well as some hybrid systems (Agda http://agda.sourceforge.net/, Focal http://focal.inria.fr/site/index.php), although it is unclear if they are truly capable of expressing the full range of ideas present in mathematics. * Systems for mathematics are used to prove programs correct. (One method is to generate correctness conditions from a program that has been annotated in the style of Hoare logic and then prove those conditions in a proof assistant.) An interesting question is what improvements are needed for this both on the side of the mathematical systems and on the side of the programming languages. We are interested in all these issues. We hope that a certain synergy will develop between those issues by having them explored in parallel. These issues have a very colourful history. Many programming language innovations first appeared in either CASes or Proof Assistants, before migrating towards more mainstream languages. One can cite (in no particular order) type inference, dependent types, generics, term-rewriting, first-class types, first-class expressions, first-class modules, code extraction, and so on. However, a number of these innovations were never aggressively pursued by system builders, letting them instead be developped (slowly) by programming language researchers. Some, like type inference and generics have flourished. Others, like first-class types and first-class expressions, are not seemingly being researched by anyone. We want to critically examine what has worked, and what has not. Why are all the current ``popular''[1] computer algebra systems untyped? Why are the (strongly typed) proof assistants so much harder to use than a typical CAS? But also look at question like what forms of polymorphism exists in mathematics? What forms of dependent types exist in mathematics? How can MMS regain the upper hand on issues of 'genericity'? What are the biggest barriers to using a more mainstream language as a host language for a CAS or an ATP? This workshop will accept two kinds of submissions: full research papers as well as position papers. Research papers should be nore more than 15 pages in length, and positions papers no more than 3 pages. Submission will be through _EasyChair_. An informal version of the proceedings will be available at the workshop, with a more formal version to appear later. We are looking into having the best papers completed into full papers and published as a special issue of
Re[2]: [Haskell-cafe] COM and Haskell
Hello Andrew, Tuesday, April 24, 2007, 5:03:53 AM, you wrote: A core difficulty is the mismatch between the object-oriented type system of .NET and Haskell's. This is something that RubyCLR didn't need to conquer, Ruby already having object-oriented concepts. Simon Marlow recently wrote paper about handling dynamic exceptions - for me it seems that he described general system to mimic OOP in Haskell -- Best regards, Bulatmailto:[EMAIL PROTECTED] ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re[2]: [Haskell-cafe] faster factorial function via FFI?
Hello Dan, Tuesday, April 24, 2007, 3:25:39 AM, you wrote: Usings Ints everywhere isn't an option, because my final answers are definitely Integers -- although I might try using Ints in some places. I may be memoizing is the right answer? factorials :: Array Int Integer factorials = array (0,100) (map factorial [1..n]) -- Best regards, Bulatmailto:[EMAIL PROTECTED] ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: Compilling GHC on Vista
gcc version 3.4.2 (mingw-special) configure:3288: $? = 0 configure:3295: c:/MinGW/bin/gcc -V 5 gcc.exe: `-V' option must have argument configure:3298: $? = 1 configure:3321: checking for C compiler default output file name configure:3348: c:/MinGW/bin/gccconftest.c 5 ld: /mingw/lib/crt2.o: No such file: No such file or directory not sure whether this is relevant, but there is no drive letter in that library path. cygwin doesn't know about /mingw anyway, but if i am in a cmd shell, it does matter what drive i'm on, as absolute paths without drive letter will default to the root of that drive: D:\c:\mingw\bin\ld \mingw\lib\crt2.o -M | find OUTPUT c:\mingw\bin\ld: \mingw\lib\crt2.o: No such file: No such file or directory C:\c:\mingw\bin\ld \mingw\lib\crt2.o -M | find OUTPUT .. OUTPUT(a.exe pei-i386) claus ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Talking to the serial (RS232) port from Haskell
What's the easiest way, from Haskell, to open a serial port (under Windows, say) with the correct baud rate and parity, and send data through it? Is there a serial library for Haskell? -- Dan ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Talking to the serial (RS232) port from Haskell
On Wed, Apr 25, 2007 at 09:28:37AM -0700, Dan Piponi wrote: What's the easiest way, from Haskell, to open a serial port (under Windows, say) with the correct baud rate and parity, and send data through it? Is there a serial library for Haskell? Don't know wethere there are some libraries This is just the way I would go.. I did this long ago on Windows but there may be better ways now. Get DevCPP (because it ships with a WinAPI help file) search for COM or special device or openfile .. There you might get a reference to the functions you need to set baudrate etc In general all you need is opening a file with name COM1 on windows. I think you don't have to do all the ffi stuff yourself. There are windows api bindings already. I'd also recommend http://com0com.sourceforge.net/ . Perhaps try readFile COM1 and see wether it works. I'd also recommend http://com0com.sourceforge.net/ . Then you can use Windows HyperTerminal to see wether your application produces some output/ send data to your application to test it. I hope I didn't tell you too much rubbish from my memory ;) You can also wait till you get a better response. I hope I didn't tell you too much rubbish from my memory ;) Good luck Marc ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Is Excel a FP language?
I usually refer to Excel as a zeroth order functional language, i.e., you can't define any functions. :) (You can define functions if you do it in VBA or in an addin, but that's not really Excel, imo.) -- Lennart On Apr 25, 2007, at 04:00 , Tony Morris wrote: In a debate I proposed Excel is a functional language. It was refuted and I'd like to know what some of you clever Haskellers might think :) My opposition proposed (after some weeding out) that there is a distinction between Excel, the application, the GUI and Excel, the language (which we eventually agreed (I think) manifested itself as a .xls file). Similarly, VB is both a language and a development environment and referring to VB is a potential ambiguity. I disagree with this analogy on the grounds that the very definition of Excel (proposed by Microsoft) makes no distinction. Further, it is impossible to draw a boundary around one and not the other. I also pointed to the paper by Simon Peyton-Jones titled, Improving the world's most popular functional language: user-defined functions in Excel, which quite clearly refers to Excel as a [popular] functional language. The debate started when I referred to the fact that financial institutions change their functional language from Excel to something like OCaml or Haskell. Of course, there is no doubting that these companies can replace their entire use of Excel with a functional language, which I think is almost enough to fully support my position (emphasis on almost). -- Tony Morris http://tmorris.net/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Is Excel a FP language?
How about 'IF(x=2,0,5)' ? On Apr 25, 2007, at 13:48 , Marc Weber wrote: Is the cell evaluation engine one? I think not. I do not believe what you can type into those cells does constitute a programming language, or at least not a turing complete one. As far as i know only simple calculations can be performed. For example, is there any way to evaluate f(2) = 0, f(x) = 5 Sure. Should not be hard using 5 - 5 * (1-abs(sign(2-x))) I admit that I didn't test it using Excel but oocalc. Or is this VBA? You are right. I get your intention ;) Marc ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] RE: On reflection
Not only that, but when we have associated type synonyms going it'll be even
clearer. Instead of
class CoreProcessSyntax p a x | p - a x where
zero :: p
sequence :: a - x - p
compose :: [p] - p
you'll be able to write
class CoreProcessSyntax p where
type AThing p :: *
type XThing p :: *
zero :: p
sequence :: AThing p - XThing p - p
compose :: [p] - p
I'm not sure what the 'a' and 'x' parameters stand for, but they are
functionally dependent on 'p'; I've called these type functions AThing and
XThing, but you'll have more meaningful names. Now the type of 'sequence' is
much rmore perspicuous.
Simon
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Greg Meredith
Sent: 25 April 2007 04:27
To: [EMAIL PROTECTED]; Simon Peyton-Jones
Cc: haskell-cafe; Matthias Radestock; Matthew Sackman; Tristan Allwood
Subject: On reflection
Oleg, Simon,
Thanks for your help. If i understand it correctly, the code below gives a
reasonably clean first cut at a demonstration of process calculi as
polymorphically parametric in the type of name, allowing for an instantiation
of the type in which the quoted processes play the role of name. This is much,
much cleaner and easier to read than the OCaml version.
Best wishes,
--greg
{-# OPTIONS -fglasgow-exts -fallow-undecidable-instances #-}
module Core(
Nominal
,Name
,Locality
,Location
,CoreProcessSyntax
,CoreAgentSyntax
,MinimalProcessSyntax
,MinimalAgentSyntax
,ReflectiveProcessSyntax
-- ,make_process
)
where
-- What's in a name?
class Nominal n where
nominate :: i - n i
-- newtype Name i = Nominate i deriving (Eq, Show)
newtype Name i = Name i deriving (Eq, Show)
instance Nominal Name where nominate i = Name i
-- Where are we?
class Locality a where
locate :: (Eq s, Nominal n) = s - (n i) - a s (n i)
name :: (Eq s, Nominal n) = a s (n i) - (n i)
-- data Location s n = Locate s n deriving (Eq, Show)
data Location s n = Location s n deriving (Eq, Show)
instance Locality Location where
locate s n = Location s n
name (Location s n) = n
-- Constraints
class CoreProcessSyntax p a x | p - a x where
zero :: p
sequence :: a - x - p
compose :: [p] - p
class CoreAgentSyntax x p n | x - p n where
bind :: [n] - p - x
offer :: [n] - p - x
-- Freedom (as in freely generated)
data MinimalProcessSyntax l x =
Null
| Sequence l x
| Composition [MinimalProcessSyntax l x]
data MinimalAgentSyntax n p =
Thunk (() - p)
| Abstraction ([n] - p)
| Concretion [n] p
-- Responsibility : constraining freedom to enjoy order
instance CoreProcessSyntax (MinimalProcessSyntax l x) l x where
zero = Null
sequence l a = Sequence l a
compose [] = zero
compose ps = Composition ps
instance CoreAgentSyntax (MinimalAgentSyntax n p) p n where
bind [] proc = Thunk (\() - proc)
-- -- TODO : lgm : need to substitute m for name in proc
bind (name:names) proc = Abstraction (\m - comp $ bind names proc)
where comp (Thunk fp) = fp ()
-- comp (Abstraction abs) = abs name
offer names proc = Concretion names proc
data ReflectiveProcessSyntax =
Reflect
(MinimalProcessSyntax
(Location [(Name ReflectiveProcessSyntax)] (Name ReflectiveProcessSyntax))
(MinimalAgentSyntax (Name ReflectiveProcessSyntax)
ReflectiveProcessSyntax))
-- instance (CoreProcessSyntax p a x) =
-- CoreProcessSyntax
-- (MinimalProcessSyntax
-- (Location
-- [(Name (MinimalProcessSyntax a x))]
-- (Name (MinimalProcessSyntax a x)))
-- (MinimalAgentSyntax
-- (Name (MinimalProcessSyntax a x))
-- (MinimalProcessSyntax a x)))
-- (Location
-- [(Name (MinimalProcessSyntax a x))]
-- (Name (MinimalProcessSyntax a x)))
-- (MinimalAgentSyntax
-- (Name (MinimalProcessSyntax a x))
-- (MinimalProcessSyntax a x))
--
L.G. Meredith
Managing Partner
Biosimilarity LLC
505 N 72nd St
Seattle, WA 98103
+1 206.650.3740
http://biosimilarity.blogspot.com
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Re: [Haskell-cafe] Is Excel a FP language?
Albert Y. C. Lai wrote: I say Excel is a functional language. If there needs to be the quoted distinction, fine: Excel the language is a functional language, and Excel the application is an interpreter of said language. Excel has functions, but does it treat functions as it treats other data? I don't think so, and that makes it non-functional (dys-functional?). As for VB... that may be functional, in the same sense as XSLT is: if you step back and squint, it almost looks vaguely like a functional language. (Does the opposition self-consistently distinguish Perl the language from perl.exe the interpreter?) Only perl can parse Perl. (Yes, they do.) -Udo -- Science is like sex - sometimes something useful comes out of it, but that's not what we are doing it for. -- Richard Feynman signature.asc Description: Digital signature ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] How Albus Dumbledore would sell Haskell
Since no one mentioned automatic differentiation (AD), I will. I think AD is a nice example of using type classes and higher order functions to get small and useful code. Maybe this example is not ideal for the audience, but anyway, Simon has the last word. Here is how demo would go: Define a polynomial with roots at -9, 0 and 9: Main let poly x = (x + 9) * x * (x - 9) check type: Main :t poly poly :: (Num a) = a - a then explain type and handwave a bit about the polymorphism +overloading and the type. Check that it works: Main poly 2 -154 Main poly 9 0 Aha, it works. Let's see a graph then (sorry if the email formatting destroys the graph): Main draw poly ** | * ***| ** * | * ** | * *| --*-***- * | ** * | * ** * |*** * | ** Oh did I mention that 'draw' is a higher order function? (handwavy explanation of H.O. functions, bla bla) Main :t draw draw :: (Double - Double) - IO () Now define, first derivative of poly: Main let poly' x = d poly x (Note that x is required because of monomorphism restriction, but I wouldn't mention it). and test it: Main draw poly' * | * | * **|** * | * * | * **|** ** | ** --**-**- | * one can do it once again: Main let poly'' x = d poly' x Main draw poly'' |*** | | | * | *| | | *** | The nice thing is that the code for d is very small (unlike the drawing code, for example): data Dual a = Dual a a deriving (Eq,Show) instance (Num a) = Num (Dual a) where (Dual x y) + (Dual x' y') = Dual (x+x') (y+y') (Dual x y) * (Dual x' y') = Dual (x*x') (x*y'+y*x') negate (Dual x y) = Dual (negate x) (negate y) fromInteger n = Dual (fromInteger n) 0 (omitting some methods here) Below, d is a H.O. function bla bla type Poli = forall a.(Num a) = a - a d :: Poli - Poli d f x = case f (Dual x 1) of Dual f_x f'_x - f'_x end of pseudo-demo This code is based on a blog post[1] which is in turn based on some nice posts by Dan Piponi. It's nothing new, but it's worthwhile to stress how easy it is to do this kind of thing in Haskell. Cheers, Alexey [1] http://insomne.pinguinos.org/2006/06/25/derivacion-automatica- utilizando-numeros-duales-y-clases-type-classes/ On Apr 19, 2007, at 10:05, Simon Peyton-Jones wrote: | Simon (aka Dumbledore) is speaking to four different Houses: scientists | (Ravenclaw), engineers (Hufflepuff), entrepreneurs (Slytherin), and | managers (Griffindor). I wish I could live up to this image! Lots of interesting ideas on this thread, and Haskell-Cafe threads are *supposed* to wander a bit. But, just to remind you all: I'm particularly interested in concrete examples (pref running code) of programs that are * small * useful * demonstrate Haskell's power * preferably something that might be a bit tricky in another language I have lots of *general* ideas. What I'm hoping is that I can steal working code for one or two compelling examples, so that I can spend my time thinking about how to present it, rather than on dreaming up the example and writing the code. (But don't let me inhibit wider-ranging discussion as well.) thanks Simon ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] How Albus Dumbledore would sell Haskell
I don't know how many of the other people on this list are actually going to *be* at OSCON. I will. I think it is important to think about the kinds of problems the audience is trying to solve, as well as the context in which they are trying to solve them. For the most part, the attendees at OSCON work on system software: operating systems, operating system services (printing, packaging, scheduling, etc), network distributed computing infrastructure, databases, languages, and every imaginable variation on the word web. 1) Build a simple database access layer that is immune to SQL injection attacks from user input (using the type system to guarantee that safety). Include the FFI portion (FFI is a point of paranoia about any new language). Now the, the audience values the type system. 2) Show something appallingly simple, yet blazingly fast. Demonstrate that it is blazingly fast. I would implement wc -l using data.Bytestring.lazy and run in over a huge file. It's a one line program and it will run faster than the built in unix command. Explain that its fast because of GHCs rewrite rules. Explain that the rewrite rules are only possible because of purity. Now the, the audience values purity. 3) Build a simple combinator framework that supports multiple evaluation schemes (like your derivative framework that supported both valuation and settlement processes). For this audience, it might be cool to build a simple package system that both installed software and later verified the integrity of the installation. Although, if you *wanted* to present How to write a financial contract I could not object. Quantitative finance is my business and I promise to be in the audience for this. Also, see if Audrey Tang is going to be present. If she is, consider enlisting her support. Haskell has *enormous* credibility in the Perl 6 community because of PUGS. I recently had a conversation with Jesse Vincent, the Perl 6 program manager. He said that the majority of the Perl 6 community is aware that PUGS (and therefore Haskell) are crucial to the success of Perl 6. Perl has its own track at this conference. reilly hayes ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
