Re: Confusing interplay between macros and metadata
Tassilo Horn tass...@member.fsf.org writes: I'm facing the same issue. I have this macro for java interop: (defmacro with-traversal-context [[g tc] body] `(let [old-tc# (.getTraversalContext ^Graph ~g)] (try (.setTraversalContext ^Graph ~g ^TraversalContext ~tc) ~@body (finally (.setTraversalContext ^Graph ~g ^TraversalContext old-tc#) But the type hints are gone in the macro expansion, thus I have 3 reflection warnings per macro application, and real, performance critical reflection warnings get lost in the shuffle. What you appear to be having is actually the different, but conceptually-related problem of the metadata reader macro and unquote operations interacting in a way which is consistent, but potentially not optimal. Fortunately in your sort of situation, you can work around the problem by replacing the metadata reader macro with explicit metadata operations. Something like the following should work: (defn assoc-meta [x kvs] (with-meta x (apply assoc (meta x) kvs))) (defmacro with-traversal-context [[g tc] body] (let [g (assoc-meta g :tag Graph) tc (assoc-meta tc :tag TraversalContext)] `(let [^TraversalContext old-tc# (.getTraversalContext ~g)] (try (.setTraversalContext ~g ~tc) ~@body (finally (.setTraversalContext ~g old-tc#)) -Marshall -- 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
(newbie) - first question - split list of maps into map of maps based on distinct values
Hi all,
So finally I have managed to get to write some clojure. Gotta say, after
two days I am seriously excited - talk about removing ceremony and focusing
on the issue. I feel like a blind man performing surgery with welding
gloves on whilst holding this tiny but unbelievably powerful and mysterious
tool (compared to a seeing man performing surgery with welding gloves
expertly using the Java welding torch :)). I have *so* much learning to do
around clojure (and choosing appropriate metaphors :)) - I love it!
Anyway, my first (of many) questions:
I have a vector of maps generated as a result of an outer-join. I want to
convert that into a map of maps where the keys in the first map are the
distinct set of some key in vector of maps and the value is a vector of
maps that have that value.
For example, given:
[{:id 1, :name abc} {id:2 :name def} {id:1 :name xef}]
then coolFunctionWhichIsAlludingMe would return
{1 [{:id1 :name abc} {:id1 :name xef}] 2 [{id:2 :name def}]}
The context for this is if I do a select * from order join
order-line-items then I get a map from order to order-line-items.
I know this is 101 and I would be astonished if there wasn't a function
already in core to do this. I have read a gazillion resources around
Clojure as well (a while ago) but it is all surface knowledge and doesn't
stick until I actually get down to using the tools, which is happening now.
(I am sort-of apologising for taking up traffic with such a ridiculously
simple question :)).
Thanks!
Col
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Re: (newbie) - first question - split list of maps into map of maps based on distinct values
Sometimes the answer is just too simple: group-by (see the last post on http://stackoverflow.com/questions/3052162/coverting-a-vector-of-maps-to-map-of-maps-in-clojure) -- 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: Confusing interplay between macros and metadata
Marshall T. Vandegrift llas...@gmail.com writes: Hi Marshall, I'm facing the same issue. I have this macro for java interop: (defmacro with-traversal-context [[g tc] body] `(let [old-tc# (.getTraversalContext ^Graph ~g)] (try (.setTraversalContext ^Graph ~g ^TraversalContext ~tc) ~@body (finally (.setTraversalContext ^Graph ~g ^TraversalContext old-tc#) But the type hints are gone in the macro expansion, thus I have 3 reflection warnings per macro application, and real, performance critical reflection warnings get lost in the shuffle. What you appear to be having is actually the different, but conceptually-related problem of the metadata reader macro and unquote operations interacting in a way which is consistent, but potentially not optimal. Fortunately in your sort of situation, you can work around the problem by replacing the metadata reader macro with explicit metadata operations. Yes, that would probably do the trick. But on IRC, Alan already gave me this recipe (gensyming the given parameter g) which is even a bit shorter. --8---cut here---start-8--- (defmacro with-traversal-context [[g tc] body] `(let [^Graph g# ~g ^TraversalContext old-tc# (.getTraversalContext g#)] (try (.setTraversalContext g# ~tc) ~@body (finally (.setTraversalContext g# old-tc#) --8---cut here---end---8--- -- (What the world needs (I think) is not (a Lisp (with fewer parentheses)) but (an English (with more.))) Brian Hayes, http://tinyurl.com/3y9l2kf -- 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
Multiple try via macro
Hi! I would like to write macro, which tries to evalute one of statements. If exception happens the next statement is taken, if not then rest of expressions execution is stopped. (defmacro try-this[ body ] `(if (seq ~body) (try ~(first body) (catch Exception e# (try-this ~(rest body (throw (Exception. nothing succeed (try-this (/ 2 0) (+ 2 3) (println 2)) So the macro should expand to something like this: (try (/ 2 0) (catch Exception e (try (+ 2 3) (catch Exception e (try (println 2) (catch Exception e (Exception. nothing succeed))) Any help? -- 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
ANN: Fughetta 0.0.1
Releasing first versioned Fughettahttps://github.com/Sebastiansen/fughetta project with new functions and arrangements. Enjoy! -- 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: `conj` into maps
It may relate to the implementation of IPersistentCollection.cons(Object). As far as I know, the IPersistentCollection.cons(Object) method powers the polymorphic behavior of the `conj` function, and is the foundation for the persistent collections in general. -S -- 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: Multiple try via macro
Hi! I would like to write macro, which tries to evalute one of statements. If exception happens the next statement is taken, if not then rest of expressions execution is stopped. (defmacro try-this[ body ] `(if (seq ~body) (try ~(first body) (catch Exception e# (try-this ~(rest body (throw (Exception. nothing succeed (try-this (/ 2 0) (+ 2 3) (println 2)) So the macro should expand to something like this: (try (/ 2 0) (catch Exception e (try (+ 2 3) (catch Exception e (try (println 2) (catch Exception e (Exception. nothing succeed))) Any help? Something like: (defmacro try-this [ forms] (loop [[f more] forms] (when f `(try ~f (catch Throwable t# (try-this ~@more)) Stu Stuart Halloway Clojure/core http://clojure.com -- 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: form-zip
I see your point. Still it seems odd that the default zipper
generating function isn't one that understands the big 4 clojure
datastructures.
On Nov 8, 8:04 pm, Alan Malloy a...@malloys.org wrote:
They have a different make-node function, so that when you edit a
vector-zip you get vectors instead of something else. It's also easy
to imagine your data units are simple vectors, grouped together in
some kind of list structure. Then you would want the zipper to tell
you hey, this node is a leaf for vectors - thus seq-zip.
On Nov 8, 7:21 pm, George Jahad cloj...@blackbirdsystems.net wrote:
Now that I think of it, why are seq-zip and vector-zip separate
functions? Why not a single function that handles both seq and
vectors, and sets and maps too?
What am I missing?
On Nov 1, 8:56 pm, George Jahad cloj...@blackbirdsystems.net wrote:
surely this one's been written before, but i needed it the other day
and couldn't find it.
form-zip returns a zipper from a clojure form.
user= (require '[clojure.zip :as zip])
user= (use 'form-zip.core)
user= (- '{1 2 3 4} form-zip zip/next zip/remove zip/root)
{3 4}
fz-node-seq returns a seq of the nodes.
user= (fz-node-seq '{1 2 3 4})
({1 2, 3 4} [1 2] 1 2 [3 4] 3 4)
a one hour hack, probably full of edge cases i haven't thought of.
on clojars and github:https://github.com/GeorgeJahad/form-zip
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Re: Multiple try via macro
Thank you. Is loop and not for example let, for recursion optimalization? On Nov 9, 2:51 pm, Stuart Halloway stuart.hallo...@gmail.com wrote: Hi! I would like to write macro, which tries to evalute one of statements. If exception happens the next statement is taken, if not then rest of expressions execution is stopped. (defmacro try-this[ body ] `(if (seq ~body) (try ~(first body) (catch Exception e# (try-this ~(rest body (throw (Exception. nothing succeed (try-this (/ 2 0) (+ 2 3) (println 2)) So the macro should expand to something like this: (try (/ 2 0) (catch Exception e (try (+ 2 3) (catch Exception e (try (println 2) (catch Exception e (Exception. nothing succeed))) Any help? Something like: (defmacro try-this [ forms] (loop [[f more] forms] (when f `(try ~f (catch Throwable t# (try-this ~@more)) Stu Stuart Halloway Clojure/corehttp://clojure.com -- 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: Dynamic test creation?
Questions about tabular tests... * can they take a lazy-seq as input? * will the tests be parallelized? (i have anywhere from 10k-20k tests to run) On Nov 8, 4:16 pm, Alex Baranosky alexander.barano...@gmail.com wrote: Sounds lile you could use Midje's tabular tests. Or if you want write a acro to generate a tabular fact. Tje tabular fact will give you good reporting. On Nov 8, 2011 1:44 PM, AndyK andy.kri...@gmail.com wrote: I finally had a chance to try this out and it fails with error: java.lang.ClassCastException: java.lang.String cannot be cast to clojure.lang.IObj Compilation failed. When I substituted in something like this... (defn prn-form [n scenario] `(prn ~(str foo n) (prn ~(str n :: scenario the file did compile. Is the fact that deftest is also a macro going to cause a problem with the original idea? On Nov 2, 8:36 am, Nate Young youn...@gmail.com wrote: On 11/01/2011 03:05 PM, AndyK wrote: How would (run-tests 'my-namespace) know to run all thosedynamic tests? I thought that it parsed the namespace for 'my-namespace when you call it. Or is it that the call to defcsvtests sets off a chain of macro resolutions before run-tests can even do its thing (so that it Right. Its that the macro-expansion phase actually reads from the csv file in order to create a number of deftest forms, and each one then gets evaluated, so after you've evaluated (defcsvtests), then (run-tests) will be able to find a number of tests to run. -- 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 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: form-zip
(fz-node-seq x) is just (tree-seq coll? seq x)
Good Point! I had never noticed the parallels between tree-seq and
zippers, but it's obvious when you point it out. Thanks for
mentioning that.
(personally I don't have enough experience to be comfortable with
them),
yeah, i haven't found a great use case for zippers yet either. but
lately I've been experimenting with using them to write more readable
code transforms. hence the need for form-zip.
Like clojure.walk, but with the ability to backtrack.
fz-node-seq doesn't seem useful.
Ouch! Ok, here's one that is. As you astutely noted above,
fz-node-seq is functionally equivalent to (tree-seq coll? seq x), but
what's interesting about it is, it is implemented like so:
(map zip/node (fz-loc-seq form))
What's useful there is the call to fz-loc-seq which provides
a seq of every zipper loc in the form. Useful again for code
transforms, I think.
Thanks again for exercising my brain cells. I haven't forgotten that
beer I owe you.
On Nov 8, 8:06 pm, Alan Malloy a...@malloys.org wrote:
(fz-node-seq x) is just (tree-seq coll? seq x) then, yeah? I could see
form-zip being useful for people who like zippers (personally I don't
have enough experience to be comfortable with them), but fz-node-seq
doesn't seem useful.
On Nov 1, 8:56 pm, George Jahad cloj...@blackbirdsystems.net wrote:
surely this one's been written before, but i needed it the other day
and couldn't find it.
form-zip returns a zipper from a clojure form.
user= (require '[clojure.zip :as zip])
user= (use 'form-zip.core)
user= (- '{1 2 3 4} form-zip zip/next zip/remove zip/root)
{3 4}
fz-node-seq returns a seq of the nodes.
user= (fz-node-seq '{1 2 3 4})
({1 2, 3 4} [1 2] 1 2 [3 4] 3 4)
a one hour hack, probably full of edge cases i haven't thought of.
on clojars and github:https://github.com/GeorgeJahad/form-zip
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Re: Multiple try via macro
Hi, the loop is unnecessary in this case. You can just as well use let. And you may want to use an if with the (throw (Exception. nothing succeeded)) instead of the when. Sincerely Meikel -- 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: `conj` into maps
Right, a collection can implement cons however it likes. While it's convenient, I was just curious about the 'why' of APersistentMap's implementation, esp. since it overlaps w/ `merge`. - Chas On Nov 9, 2011, at 8:28 AM, Stuart Sierra wrote: It may relate to the implementation of IPersistentCollection.cons(Object). As far as I know, the IPersistentCollection.cons(Object) method powers the polymorphic behavior of the `conj` function, and is the foundation for the persistent collections in general. -S -- 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 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: SQL Korma Missing Pred
So it does, thanks! -- 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: Multiple try via macro
Thank you. Is loop and not for example let, for recursion optimalization? The primary purpose of the loop in this example is to indicate the local time where I am and therefore the absence of Mountiain Dew in my bloodstream. :-) Stu -- 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: using sqlite3
project.clj:
---
(defproject testsqlite 1.0.0-SNAPSHOT
:description FIXME: write description
:disable-deps-clean false
:dependencies [[org.clojure/clojure 1.3.0]
[org.clojure/clojure-contrib 1.2.0]
[org.clojure/java.jdbc 0.1.0]
[org.xerial/sqlite-jdbc 3.7.2]]
:main testsqlite.core)
core.clj:
---
(ns testsqlite.core
(:import [java.io File])
(:require [clojure.java.jdbc :as sql])
(:gen-class))
(def db-name test.db)
(def db {
:classname org.sqlite.JDBC
:subprotocol sqlite; Protocol to use
:subname db-name; Location of the db
})
(def new-db-conn (merge db {:create true}))
(defn create-tables
Creates the tables needed.
[]
(sql/create-table
:members
[:id :integer PRIMARY KEY]
[:name varchar(32)]
[:age :integer]
[:programmer tinyint]))
(defn insert-record
[name age programmer?]
(sql/insert-values
:members
[:name
:age
:programmer]
[name
age
programmer?]))
(defn get-records
[record-fn]
(sql/with-query-results
rs
[select * from members]
(doseq [r rs]
(record-fn r
(defn delete-record
[id]
(sql/delete-rows :members [id = ? id]))
(defn -main
[ args]
(when (not (.exists (File. db-name)))
(sql/with-connection new-db-conn
(create-tables)))
(cond (= (nth args 0) insert)
(sql/with-connection db
(insert-record (nth args 1)
(Integer/parseInt (nth args 2))
(Integer/parseInt (nth args 3
(= (nth args 0) dump)
(sql/with-connection db
(get-records println))
(= (nth args 0) delete)
(sql/with-connection db
(delete-record (Integer/parseInt (nth args 1
)
)
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Re: using sqlite3
Use this project.clj instead (eliminating the reference to clojure-contrib): (defproject testsqlite 1.0.0-SNAPSHOT :description FIXME: write description :disable-deps-clean false :dependencies [[org.clojure/clojure 1.3.0] [org.clojure/java.jdbc 0.1.0] [org.xerial/sqlite-jdbc 3.7.2]] :main testsqlite.core) -- 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: Dynamic test creation?
On Nov 9, 2011, at 8:37 AM, AndyK wrote: Questions about tabular tests... * can they take a lazy-seq as input? Do you mean something like having a computation that generates a stream of test inputs and feeds them into a test evaluator? If so, no: all `tabular's` work happens at compile/macroexpansion time. However, the underlying test-execution-and-reporting function is available and takes test descriptions as maps, so you could do something like (map midje.unprocessed/expect* (source-of-test-maps)) * will the tests be parallelized? (i have anywhere from 10k-20k tests to run) The code doesn't make any effort to parallelize tests. Tests are normally run as they're encountered at load time. (Unlike clojure.test, the `fact` macro doesn't stash a test-function away for later execution.) A test runner like the above should be parallelizable, though I didn't make any special effort to ensure that. The default reporter just prints results. You'd probably want one that stashes them away in an atom as they come in. There's already a way to swap in different reporters, so that shouldn't be too hard. More discussion should probably happen at http://groups.google.com/group/midje - Brian Marick, Artisanal Labrador Now working at http://path11.com Contract programming in Ruby and Clojure Occasional consulting on Agile -- 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: NullPointerException in c.l.Compiler.lookupVar after aot compilation: means what?
On Nov 8, 2011, at 6:44 PM, Stuart Halloway wrote: Line 4 of midje.util.report is unusual in several ways: it precedes the ns call, adds a second ns call, does an eval, and uses def forms not at the top level: Thanks, Stu. That code was a patch that came in when I was new to Clojure, and I didn't understand it. I think it was a workaround for something in Clojure 1.1. I bet I can figure it out now. - Brian Marick, Artisanal Labrador Now working at http://path11.com Contract programming in Ruby and Clojure Occasional consulting on Agile -- 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 on the reversim podcast
Iv been hosted on reversim (an Israeli software podcast) for a talk about Clojure, The talk is in Hebrew: http://www.reversim.com/ Ronen -- 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
core.logic questions
I'm working through the core.logic examples on http://objectcommando.com.
I want to develop a query that returns the child and his parents. The
gives me what I want:
(run* [q]
(fresh [m f c]
(== c 'Sonny)
(parent m c)
(parent f c)
(!= m f)
(== q {:child c :parents [m f]})))
I'd like to create a re-usable function for parent-of, so I have:
(defn parents-of [m f c]
(parent m c)
(parent f c)
(!= m f))
(run* [q]
(fresh [m f c]
(== c 'Sonny)
(parents-of m f c)
(== q {:child c :parents [m f]})))
produces ({:child Sonny, :parents [_.0 _.1]})
I'm obviously missing something about what I'm actually defining in the
defn but I'm struggling to figure out what it is.
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REPL magic: get the previous expression?
Does anyone know how to programmatically get the previous expression entered at the REPL? You can get it interactively by pressing the up- arrow key; and of course you can get the previous \result through the variable *1. Is there any similar variable or function (perhaps in Java-land) that would give you the previous \expression? Thanks, Nick. -- 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: core.logic questions
Functions that are going to be used in core logic must return goals. (defn parents-of [m f c] (parent m c) (parent f c) (!= m f)) In this case you only return the (!= m f) subgoal instead of the goal that represents the conjunction of all three subgoals. (defn parents-of [m f c] (all (parent m c) (parent f c) (!= m f))) Is probably what you want. Untested. David -- 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
Open source Clojure projects
For many of the older languages I look at, there are big open source projects that people are working on that are making a big impact. C has linux, Javascript has jQuery and Khan Academy's frameworks, Java has their libraries, etc. etc. Are there any Clojure projects I could contribute to? I know new ideas are being developed all the time, I can see them cropping up on here everyday. It seems like by the time I hear about it, they are implemented already and most of the bugs have been sussed out though. Besides hacking on clojure itself, there doesn't seem like there are any projects I could add to (and I would have to learn way more to be able to contribute anything useful with the clojure code). -Zack -- 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: Open source Clojure projects
Whenever I see a question like this asked anywhere (and even when I ask the question to myself or others) I usually recommend reading (or read myself): http://prog21.dadgum.com/80.html :) U -- 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
sqlitejdbc jar on clojars
sqlite3 had some problems but a later version (3.7.9) seems to work. Now the sqlitejdbc jar on clojars version 0.5.6 has the same problems as the old sqlite3 command line. Basically, I get this error below when reading certain .sqlite files. Is there a latest version of the sqlitejdcb driver for clojure? cljstudent.sqlite= (get-data) java.sql.SQLException: file is encrypted or is not a database (NO_SOURCE_FILE:0 -- 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: REPL magic: get the previous expression?
What do you mean? If it's programatically then why not use a loop or something? -- 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: `conj` into maps
I expect you're right: it's vestigial. -S -- 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: sqlitejdbc jar on clojars
I'm using the sqlite-jdbc jar from a maven repository. I use this in my leiningen project to fetch it: [org.xerial/sqlite-jdbc 3.7.2] I haven't had any issues with it, but that doesn't mean you won't. On Nov 9, 12:50 pm, labwor...@gmail.com wrote: sqlite3 had some problems but a later version (3.7.9) seems to work. Now the sqlitejdbc jar on clojars version 0.5.6 has the same problems as the old sqlite3 command line. Basically, I get this error below when reading certain .sqlite files. Is there a latest version of the sqlitejdcb driver for clojure? cljstudent.sqlite= (get-data) java.sql.SQLException: file is encrypted or is not a database (NO_SOURCE_FILE:0 -- 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: REPL magic: get the previous expression?
I mean I want to write a utility that has access to the previous expression entered at the REPL no matter where this utility is called. Since the up-arrow key has this access, it must be possible On Nov 9, 12:57 pm, Michael Beattie mtbee...@gmail.com wrote: What do you mean? If it's programatically then why not use a loop or something? -- 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: REPL magic: get the previous expression?
The up-arrow key can recall the expressions you send thanks to either readline or Leiningen. You might be able to hook the appropriate var in leiningen.repl in order to slip your own function into the options passed to the Clojure REPL it starts. You need to be able to intercept the form being evaluated so you can store it off somewhere (either in a var via set! or otherwise). Interesting idea. Maintaining command history on the server side of the REPL (i.e. more than just having *!1, *!2, *!3 [or whatever]) might have some good use cases in general. - Chas On Nov 9, 2011, at 1:25 PM, nchurch wrote: I mean I want to write a utility that has access to the previous expression entered at the REPL no matter where this utility is called. Since the up-arrow key has this access, it must be possible On Nov 9, 12:57 pm, Michael Beattie mtbee...@gmail.com wrote: What do you mean? If it's programatically then why not use a loop or something? -- 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 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: NullPointerException in c.l.Compiler.lookupVar after aot compilation: means what?
On Nov 8, 2011, at 8:47 PM, Alan Malloy wrote: (let [ns-obj (the-ns (doto 'clojure.test require)) the-var (intern ns-obj 'old-report)] (when-not (.hasRoot the-var) (intern ns-obj 'old-report clojure.test/report))) Seems to have the same effect as the defonce in some simple testing. Of course it's silly to use intern the second time: (.setRoot the-var clojure.test/report) would have been simpler. Thank you. You've made a user happy. (You meant .bindRoot rather than .setRoot, right?) - Brian Marick, Artisanal Labrador Now working at http://path11.com Contract programming in Ruby and Clojure Occasional consulting on Agile -- 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: Open source Clojure projects
There are lots. You could start browsing from here: https://github.com/languages/Clojure - Chris -- 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: Dynamic test creation?
On 11/08/2011 12:44 PM, AndyK wrote: I finally had a chance to try this out and it fails with error: java.lang.ClassCastException: java.lang.String cannot be cast to clojure.lang.IObj Compilation failed. I think I fat-fingered my deftest-form definition: I originally wrote: (defn testdef-form [n [expected actual]] `(deftest ~(str testfromline n) (is (= ~expected ~actual But it should probably be: (defn testdef-form [n [expected actual]] `(deftest ~(symbol (str testfromline n)) (is (= ~expected ~actual The original, wrong, function would have produced something like this: (deftest testfromline27 (is (= 5 2))) Which is probably what's giving you the error message you're seeing. That string should be a symbol: (deftest testfromline27 (is (= 5 2))) When I substituted in something like this... (defn prn-form [n scenario] `(prn ~(str foo n) (prn ~(str n :: scenario the file did compile. I'd have to see the rest of your code to comment on what's going on here. Is the fact that deftest is also a macro going to cause a problem with the original idea? Macros certainly have composability issues, but its certainly safe to write a macro that produces some other macro form. In fact, lots of clojure.core macros use this to great effect (affect?), see -, cond, or, and .. to name a few. -- 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: Re: sqlitejdbc jar on clojars
Thanks but I am not getting anything with it. Here's what I have. Does it
seem correct?
(ns cljstudent.sqlite
(:require [clojure.contrib.sql :as sql]))
;; need this to load the sqlite3 driver (as a side effect of evaluating the
expression)
;;(Class/forName org.sqlite.JDBC)
(def db-path /home/melipone/cljstudent/places.sqlite)
(def db-specs {:classname org.sqlite.JDBC,
:subprotocol sqlite,
:subname db-path})
(def db-query select * from moz_places where visit_count 100)
(defn get-data []
(sql/with-connection db-specs
(sql/with-query-results results [db-query]
(doall results
On , willyh wheine...@gmail.com wrote:
I'm using the sqlite-jdbc jar from a maven repository. I use this in
my leiningen project to fetch it:
[org.xerial/sqlite-jdbc 3.7.2]
I haven't had any issues with it, but that doesn't mean you won't.
On Nov 9, 12:50 pm, labwor...@gmail.com wrote:
sqlite3 had some problems but a later version (3.7.9) seems to work. Now
the sqlitejdbc jar on clojars version 0.5.6 has the same problems as the
old sqlite3 command line. Basically, I get this error below when reading
certain .sqlite files. Is there a latest version of the sqlitejdcb
driver
for clojure?
cljstudent.sqlite= (get-data)
java.sql.SQLException: file is encrypted or is not a database
(NO_SOURCE_FILE:0
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Re: Re: sqlitejdbc jar on clojars
Sorry, I had my query wrong. This driver does work now. Thanks! On , willyh wheine...@gmail.com wrote: I'm using the sqlite-jdbc jar from a maven repository. I use this in my leiningen project to fetch it: [org.xerial/sqlite-jdbc 3.7.2] I haven't had any issues with it, but that doesn't mean you won't. On Nov 9, 12:50 pm, labwor...@gmail.com wrote: sqlite3 had some problems but a later version (3.7.9) seems to work. Now the sqlitejdbc jar on clojars version 0.5.6 has the same problems as the old sqlite3 command line. Basically, I get this error below when reading certain .sqlite files. Is there a latest version of the sqlitejdcb driver for clojure? cljstudent.sqlite= (get-data) java.sql.SQLException: file is encrypted or is not a database (NO_SOURCE_FILE:0 -- 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 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: REPL magic: get the previous expression?
My particular use-case was to be able to write tests for things entered at the REPL. I'm almost done with a basic version of it and will post it to the list when done. It would be much easier if the expressions were there anyway. I guess the issue is that people may not always be using Lein or Readline; they may be in Eclipse, Netbeans, etc., which have their own REPLS. Considering all that it might make sense to just ask the user to launch a subrepl, which would be both more robust and easier to implement. I did look at lein.repl, thanks for the pointer! -- 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: Creating a var, functions from a macro
Apparently the missing bit is I need to escape the symbol calls, e.g. (defn ~(symbol index) ... Is this correct? -- 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
All subsets of a vector
Is there a more elegant/idomatic way to achieve the following result: user= a1 [a b c d] user= (map-indexed (fn [n x] (vec (take (inc n) x))) (take (count a1) (repeat a1))) ([a] [a b] [a b c] [a b c d]) -- 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: All subsets of a vector
(map #(vec (take (inc %) a1)) (range (count a1))) does it the lovely map. /Linus 2011/11/9 Shoeb Bhinderwala shoeb.bhinderw...@gmail.com Is there a more elegant/idomatic way to achieve the following result: user= a1 [a b c d] user= (map-indexed (fn [n x] (vec (take (inc n) x))) (take (count a1) (repeat a1))) ([a] [a b] [a b c] [a b c d]) -- 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 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: NullPointerException in c.l.Compiler.lookupVar after aot compilation: means what?
Line 4 of midje.util.report is unusual in several ways: it precedes the ns call, adds a second ns call, does an eval, and uses def forms not at the top level: Thanks, Stu. That code was a patch that came in when I was new to Clojure, and I didn't understand it. I think it was a workaround for something in Clojure 1.1. I bet I can figure it out now. Let me know if you don't find a workaround -- I would still like to understand that NPE. Stu Stuart Halloway Clojure/core http://clojure.com -- 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 of a newbie
Very hard question to answer. It makes sense that static typing would help, but in practice I never seem to get defects that are related to types. Ergo, Clojure's approach to typing works well, and the code stays very minimalist. On Nov 8, 2011 12:52 AM, Sean Corfield seancorfi...@gmail.com wrote: On Mon, Nov 7, 2011 at 4:20 AM, Dennis Haupt d.haup...@googlemail.com wrote: which is a good thing. type safety is good. Is it? -- Sean A Corfield -- (904) 302-SEAN An Architect's View -- http://corfield.org/ World Singles, LLC. -- http://worldsingles.com/ Perfection is the enemy of the good. -- Gustave Flaubert, French realist novelist (1821-1880) -- 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 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: All subsets of a vector
Does Clojure have the equivalent of Haskell's 'scan' function? (I am on my phone...) Seems like a solution with that would be nice. (scan is like reduce except it keeps all intermediate results) On Nov 9, 2011 5:57 PM, Linus Ericsson oscarlinuserics...@gmail.com wrote: (map #(vec (take (inc %) a1)) (range (count a1))) does it the lovely map. /Linus 2011/11/9 Shoeb Bhinderwala shoeb.bhinderw...@gmail.com Is there a more elegant/idomatic way to achieve the following result: user= a1 [a b c d] user= (map-indexed (fn [n x] (vec (take (inc n) x))) (take (count a1) (repeat a1))) ([a] [a b] [a b c] [a b c d]) -- 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 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 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: All subsets of a vector
Another way to do it, using 'reductions': (rest (reductions conj [] a1)) On Wednesday, November 9, 2011 5:47:08 PM UTC-5, Shoeb Bhinderwala wrote: Is there a more elegant/idomatic way to achieve the following result: user= a1 [a b c d] user= (map-indexed (fn [n x] (vec (take (inc n) x))) (take (count a1) (repeat a1))) ([a] [a b] [a b c] [a b c d]) -- 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: All subsets of a vector
That's exactly what 'reductions' does :) On Wednesday, November 9, 2011 6:09:08 PM UTC-5, Alex Baranosky wrote: Does Clojure have the equivalent of Haskell's 'scan' function? (I am on my phone...) Seems like a solution with that would be nice. (scan is like reduce except it keeps all intermediate results) On Nov 9, 2011 5:57 PM, Linus Ericsson oscarlinu...@gmail.com wrote: (map #(vec (take (inc %) a1)) (range (count a1))) does it the lovely map. /Linus 2011/11/9 Shoeb Bhinderwala shoeb.bh...@gmail.com Is there a more elegant/idomatic way to achieve the following result: user= a1 [a b c d] user= (map-indexed (fn [n x] (vec (take (inc n) x))) (take (count a1) (repeat a1))) ([a] [a b] [a b c] [a b c d]) -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clo...@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+u...@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 post to this group, send email to clo...@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+u...@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 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: NullPointerException in c.l.Compiler.lookupVar after aot compilation: means what?
On Nov 9, 2011, at 4:58 PM, Stuart Halloway wrote: Line 4 of midje.util.report is unusual in several ways: it precedes the ns call, adds a second ns call, does an eval, and uses def forms not at the top level: Thanks, Stu. That code was a patch that came in when I was new to Clojure, and I didn't understand it. I think it was a workaround for something in Clojure 1.1. I bet I can figure it out now. Let me know if you don't find a workaround -- I would still like to understand that NPE. It's all better now. Alan Malloy's fix worked fine on Clojure 1.2.1 and 1.3. - Brian Marick, Artisanal Labrador Now working at http://path11.com Contract programming in Ruby and Clojure Occasional consulting on Agile -- 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: All subsets of a vector
Dang, I just logged in in-flight just so I could post my solution with reductions :) (defn doit [coll] (rest (reductions conj [] coll))) -- 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: All subsets of a vector
Or my current favorite take-while iterate combo: C:\clojure-1.2.0java -jar clojure.jar Clojure 1.2.0 user= (take-while seq (iterate rest [1 2 3 4])) ([1 2 3 4] (2 3 4) (3 4) (4)) user= (take-while seq (iterate butlast [1 2 3 4])) ([1 2 3 4] (1 2 3) (1 2) (1)) user= On Nov 9, 4:52 pm, Alex Baranosky alexander.barano...@gmail.com wrote: Dang, I just logged in in-flight just so I could post my solution with reductions :) (defn doit [coll] (rest (reductions conj [] coll))) -- 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
Must PersistentQueue be stored in ref not atom?
Hi, To avoid peeking same element of a queue, I think PersistentQueue must be stored in ref not atom. Is this correct? ;;Ref: safe (dosync (let [item (peek @r)] (alter r pop) item)) ;Atom: unsafe (let [item (peek @a)] (swap! a pop) item)) Thanks. -- 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: Must PersistentQueue be stored in ref not atom?
In your example yes, but you could make it atomic by placing the functionality in a function of it's own: ;; queue processing actions (defn process-item [queue] (println Processed item: (peek queue)) (pop queue)) ;; usage (let [queue (atom (into PersistentQueue/EMPTY [1 2 3]))] (swap! queue process-item) ; prints 1 (swap! queue process-item) ; prints 2 (swap! queue process-item)) ; prints 3 Probably better examples but that's the basic idea. Allen On Wed, Nov 9, 2011 at 8:46 PM, Takahiro Hozumi fat...@googlemail.com wrote: Hi, To avoid peeking same element of a queue, I think PersistentQueue must be stored in ref not atom. Is this correct? ;;Ref: safe (dosync (let [item (peek @r)] (alter r pop) item)) ;Atom: unsafe (let [item (peek @a)] (swap! a pop) item)) Thanks. -- 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 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: Must PersistentQueue be stored in ref not atom?
I see! Thank you. 2011/11/10 Allen Johnson akjohnso...@gmail.com: In your example yes, but you could make it atomic by placing the functionality in a function of it's own: ;; queue processing actions (defn process-item [queue] (println Processed item: (peek queue)) (pop queue)) ;; usage (let [queue (atom (into PersistentQueue/EMPTY [1 2 3]))] (swap! queue process-item) ; prints 1 (swap! queue process-item) ; prints 2 (swap! queue process-item)) ; prints 3 Probably better examples but that's the basic idea. Allen On Wed, Nov 9, 2011 at 8:46 PM, Takahiro Hozumi fat...@googlemail.com wrote: Hi, To avoid peeking same element of a queue, I think PersistentQueue must be stored in ref not atom. Is this correct? ;;Ref: safe (dosync (let [item (peek @r)] (alter r pop) item)) ;Atom: unsafe (let [item (peek @a)] (swap! a pop) item)) Thanks. -- 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 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 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: Must PersistentQueue be stored in ref not atom?
Although now I see that this usage is breaking the side-effect free rule. So actually this is probably not what you want to do. :) Now I'm with you and thinking that atoms are not a proper fit for PersistentQueue. Maybe someone from the conj can shed some light on this. Allen On Wed, Nov 9, 2011 at 8:56 PM, Allen Johnson akjohnso...@gmail.com wrote: In your example yes, but you could make it atomic by placing the functionality in a function of it's own: ;; queue processing actions (defn process-item [queue] (println Processed item: (peek queue)) (pop queue)) ;; usage (let [queue (atom (into PersistentQueue/EMPTY [1 2 3]))] (swap! queue process-item) ; prints 1 (swap! queue process-item) ; prints 2 (swap! queue process-item)) ; prints 3 Probably better examples but that's the basic idea. Allen On Wed, Nov 9, 2011 at 8:46 PM, Takahiro Hozumi fat...@googlemail.com wrote: Hi, To avoid peeking same element of a queue, I think PersistentQueue must be stored in ref not atom. Is this correct? ;;Ref: safe (dosync (let [item (peek @r)] (alter r pop) item)) ;Atom: unsafe (let [item (peek @a)] (swap! a pop) item)) Thanks. -- 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 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: Must PersistentQueue be stored in ref not atom?
I see. You are right. A function passed to swap! must return only poped value, so peeked element from a queue is used only for side-effect in the function. 2011/11/10 Allen Johnson akjohnso...@gmail.com: Although now I see that this usage is breaking the side-effect free rule. So actually this is probably not what you want to do. :) Now I'm with you and thinking that atoms are not a proper fit for PersistentQueue. Maybe someone from the conj can shed some light on this. Allen On Wed, Nov 9, 2011 at 8:56 PM, Allen Johnson akjohnso...@gmail.com wrote: In your example yes, but you could make it atomic by placing the functionality in a function of it's own: ;; queue processing actions (defn process-item [queue] (println Processed item: (peek queue)) (pop queue)) ;; usage (let [queue (atom (into PersistentQueue/EMPTY [1 2 3]))] (swap! queue process-item) ; prints 1 (swap! queue process-item) ; prints 2 (swap! queue process-item)) ; prints 3 Probably better examples but that's the basic idea. Allen On Wed, Nov 9, 2011 at 8:46 PM, Takahiro Hozumi fat...@googlemail.com wrote: Hi, To avoid peeking same element of a queue, I think PersistentQueue must be stored in ref not atom. Is this correct? ;;Ref: safe (dosync (let [item (peek @r)] (alter r pop) item)) ;Atom: unsafe (let [item (peek @a)] (swap! a pop) item)) Thanks. -- 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 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 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
should partial accept a single argument?
I'm curious why something like (partial *) doesn't work. reading the docstring, user (doc partial) - clojure.core/partial ([f arg1] [f arg1 arg2] [f arg1 arg2 arg3] [f arg1 arg2 arg3 more]) Takes a function f and fewer than the normal arguments to f, and returns a fn that takes a variable number of additional args. When called, the returned function calls f with args + additional args. It seems like fewer than the normal arguments to f could reasonably include 0 arguments. why not have (partial f) return f? it would be consistent with (* n) == n, (+ n) == n etc, and would help when using partial recursively. sincerely, --Robert McIntyre -- 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
smallest unit of code requiring a CA
Hi, I have a patch to the clojure compiler that I would like to submit. I haven't signed a CA, but the patch is quite small. Would it be possible to submit it without a CA? I have no objection to signing one; it would just be slightly embarassing to do so for such a small patch. :) The patch is at https://github.com/chrismgray/clojure/tree/namespace-divides and simply allows code to refer to the / function in namespaces other than clojure.core. Cheers, Chris -- 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: Must PersistentQueue be stored in ref not atom?
Hi, an atom can be sufficient, but you need to drop to a lower level. (defn !paws Like swap! but returns the old value of the atom. [a f args] (loop [] (let [old-value @a new-value (apply f old-value args)] (if (compare-and-set! a old-value new-value) old-value (recur) (peek (!paws atom-with-queue pop)) However, my suspicion is, that you don't clearly divide the state handling from the program logic. The peek should happen in the update function you pass to swap!. If this is not side-effect free, it means that you have to coordinate with other identities and resources. Then a ref or an agent might be indeed a better fit than the atom. Sincerely Meikel -- 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: smallest unit of code requiring a CA
Chris Gray wrote: I have a patch to the clojure compiler that I would like to submit. I haven't signed a CA, but the patch is quite small. Would it be possible to submit it without a CA? I have no objection to signing one; it would just be slightly embarassing to do so for such a small patch. :) The patch is at https://github.com/chrismgray/clojure/tree/namespace-divides and simply allows code to refer to the / function in namespaces other than clojure.core. FWIW, I'd just go ahead and sign the CA. Regardless of how small you might perceive this particular patch to be, you may very well find yourself submitting additional patches in the future. Also, 100% conjecture on my part, but I'd assume the CA isn't about the size of the patch, but general protection for the core group that needs to be in place whether the accompanying patch is one line, one page, or one character. -- 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
