Re: Infinite sequences hang sets and maps
On Wed, Oct 28, 2009 at 9:35 PM, Alex Osborne a...@meshy.org wrote: John Harrop wrote: Probably the seq .hashCode should consider only the first N elements for some maximum N and if two longer (or even infinite) sequences collide so be it. I strongly disagree. Choosing some arbitrary magic cutoff point just seems cause for trouble and much confusion. For the specific case of hashCode, no; identical values must have identical hashes but different values need not have different hashes. Collisions due to the hypothetical cutoff get exponentially less likely with each additional increment of 1 of the cutoff length. You're right though that they still won't work in hashmaps and hashsets because the equals test will hang when the sequences are actually equal. This also stops them working in treemaps and treesets (even if we added Comparable to ISeq to use lexicographic order and comparisons of the elements, or supplied a comparator that did so; and even if the seq-compare function gave up after N identical pairs of elements, resulting in hash collisions). A workaround if you want to index something by infinite (or just very large) seqs might be to use (take n the-seq) for some constant n chosen large enough for the truncated sequences to tend not to collide in practice, with some contingency for the case of collisions. --~--~-~--~~~---~--~~ 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: Constructing Java Interop calls
On Wed, Oct 28, 2009 at 10:15 PM, Alex Osborne a...@meshy.org wrote: Tiago Antão wrote: Again, the point here is to be able to construct method names (full call signatures, really) on runtime. I am lost. As in newbie clueless :( As others have suggested you need to use either Java's reflection or Clojure's eval. Not quite -- this works as long as the Bla part is a constant: (defmacro setProperty [field obj value] (let [cct (symbol (.concat .set (str field)))] `(~cct ~obj ~value))) user= (macroexpand-1 '(setProperty Bla x 1)) (.setBla x 1) --~--~-~--~~~---~--~~ 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: ANN: Clojure live-repl
I think it would be great if JLine is integrated in live-repl. I have some questions: * Why not use maven and clojure-maven-plugin? * Is it OK if live-repl uses one version of Clojure and the attached process uses another? On Oct 29, 9:35 am, David Powell djpow...@djpowell.net wrote: Under Linux I had to fix the paths in liverepl.sh to include the build folder: java -cp $LIVEREPL_HOME/build/*:$JDK_HOME/lib/tools.jar net.djpowell.liverepl.client.Main $CLOJURE_JAR $LIVEREPL_HOME/build/liverepl-agent.jar $LIVEREPL_HOME/build/liverepl-server.jar $@ I think liverepl.sh gets copied to the build folder, so the intent is to run that copy of the liverepl.sh script. (Though I haven't really tested the .sh script) -- Dave --~--~-~--~~~---~--~~ 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: Infinite sequences hang sets and maps
Hello, On Thu, Oct 29, 2009 at 3:35 AM, Alex Osborne a...@meshy.org wrote: John Harrop wrote: Probably the seq .hashCode should consider only the first N elements for some maximum N and if two longer (or even infinite) sequences collide so be it. I strongly disagree. Choosing some arbitrary magic cutoff point just seems cause for trouble and much confusion. Putting something in a hash set or using it as a map key implies evaluating it -- you'd expect summing or printing an infinite sequence to hang, so why shouldn't hashing it also hang? +1, I also disagree. If there is a need to compare parts of infinite sequences, just truncate them and compare the resulting finite parts. This is something that belongs in the application, not in the language, as the value for N depends on the application and there is no N that fits everyone (other than infinity). -- Miron Brezuleanu --~--~-~--~~~---~--~~ 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: Infinite sequences hang sets and maps
John Harrop wrote: On Wed, Oct 28, 2009 at 9:35 PM, Alex Osborne wrote: Choosing some arbitrary magic cutoff point just seems cause for trouble and much confusion. For the specific case of hashCode, no; identical values must have identical hashes but different values need not have different hashes. Collisions due to the hypothetical cutoff get exponentially less likely with each additional increment of 1 of the cutoff length. Yeah, that's true, but I meant in the usual context where you fall back to equality in the event of a collision (like, as you say, sets and maps). I think it would be very confusing if when you put an infinite sequence in one set it works (because there's no collision so it uses the cutoff) while putting the exact same sequence in a different set it hangs (because of a collision it falls back to equality). I can imagine that being a nightmare to debug particularly because in most programs it will only happen very rarely. --~--~-~--~~~---~--~~ 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: Infinite sequences hang sets and maps
On Wed, Oct 28, 2009 at 11:08 PM, John Harrop jharrop...@gmail.com wrote: For the specific case of hashCode, no; identical values must have identical hashes but different values need not have different hashes. Collisions due to the hypothetical cutoff get exponentially less likely with each additional increment of 1 of the cutoff length. I see your point that hashCode could be made to work on infinite sequences, but since hashing is almost always a prelude to testing for equality, I'm hard pressed to think of an example of why you'd want to be able to do this. Can you illustrate with an example? --~--~-~--~~~---~--~~ 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: Scientific computing
On 28 Oct 2009, at 22:21, Rock wrote: Your analysis is crystal clear and very helpful Konrad. But you haven't addressed the issue of dealing with useful information regarding the data structure itself. What if, for example, a function wanted to know the rank and dimensions of a multidimensional array it was being passed, and that array were represented by means of a nested vector? I didn't address such issues because there is no point in discussing them before making the fundamental decision whether to use an abstract or an exposed data type for array data. That choice dictates the priorities for everything that follows. Suppose we're dealing with rank n objects. Do you think it would be an easy task to figure all that out dealing with nested vectors? If you can assume the array is well-formed, it is rather easy. Otherwise it isn't. And by the way, How would you go about implementing in detail a check to see if a nested vector is actually an authentic multidimensional array or not? That's a rather simple recursive function. The only problem is its run- time cost. I honestly prefer your first case scenario. Seems much more efficient, less resource-consuming, and just straightforward. But I really would like to know what your preference is. If you had to choose, which way would you go? If I were to design an array interface for Clojure, it would consist of multimethods implemented for both an efficient array data structure for internal use and for nested vectors. The implementation for the latter would convert the nested vectors to the efficient structure and do all the necessary checks. It would be there for convenience and clarity in user code. Ideally I would then implement the same interface for Colt arrays and netCDF arrays as well, both for having an effcient structure for large data sets and for interoperability. And once we are at it, why not have another implementation for sparse arrays, using a suitable data structure? Unfortunately, a good design and implementation represents a lot of work. At the moment I am not sure if we have the critical mass of people interested in working on this to get the job done in a reasonable amount of time. On 28 Oct 2009, at 23:07, harrison clarke wrote: maps could also be an option. you can use vectors of ints as keys. (and you can stick dimensions and such in there with keywords) i'm not sure how that compares to nested vectors for perforance. you have the overhead of the hash function, but you don't have any nesting. it's also pretty handy if you want to represent a sparse matrix. Maps could be a good choice for sparse arrays. For dense ones, they would represent an enormous waste of memory, and probably time as well. Konrad. --~--~-~--~~~---~--~~ 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 QuickLook for Mac OS X?
Hi there! Has anyone been able to use QuickLook wich Clojure source files? Regards, Per --~--~-~--~~~---~--~~ 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: Embedding Clojure in NetKernel
Do you mind sharing the links? I am interested in it as well. Thanks! Roman 2009/10/28 Tony Butterfield t...@1060.org: Tom Hicks has just pointed me to an old thread which answers questions about namespaces and isolation. Let me read and absorb all that work first - I suspect it answers a lot of my questions. Cheers, Tony On Oct 28, 11:43 am, Tony Butterfield t...@1060.org wrote: Hi Everybody this is my first post to this group so please tell me If I'm posting in the wrong place. I've been looking at integrating Clojure into NetKernel as language runtime library but I'm struggling a bit for a lack of examples. There are two things I'm trying to achieve: 1) start and stop the Clojure runtime on demand. I need to do this so that new versions can be deployed whilst the server is live. Looking at the latest version (1.0.0) I see that I no longer need to call RT.init() and that startup is done statically. That's fine but is there a way to cleanly shutdown. I.e. stop threads, and enable a full garbage collection of the Clojure libraries? 2) is there a way to ensure isolation of functionality in one runtime? I can see how I can use namespaces to avoid naming collisions but is it possible to enforce tighter security across namespaces or is there another technique? I'm quite new to closure so sorry if that is a stupid question - the trouble is I want to get it running inside NetKernel as good environment to explore the language - horse before the cart! When Clojure scripts execute inside NetKernel environment it is important that they act like pure functions with no side-effects on others. Thanks in advance for you advice, Tony --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~--~~~~--~~--~--~---
Re: Clojure QuickLook for Mac OS X?
On 29.10.2009, at 10:30, perdalum wrote: Has anyone been able to use QuickLook wich Clojure source files? I use the QLColorCode plugin (version 2.02): http://code.google.com/p/qlcolorcode/ To make it treat Clojure files (*.clj) like Lisp source code, open the Info.plist file in the package using the property list editor and open the item Imported Type UTIs. You should find an item called org.n8gray.lisp, it's number 17 in my configuration. Open it and click on Equivalent Types followed by public.filename-extension. Add a row containing clj. Log out and in again - and enjoy QuickLook on Clojure code! Konrad. --~--~-~--~~~---~--~~ 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: cannot cast error java char-array to java string
Yes, they both work - and the #^chars is much more legible. Many thanks! FYI, to whom it may concern...I think it's worth noting that this simple case gives confusing output from the repl. user= (new String #^chars (make-array Character/TYPE 3)) user= And this: user= (def asdf (new String #^chars (make-array Character/TYPE 3))) #'user/asdf user= asdf That's the exact output except for the indentation. The dangling string w/ its single double-quote followed by the prompt. The prompt is not even displayed w/ the second example. As you can see from this example, non-empty strings are displayed as expected. user= (def qwer (let [x (make-array Character/TYPE 3 )] (aset x 0 \a) (aset x 1 \b) (aset x 2 \c) (new String #^chars x))) #'user/qwer user= qwer abc CHICKEE On Oct 28, 10:31 pm, ataggart alex.tagg...@gmail.com wrote: Also you can substitute #^[C with the more legible #^chars. On Oct 28, 7:27 pm, Alex Osborne a...@meshy.org wrote: Chick Corea wrote: What is wrong with this code? I want to instantiate a Java String from a Java character-array. But I want it to be fast, hence the need to cast per the warn on reflection message. user= (set! *warn-on-reflection* true) true user= (new String #^[C (make-array Character/TYPE 3 \a )) java.lang.ClassCastException: [[C cannot be cast to [C (NO_SOURCE_FILE:0) Note the exception, [[C means a two-dimensional arary. (make-array Character/TYPE 3 \a) actually means (make-array Character/TYPE 3 97) so a 3 by 97 two-dimensional array (new char[3][97] in java syntax). What you probably want is: user (String. #^[C (into-array Character/TYPE (repeat 3 \a))) aaa --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~--~~~~--~~--~--~---
Re: Clojure in a big Java solution
Ok thanks for the answer :) I have now began to implement the Java parts. The data that is going to be processed in Clojure is mapped to clojure structs, but I now have another question. How should I update the values in the structs? Since functions are going to run in parallel and a function may need the updated value from another function I though that I should put the struct members that is going to be updated in refs or maybe atoms. Is this a good way or how should I manage the updated values in structs? Thanks :) On Oct 26, 4:11 pm, Shantanu Kumar kumar.shant...@gmail.com wrote: You can probably settle for a set ofJavadata structures that are inter-operable withClojure. 1. Use interfaces (becauseClojureimplements them too) such asjava.util.List,java.util.Set,java.util.Map etc. 2. Use type hints and enable warn on reflection. 3. When inClojure, first convert toClojuredata structure before doing any processing. 4. Try to minimize the cross-section surface area that connects theJavaandClojureparts and keep it clean. This may not answer all of your questions (such as concurrency), but I coded something inJava+Clojure, and the result I guess is pretty good. URL below: Taimen --http://code.google.com/p/bitumenframework/ Regards, Shantanu On Oct 26, 12:55 pm, vanallan vanal...@gmail.com wrote: Hi thanks for the replies :) The whole system consists of a couple of hundreds of thousands lines ofJavacode. The part i am investigating is a validation sub system that validates a number of input parameters given from the user against various predefined values and rules, and against databases and such. These methods don't just validate the input, they also set up a couple of objects based on the input given. I want these methods to run its own task in parallel, but sequential to the rest of the system. The reason i am doing this is to see if there is some improvements in performance and to see if it is possible at all to implement parts of abigsystem in a functional language. The same object is sent as an argument to all methods, and this object consist of a lot of other objects. On Oct 24, 5:54 pm, eyeris drewpvo...@gmail.com wrote: It's difficult to provide advice without more information about your current code. You say that you want a part of your system, which manipulates a lot of objects, to run in parallel. Do you mean that you want this part of the system to run parallel to the other parts -or- do you mean that this part will remain in sequence with the other parts of the system, but it will run its own tasks in parallel? Furthermore, what do you expect to gain from the parallelism? If it's simple divide-and-conquer parallelism to process a chunk of data faster, then that is pretty easy to implement inJava, so long as the data is dividable. On the other hand, if you want this part of your system to run in parallel with the other parts, then there's a wide spectrum ofClojure/Javamixes that could make sense. Like I said above, we'll need much more information before we can provide any valuable advice. On Oct 23, 7:41 am, vanallan vanal...@gmail.com wrote: Hi! I am currently investigating if it is possible to convert a part of a bigJavasystem toClojure. The reason for this is to make this part run in parallel and hence ease the implementation by porting it to Clojure. The problem is that these parts of the system is today setting and changing a lot mutable data in a lot of different objects. Which approach do you think i should have when i try to port these Javamethods? Should i try to retain theJavastructure and change these objects or is it better to create my own data structure and somehow manage them? Does anyone have any experience in integrating Clojurein abigJavasolution? Also i should mention that i'm quite new toClojure, and functional programming overall. :) 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 -~--~~~~--~~--~--~---
Scriptjure, Parenscript - why not generate code in other languages
Hi, earlier today I was wondering about the best way to write some Transact-SQL code. I normally write code in C#, Python and lately Clojure. Even though TSQL is a decent procedural extension to SQL, it still feels very cumbersome to the languages I use daily. Having done some C# code generation lately (using ScriptTemplate), I was thinking about doing the same thing for SQL. At which point I remembered Scriptjure (and Parenscript) and thought about writing something similar for TSQL. Google didn't reveal any already written such generators - I guess I'll have to come up with one, which I expect to be kind of fun. The bigger question is, why isn't this way (generate a Lisp datastructure that describes in a convenient way the syntax tree of the code to emit, then emit the actual code by walking the datastructure) of abstracting away syntax problems in programming languages more common? I can understand why it's not available for C# - losing code completion is a big disadvantage, but what about (T)SQL and others? Or it is actually an often used trick, but the tools used are written 'in-house' and not made public? I'll be very grateful for any input on the pros and cons of such an approach. The pros I see are the ability to construct the data structure using all the tools Clojure/Lisp offer in this area (quasiquotation and its many friends, for instance). The ability to output code that is pretty printed in a customized way is also a big plus (I care a great deal about the readability of the generated code). Also, the SQL flavor could be a pretty printing parameter - thus making it possible to write code that will run on many RDBMSs - but I'm not very hopeful about this, as differences between SQL dialects often go beyond syntax. Cons: I'm afraid of getting the SQL generating syntax wrong and making the data structures used for generation ugly. But I guess that can be fixed by iterating a little. :-) Thanks, -- Miron Brezuleanu --~--~-~--~~~---~--~~ 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: Scientific computing
On Thu, Oct 29, 2009 at 4:49 AM, Konrad Hinsen konrad.hin...@fastmail.netwrote: On 28 Oct 2009, at 22:21, Rock wrote: I honestly prefer your first case scenario. Seems much more efficient, less resource-consuming, and just straightforward. But I really would like to know what your preference is. If you had to choose, which way would you go? If I were to design an array interface for Clojure, it would consist of multimethods implemented for both an efficient array data structure for internal use and for nested vectors. The implementation for the latter would convert the nested vectors to the efficient structure and do all the necessary checks. It would be there for convenience and clarity in user code. Ideally I would then implement the same interface for Colt arrays and netCDF arrays as well, both for having an effcient structure for large data sets and for interoperability. And once we are at it, why not have another implementation for sparse arrays, using a suitable data structure? One issue with using multimethods is the resolution overhead. I don't think the JIT can optimize this to the extent it can optimize a normal polymorphic Java call. So you might want to use a Java interface for this instead, and Clojure's Java interop with macros to wrap a nice Clojury API around it. A second problem is boxing of primitives, and a third is noncontiguous storage. The Java for the nonsparse stuff should probably use and expose Java arrays of primitives. If you can live without runtime polymorphism, having only compile-time polymorphism, the polymorphism can move back to the Clojure side but live in a macro; then a sugar-coated API call directly translates at macroexpand time into manipulation of Java arrays in either Java calls or a Clojure function that uses loop/recur with primitives and is loaded with type hints for the array type used (likely double[]). --~--~-~--~~~---~--~~ 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: Scientific computing
I didn't address such issues because there is no point in discussing them before making the fundamental decision whether to use an abstract or an exposed data type for array data. That choice dictates the priorities for everything that follows. Yes, I agree. Suppose we're dealing with rank n objects. Do you think it would be an easy task to figure all that out dealing with nested vectors? If you can assume the array is well-formed, it is rather easy. Otherwise it isn't. Can you give an example in code? I really would like to see it. And by the way, How would you go about implementing in detail a check to see if a nested vector is actually an authentic multidimensional array or not? That's a rather simple recursive function. The only problem is its run- time cost. Please provide an example. In the meantime, I'll give it a shot myself. I honestly prefer your first case scenario. Seems much more efficient, less resource-consuming, and just straightforward. But I really would like to know what your preference is. If you had to choose, which way would you go? If I were to design an array interface for Clojure, it would consist of multimethods implemented for both an efficient array data structure for internal use and for nested vectors. The implementation for the latter would convert the nested vectors to the efficient structure and do all the necessary checks. It would be there for convenience and clarity in user code. Ideally I would then implement the same interface for Colt arrays and netCDF arrays as well, both for having an effcient structure for large data sets and for interoperability. And once we are at it, why not have another implementation for sparse arrays, using a suitable data structure? Yes, indeed I like your design. Makes sense. Unfortunately, a good design and implementation represents a lot of work. At the moment I am not sure if we have the critical mass of people interested in working on this to get the job done in a reasonable amount of time. Well. I'm willing to contribute. We can get this started. It won't hurt to give it a try. You never know ... I feel Clojure can and actually should become a language well-suited for scientific computation. It may not have all the prerequisites now, but, hey, this is Lisp, and it can be done, always! :) On 28 Oct 2009, at 23:07, harrison clarke wrote: maps could also be an option. you can use vectors of ints as keys. (and you can stick dimensions and such in there with keywords) i'm not sure how that compares to nested vectors for perforance. you have the overhead of the hash function, but you don't have any nesting. it's also pretty handy if you want to represent a sparse matrix. Maps could be a good choice for sparse arrays. For dense ones, they would represent an enormous waste of memory, and probably time as well. Well sparse arrays should always be treated more specifically I suppose (no use wasting all those resources!), One thing at a time :) Rock --~--~-~--~~~---~--~~ 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: Scriptjure, Parenscript - why not generate code in other languages
On Thu, Oct 29, 2009 at 8:15 AM, Miron Brezuleanu mbr...@gmail.com wrote: Hi, earlier today I was wondering about the best way to write some Transact-SQL code. I normally write code in C#, Python and lately Clojure. Even though TSQL is a decent procedural extension to SQL, it still feels very cumbersome to the languages I use daily. Having done some C# code generation lately (using ScriptTemplate), I was thinking about doing the same thing for SQL. At which point I remembered Scriptjure (and Parenscript) and thought about writing something similar for TSQL. Are you thinking of something like this? http://www.gitorious.org/clojureql/ --Chouser --~--~-~--~~~---~--~~ 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: Constructing Java Interop calls
On Thu, Oct 29, 2009 at 2:15 AM, Alex Osborne a...@meshy.org wrote: Using eval (which will also work for dynamically calling Clojure functions): (let [obj some string fname .substring] (eval (list (symbol fname) obj 2))) Thanks a lot. I was trying to avoid reflection (ie, looking for a clojure idiom), especially to get an understanding on what are clojure limitations. The eval form still shows some problems, if I do this preparation: (import javax.swing.JFileChooser) (def jfc (new JFileChooser)) And then do: user= (.setFileSelectionMode jfc 1) nil All good here, but, if I do the eval variation, user= (eval (list (symbol .setFileSelectionMode) jfc 1)) I get: #CompilerException java.lang.RuntimeException: Can't embed object in code, maybe print-dup not defined In theory it should work? What basic mistake am I doing here? BTW: user= (println (list (symbol .setFileSelectionMode) jfc 1)) (.setFileSelectionMode #JFileChooser javax.swing.JFileChooser[,0,0,0x0,invalid,layout=ja...] 1) So the list for the eval looks good... Many thanks, Tiago -- The hottest places in hell are reserved for those who, in times of moral crisis, maintain a neutrality. - Dante --~--~-~--~~~---~--~~ 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: Scientific computing
On 29.10.2009, at 14:01, Rock wrote: Suppose we're dealing with rank n objects. Do you think it would be an easy task to figure all that out dealing with nested vectors? If you can assume the array is well-formed, it is rather easy. Otherwise it isn't. Can you give an example in code? I really would like to see it. (defn rank [item] (if (vector? item) (inc (rank (nth item 0))) 0)) (rank 0) (rank [1 2 3]) (rank [[1 2] [3 4]]) (defn shape [item] (if (vector? item) (let [element (nth item 0) n (count item)] (cons n (shape element))) (list))) (shape 0) (shape [1 2 3]) (shape [[1 2] [3 4]]) And by the way, How would you go about implementing in detail a check to see if a nested vector is actually an authentic multidimensional array or not? That's a rather simple recursive function. The only problem is its run- time cost. Please provide an example. In the meantime, I'll give it a shot myself. (defn check-multiarray [item] (and (vector? item) (apply = (map shape item ; true (check-multiarray [1 2 3]) (check-multiarray [[1 2] [3 4]]) ; false (check-multiarray 1) (check-multiarray [[1 2] 3]) (check-multiarray [[1 2] [3]]) I feel Clojure can and actually should become a language well-suited for scientific computation. It may not have all the prerequisites now, but, hey, this is Lisp, and it can be done, always! :) I completely agree. I don't think Clojure will become a mainstream language for science any time soon, for that it is too exotic for a community that still sticks to Fortran. But it can find its niche, and perhaps not even a small one. Konrad. --~--~-~--~~~---~--~~ 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: Scientific computing
On 29.10.2009, at 13:48, John Harrop wrote: One issue with using multimethods is the resolution overhead. I don't think the JIT can optimize this to the extent it can optimize a normal polymorphic Java call. That's worth exploring - while keeping in mind that the JIT improves all the time. So you might want to use a Java interface for this instead, and Clojure's Java interop with macros to wrap a nice Clojury API around it. Maybe. For now I would consider this premature optimization. The big negative impact of using a Java interface is the impossibility to work with existing Java classes, such as Colt arrays. They would have to be wrapped in another object layer just for implementing the interface. A second problem is boxing of primitives, and a third is noncontiguous storage. The Java for the nonsparse stuff should probably use and expose Java arrays of primitives. I can see a role both for an implementation based on Clojure vectors and for one using Java arrays. With a multimethod interface, both can coexist. If you can live without runtime polymorphism, having only compile- time polymorphism, the polymorphism can move back to the Clojure side but live in a macro; Indeed. One could implement a polymorphic interface in one namespace and a compile-time polymorphic interface in another namespace, making it possible to switch easily between the two. What is nice about Clojure is that many of these implementation decisions can be changed later on without modifying the client-side API. Konrad. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~--~~~~--~~--~--~---
Re: Clojure in a big Java solution
On Oct 29, 4:50 pm, vanallan vanal...@gmail.com wrote: Ok thanks for the answer :) I have now began to implement the Java parts. The data that is going to be processed in Clojure is mapped to clojure structs, but I now have another question. How should I update the values in the structs? Since functions are going to run in parallel and a function may need the updated value from another function I though that I should put the struct members that is going to be updated in refs or maybe atoms. Is this a good way or how should I manage the updated values in structs? This, I think depends on your use case. If the parallel functions are in Clojure, then atoms and refs may help. If some functions are in Java and some in Clojure, and both sets of functions work in parallel to update commonly stored data then you should stick to concurrent Java collections (java.util.concurrent.*). But again, this depends on the use case. I think as long as the Java consumer class is ready to accept java.util.Map you can simply return a modified struct and it will be understood. But there is a pitfall to watch for -- the struct you return from Clojure will be immutable, so none of put(), remove() etc will work in Java then. When you are integrating Java with Clojure you should remember this aspect, and probably you will benefit tremendously if you code the Java part in a functional style, for example: 1. Go Immutable -- use the final keyword a lot (ensures at least immutable references) 2. Go Functional -- pass objects and anonymous functions (Strategy and Mediator patterns may help) 3. Don't presume data structures to be mutable HTH Regards, Shantanu --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~--~~~~--~~--~--~---
Re: Clojure in a big Java solution
2. Go Functional -- pass objects and anonymous functions (Strategy and Mediator patterns may help) I meant anonymous objects that implement some interface or extend a class (Template pattern), not anonymous functions really. :-) Regards, Shantanu --~--~-~--~~~---~--~~ 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: pointfree library
there are a few on git already: http://github.com/hclarke/pointfree-clojure/tree/master/src/ i'll add more soon. also, this could be worth looking at: http://www.haskell.org/arrows/ there will be some differences, but it's pretty much the same idea. On Oct 28, 9:09 pm, Paul Barry pauljbar...@gmail.com wrote: Would love to see some examples usages of these On Sun, Oct 25, 2009 at 4:16 PM, harrison clarke notall...@gmail.comwrote: so i was using haskell, and the pointfree stuff is fun, so naturally i had to implement some of it in clojure. this is what i have so far. library and examples within: http://github.com/hclarke/pointfree-clojure it has , , ***, +++, |||, and others they take functions as arguments and return functions for those that don't know: composes functions in reverse order. it basically pipes them together left to right maps functions over a single value (haskell's takes two functions, this takes any number) *** maps functions over a sequence (as above, this takes any number of functions) +++ takes a choice ([bool, x]), and applies f1 if f2 if false ([bool, (f x)]) ||| same as above, but just returns the (f x) part. drops the bool there's also: fst applies function to the first element. same as (*** f id id id...) snd applies function to the second element. same as (*** id f id id id...) ttt same as (+++ f id). same as haskell's left fff same as (+++ id f). same as haskell's right III takes [i x] and applies the ith function (starting from 0), returning [i (f x)] iii same as above, but drops the bool curry makes a function keep returning a function until you pass it enough arguments to evaluate (default is 2 args) see curry example on github for how it works at this point, names, and pretty much everything, are likely to change. thoughts, questions, suggestions, etc.? --~--~-~--~~~---~--~~ 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: Is it time to move the mailing list off of Google Groups?
+1 On Wed, Oct 28, 2009 at 4:47 PM, Michael Wood esiot...@gmail.com wrote: 2009/10/28 Kyle Schaffrick k...@raidi.us: Don't forget those of us who dislike web-forum software and prefer to interact with the group via email: I very seldom use the GG site itself. I find threaded email is a *very* good way of following discussions. I can have a I didn't know that moment delivered to my inbox every day, without having to visit a website and contend with the interface of yet-another-web-forum. +1 -- Michael Wood esiot...@gmail.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: Timing, JIT, Heisen-code
Hello all. Thanks everyone for the comments. This was the kind of info I was looking for. I'll play around with this some more when I get a chance. (Too many grants due / conferences in October.) cheers Matt On Oct 1, 10:08 am, Jonathan Smith jonathansmith...@gmail.com wrote: On Sep 30, 1:18 pm, Matt Brown mrbrow...@gmail.com wrote: Hi. Thanks all, for your comments. You need to use a bigger number than 1000 for these results to be meaningful. Out of curiousity, why is this? Does the JIT do something different after 1000 iterations? Or is the concern simply that the variance of the mean estimate is too high with 1000 vs. 10^6 iterations (due to OS background processes, etc.)? I originally reported ranges for average execution times (over about a dozen runs) to address this particular concern. Generally you get some error introduced by the GC and OS background processes. Doing it over 12 processes is similar to doing it like 10^5, but that still would run for less than a second total, and is still subject to interpretation. But anyway, doing it for different periods of time also lets you see that there is something else going on, and gets you more meaningful questions. Why do i do this a 10million times and get the same (close enough) result as doing it 1000 times?. FWIW, I've run both on my Toshiba dual core laptop with ubuntu, and they return approximately the same values. (and there is some JIT trickery going on, as I got: user= (myavgtime (+ 1 2 3) 1000 mytime1) (myavgtime (+ 1 2 3) 1000 mytime1) 0.002981158000306 user= (myavgtime (+ 1 2 3) 10 mytime1) (myavgtime (+ 1 2 3) 10 mytime1) 0.001742611283846 user= (myavgtime (+ 1 2 3) 1e8 mytime1) (myavgtime (+ 1 2 3) 1e8 mytime1) 0.0015456479935035251 Although the last one ran for quite a bit longer than ,0015) Thanks for posting this! One explanation for a decreasing mean execution time with an increasing number of iterations is this: The first iteration's execution time is relatively large because it's not JIT optimized (0.018 msec on my system). Increasing the number of iterations means you're averaging a larger number of small, JIT optimized individual execution times (reported as 0.000-0.001 msec on my system) into that initial larger value. The mean therefore becomes asymptotically smaller with larger numbers of iterations. Is there something else going on here as well though (eg: JIT stuff)? Most likely it is because the JIT compiler has completely eliminated the operation. You are measuring the time elapsed between system/nano calls. System/nano has some granularity, so it could be that doing a print forces it to always be worth at least 1 tick of system/nano, where-as not doing a print it can somehow call multiple calls to measure all within the same tick of system/nano? Meaning system/nano incrementing counter isn't necessarily synchronous with calls to measure? But doing the print forces it to do count on at least 1 seperate tick per measurement. Using a million iterations, I got: (myavgtime (+ 1 2 3) 1e6 mytime1) - 0.00027 - 0.00029 msec (over a dozen repeats) (myavgtime (+ 1 2 3) 1e6 mytime2) - 0.00068 msec (single run, printing 10^6 lines takes a long time, I was too impatient for repeats) So, using mytime1 is still just over 2x faster than mytime2 with 10^6 iterations. cheers Matt Perhaps you could retry with some other side-effecting function, like making a java array of 1 boolean and flipping the boolean back and forth? (and also something with a longer timeframe) In cases of measurement, I think it makes more sense to time the loop itself than to time the individual calls and sum them. Looping overhead is small, and with a non-trivial operation, it should be outweighed by whatever else is going on. On Sep 29, 12:08 pm, Matt mrbrow...@gmail.com wrote: Hi. I'm getting a three-fold difference in timing results when I add a seemingly trivial println to observe what's going on. Consider: (defmacro mytime1 Returns execution time of expr in millisecs [expr] `(let [time0# (. System nanoTime) exprval# ~expr time1# (/ (double (- (. System nanoTime) time0#)) 100.0)] time1#)) (defmacro mytime2 Prints out execution time of expr in millisecs and returns it [expr] `(let [time0# (. System nanoTime) exprval# ~expr time1# (/ (double (- (. System nanoTime) time0#)) 100.0)] (println elapsed time (msec): time1#) time1#)) Timing macros mytime1 and mytime2 differ only in that mytime2 has the println expression in the second last line. The println in mytime2 comes after time1# is assigned, so the println expression's execution time shouldn't be counted. I confirmed this assumption by testing. (mytime1 (+ 1 2 3)) and (mytime2 (+ 1
Re: pointfree library
I'm a huge fan of point free code. Some of you functions already exist in Clojure under different names, and I have a few questions. is the same as (reverse (comp x)) right? is called juxt *** - I believe this (map (juxt f-coll) coll) curry is called partial Still, good to see the comparison. On Oct 29, 10:20 am, harrison clarke notall...@gmail.com wrote: there are a few on git already:http://github.com/hclarke/pointfree-clojure/tree/master/src/ i'll add more soon. also, this could be worth looking at:http://www.haskell.org/arrows/ there will be some differences, but it's pretty much the same idea. On Oct 28, 9:09 pm, Paul Barry pauljbar...@gmail.com wrote: Would love to see some examples usages of these On Sun, Oct 25, 2009 at 4:16 PM, harrison clarke notall...@gmail.comwrote: so i was using haskell, and the pointfree stuff is fun, so naturally i had to implement some of it in clojure. this is what i have so far. library and examples within: http://github.com/hclarke/pointfree-clojure it has , , ***, +++, |||, and others they take functions as arguments and return functions for those that don't know: composes functions in reverse order. it basically pipes them together left to right maps functions over a single value (haskell's takes two functions, this takes any number) *** maps functions over a sequence (as above, this takes any number of functions) +++ takes a choice ([bool, x]), and applies f1 if f2 if false ([bool, (f x)]) ||| same as above, but just returns the (f x) part. drops the bool there's also: fst applies function to the first element. same as (*** f id id id...) snd applies function to the second element. same as (*** id f id id id...) ttt same as (+++ f id). same as haskell's left fff same as (+++ id f). same as haskell's right III takes [i x] and applies the ith function (starting from 0), returning [i (f x)] iii same as above, but drops the bool curry makes a function keep returning a function until you pass it enough arguments to evaluate (default is 2 args) see curry example on github for how it works at this point, names, and pretty much everything, are likely to change. thoughts, questions, suggestions, etc.? --~--~-~--~~~---~--~~ 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: Scriptjure, Parenscript - why not generate code in other languages
Hello, On Thu, Oct 29, 2009 at 3:06 PM, Chouser chou...@gmail.com wrote: earlier today I was wondering about the best way to write some Transact-SQL code. I normally write code in C#, Python and lately Clojure. Even though TSQL is a decent procedural extension to SQL, it still feels very cumbersome to the languages I use daily. Having done some C# code generation lately (using ScriptTemplate), I was thinking about doing the same thing for SQL. At which point I remembered Scriptjure (and Parenscript) and thought about writing something similar for TSQL. Are you thinking of something like this? http://www.gitorious.org/clojureql/ Thanks! clojureql seems to be very close to what I need. -- Miron Brezuleanu --~--~-~--~~~---~--~~ 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: pointfree library
it does look like is pretty much the same as juxt. partial isn't the same as curry, though. (curry uses thunk, which is the same as partial, but can take a function and no args) curry waits for a specific number of args before it evals. so if you keep evaluating a curried fn with 0 args, you'll keep getting a curried fn back. (default is 2 args, but you can specify any number) On Oct 29, 12:42 pm, Sean Devlin francoisdev...@gmail.com wrote: I'm a huge fan of point free code. Some of you functions already exist in Clojure under different names, and I have a few questions. is the same as (reverse (comp x)) right? is called juxt *** - I believe this (map (juxt f-coll) coll) curry is called partial Still, good to see the comparison. On Oct 29, 10:20 am, harrison clarke notall...@gmail.com wrote: there are a few on git already:http://github.com/hclarke/pointfree-clojure/tree/master/src/ i'll add more soon. also, this could be worth looking at:http://www.haskell.org/arrows/ there will be some differences, but it's pretty much the same idea. On Oct 28, 9:09 pm, Paul Barry pauljbar...@gmail.com wrote: Would love to see some examples usages of these On Sun, Oct 25, 2009 at 4:16 PM, harrison clarke notall...@gmail.comwrote: so i was using haskell, and the pointfree stuff is fun, so naturally i had to implement some of it in clojure. this is what i have so far. library and examples within: http://github.com/hclarke/pointfree-clojure it has , , ***, +++, |||, and others they take functions as arguments and return functions for those that don't know: composes functions in reverse order. it basically pipes them together left to right maps functions over a single value (haskell's takes two functions, this takes any number) *** maps functions over a sequence (as above, this takes any number of functions) +++ takes a choice ([bool, x]), and applies f1 if f2 if false ([bool, (f x)]) ||| same as above, but just returns the (f x) part. drops the bool there's also: fst applies function to the first element. same as (*** f id id id...) snd applies function to the second element. same as (*** id f id id id...) ttt same as (+++ f id). same as haskell's left fff same as (+++ id f). same as haskell's right III takes [i x] and applies the ith function (starting from 0), returning [i (f x)] iii same as above, but drops the bool curry makes a function keep returning a function until you pass it enough arguments to evaluate (default is 2 args) see curry example on github for how it works at this point, names, and pretty much everything, are likely to change. thoughts, questions, suggestions, etc.? --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
Error messages
Often , i get error messages like #CompilerException java.lang.IllegalStateException: Var swank.core.connection/*current-connection* is unbound. (NO_SOURCE_FILE: 358) My question is how do i know what the source file name is? Do i somehow need to include it when compiling or what? If i know where the error is, life would be much easier! --~--~-~--~~~---~--~~ 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: Error messages
Where did you get this from? Were you using SLIME at the time? On Oct 29, 12:22 pm, Gorsal s...@tewebs.com wrote: Often , i get error messages like #CompilerException java.lang.IllegalStateException: Var swank.core.connection/*current-connection* is unbound. (NO_SOURCE_FILE: 358) My question is how do i know what the source file name is? Do i somehow need to include it when compiling or what? If i know where the error is, life would be much easier! --~--~-~--~~~---~--~~ 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: Error messages
Sorry. I was just compiling everything and changing some code so it broke. Where it actually came from is probably irrelevant, i have gotten the phrase 'NO_SOURCE_FILE' when compiling before. --~--~-~--~~~---~--~~ 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: Error messages
Oh, my actual question was to ask why the general NO_SOURCE_FILE would appear and how to fix it, the specific error message was just an example. --~--~-~--~~~---~--~~ 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: Error messages
In my experience, the NO_SOURCE_FILE shows up when I make a mistake at the REPL/SLIME. When I have a precompiled .JAR, then I get a reference to a specific file w/ a mistake in it. That's why I was asking about what environment you used. On Oct 29, 1:30 pm, Gorsal s...@tewebs.com wrote: Oh, my actual question was to ask why the general NO_SOURCE_FILE would appear and how to fix it, the specific error message was just an example. --~--~-~--~~~---~--~~ 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: Error messages
My environment is enclojure on netbeans. Ive compiled all of the code for swank-clojure. However, when i call a function which produces a certain error (in a new case, attempting to call some invalid java method on a java object) i get the no source file thing. So im guessing that somehow i have to tell clojure where my source files are? Also, (.printStackTrace *e) produces nil. --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
Newcomer's question about Clojure's compatibility with common lisp
Hello, First let me congratulate the clojure team on this wonderful initiative: porting lisp to the jvm. Next is my question: can I run common lisp programs on the jvm using clojure? I was thinking specifically to Maxima - (the formal calculus program)? And finally another question: are there any ubuntu packages for clojure available at this time? Thanks in advance, Julien. --~--~-~--~~~---~--~~ 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: Scriptjure, Parenscript - why not generate code in other languages
Hi, On Oct 29, 1:15 pm, Miron Brezuleanu mbr...@gmail.com wrote: The pros I see are the ability to construct the data structure using all the tools Clojure/Lisp offer in this area (quasiquotation and its many friends, for instance). The ability to output code that is pretty printed in a customized way is also a big plus (I care a great deal about the readability of the generated code). Also, the SQL flavor could be a pretty printing parameter - thus making it possible to write code that will run on many RDBMSs - but I'm not very hopeful about this, as differences between SQL dialects often go beyond syntax. Cons: I'm afraid of getting the SQL generating syntax wrong and making the data structures used for generation ugly. But I guess that can be fixed by iterating a little. :-) ClojureQL[1] does that to some extent. Currently MySQL and Derby are supported as backends, Postgres to some extent (so it has issues, IIRC). The generation part consists of multimethods compiling the defined queries into JDBC PreparedStatements. Up to now we managed to hide the backend as much as possible, but the feature set of ClojureQL is still limited. So my suspicion is that the backend will leak through eventually... But we'll see. Nice effect: ClojureQL allows FULL JOINs with a Derby backend. Derby does not support FULL JOIN. Sincerely Meikel [1]: http://gitorious.org/clojureql --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~--~~~~--~~--~--~---
Re: Clojure in a big Java solution
All the parallel work will be done in Clojure, so I think I will go with the refs and atom path. When the processing in Clojure is done the data is passed as XML to another system so Java doesn't need to change it anymore, so the immutability when it's done is not a problem. Thank you very much for your answer, it really helped :) On Oct 29, 2:43 pm, Shantanu Kumar kumar.shant...@gmail.com wrote: On Oct 29, 4:50 pm, vanallan vanal...@gmail.com wrote: Ok thanks for the answer :) I have now began to implement theJavaparts. The data that is going to be processed inClojureis mapped toclojurestructs, but I now have another question. How should I update the values in the structs? Since functions are going to run in parallel and a function may need the updated value from another function I though that I should put the struct members that is going to be updated in refs or maybe atoms. Is this a good way or how should I manage the updated values in structs? This, I think depends on your use case. If the parallel functions are inClojure, then atoms and refs may help. If some functions are inJavaand some inClojure, and both sets of functions work in parallel to update commonly stored data then you should stick to concurrentJavacollections (java.util.concurrent.*). But again, this depends on the use case. I think as long as theJavaconsumer class is ready to acceptjava.util.Map you can simply return a modified struct and it will be understood. But there is a pitfall to watch for -- the struct you return fromClojurewill be immutable, so none of put(), remove() etc will work inJavathen. When you are integratingJavawithClojureyou should remember this aspect, and probably you will benefit tremendously if you code theJavapart in a functional style, for example: 1. Go Immutable -- use the final keyword a lot (ensures at least immutable references) 2. Go Functional -- pass objects and anonymous functions (Strategy and Mediator patterns may help) 3. Don't presume data structures to be mutable HTH Regards, Shantanu --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
Observations from a real-world Clojure project
First, thank you Rich Co for doing Clojure. We've been using Clojure for a real-world project, and I thought I'd share some observations. The project does some large-scale (but not really huge) data analysis. Example: ~10M records are processed and transformed, various computations occur, and ~100K records are spit out. Lots of statistics. One type of run takes 12 hours on an 8GB, 4-core Linux box. A few thousand lines of our Clojure code in total. My background: I'm an old (?) Lisp hacker. I've used Symbolics, ACL, CMUCL, schemes (including JScheme and SISC). Also Java since its early days. And my share of C, C++, SQL, Perl, etc. So here are some observations. None are news flashes. 1. Clojure works. We were obviously cautious about using a relatively new system for real work. We tried Clojure, and then we tried some more. Everything* just worked. We took a snapshot at 1.1.0, and we didn't update it. [* The JVM does SEGV on us occasionally. Internal error, which we have not diagnosed. Probably a GC issue. Java 1.6.0_14 with HotSpot 14.0-b16 64-bit server. But this problem is another topic.] 2. Clojure-the-language is a good fit for real work. The language has a distinct DWIM feel, which I like. Destructuring everywhere, auto- gensym-ing, various syntactic sugar, and the advanced features (e.g., concurrency primitives with STM, tries) are all convenient, effective, and useful. Clojure is practical. 3. We dropped into Java once to implement an LRU cache to back custom memoization. We presumably could have implemented the cache in Clojure, but Java seemed simpler. Probably mostly due to our inexperience with Clojure. Clojure's Java interop is of course excellent -- as claimed and widely reported. 4. Reminder: concurrent work on distinct datastructures uses memory concurrently! Obvious and obviously not specific to Clojure. But Clojure makes it so easy to do things in parallel that it's easy to forget the implications. We found ourselves having to do some judicious doall's and such to avoid running out of memory in a subsequent -- so to speak -- stage. (Imagine a parallel aggregation of a lot of data that results in a small object, which is then subsequently used with different big data. Might not be able to work on the former and latter at the same time.) So watch out when you work on distinct data in stages in parallel on that 100-core Tilera board. Aside: We might like the option of selective non-laziness, but we're not sure. That's yet another topic. 5. The functionality of the docs hasn't kept up with Clojure. We often resorted to text searches of the various sources. Need links and see-also's. Clojure has grown/matured so much that it needs a doc system of some sort. 6. Debugging facilities also have not kept up with the state of Clojure. We use Slime and JDB and some contributed tools, but the result isn't that convenient. I miss the good Lisp debuggers, but I'm old-fashioned I guess. We need to re-survey what's available for tracing, logging, restarts, etc. A state-of-the-art tutorial would be great. 7. We use Incanter (http://incanter.org/), which worked well for some of the statistics we need. BTW, for different work, we still use Mathematica, but we haven't yet needed the slick-looking Clojuratica (http://clojuratica.weebly.com/). We probably will, and I'm eager to use it. For us, Clojure is becoming the application-level, all- purpose glue. We can't throw away Mathematica or Matlab or R, and we don't need to. That's it for now. We'll look for ways we can contribute. Thanks again for the excellent system. --Jamie --~--~-~--~~~---~--~~ 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: Constructing Java Interop calls
Hi, On Oct 29, 2:07 pm, Tiago Antão tiagoan...@gmail.com wrote: The eval form still shows some problems, if I do this preparation: (import javax.swing.JFileChooser) (def jfc (new JFileChooser)) And then do: user= (.setFileSelectionMode jfc 1) nil All good here, but, if I do the eval variation, user= (eval (list (symbol .setFileSelectionMode) jfc 1)) Another example which shows that eval is not worth the trouble. It is better to use reflection. You cannot embed the JFileChooser as a object into the code. You have to construct it in your eval. (eval ` (let [chooser# (JFileChooser.)] (~(symbol .setFileSelectionMode) chooser# 1) chosser#)). Hopes this helps. 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: Constructing Java Interop calls
user= ((eval `(fn [x#] (~(symbol .setFileSelectionMode) x# 1))) jfc) nil user= On Thu, Oct 29, 2009 at 6:38 AM, Meikel Brandmeyer m...@kotka.de wrote: Hi, On Oct 29, 2:07 pm, Tiago Antão tiagoan...@gmail.com wrote: The eval form still shows some problems, if I do this preparation: (import javax.swing.JFileChooser) (def jfc (new JFileChooser)) And then do: user= (.setFileSelectionMode jfc 1) nil All good here, but, if I do the eval variation, user= (eval (list (symbol .setFileSelectionMode) jfc 1)) Another example which shows that eval is not worth the trouble. It is better to use reflection. You cannot embed the JFileChooser as a object into the code. You have to construct it in your eval. (eval ` (let [chooser# (JFileChooser.)] (~(symbol .setFileSelectionMode) chooser# 1) chosser#)). Hopes this helps. Sincerely Meikel -- And what is good, Phaedrus, And what is not good— Need we ask anyone to tell us these things? --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
Generalizing - -
Here's a macro that generalizes the two 'threading' macros - and -. It works by using the idea of 'nesting marker' (from Oz) to specify where the result of the previous form should be nested in the subsequent form. (defmacro -$ Threads the expr through the forms. Inserts x into the first form at the position marked by the $ symbol. If the second form is not a list then it behaves as -. If there are more forms, inserts the first form into the second form at the position marked by the $ symbol, etc. ([x form] (if (seq? form) (let [split (split-with (partial (complement =) '$) form)] `(~@(first split) ~x ~@(rest (second split (list form x))) ([x form more] `(-$ (-$ ~x ~form) ~...@more))) If this is any use to anyone (esp. anyone who has a CA) then consider it public domain. Any improvements appreciated! --~--~-~--~~~---~--~~ 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: Embedding Clojure in NetKernel
Hi Roman, sure. Tom sent me a link to this thread: http://groups.google.com/group/clojure/browse_thread/thread/d98cedb860f16a34/ and also he sent me a tgz of his NetKernel module. I believe he has licensed it to be freely available: /** * CloNK4 Project : Clojure for NetKernel 4. * Copyright (C) 2008 by Tohono Consulting LLC. All rights reserverd. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. */ However I'll need him to confirm that before distributing it. Tom did a great job of getting it working and solving a lot of the integration issues. But things seem to have changed a bit in both the NetKernel world and Clojure world since this code was written and it doesn't work now. I'm working through it try to get it on its feet again. Though my knowledge of Clojure is very limited. I'll post again on this group when I get something working or need to ask for help. Cheers, Tony On Oct 29, 9:58 am, Roman Roelofsen roman.roelof...@googlemail.com wrote: Do you mind sharing the links? I am interested in it as well. Thanks! Roman 2009/10/28 Tony Butterfield t...@1060.org: Tom Hicks has just pointed me to an old thread which answers questions about namespaces and isolation. Let me read and absorb all that work first - I suspect it answers a lot of my questions. Cheers, Tony On Oct 28, 11:43 am, Tony Butterfield t...@1060.org wrote: Hi Everybody this is my first post to this group so please tell me If I'm posting in the wrong place. I've been looking at integrating Clojure into NetKernel as language runtime library but I'm struggling a bit for a lack of examples. There are two things I'm trying to achieve: 1) start and stop the Clojure runtime on demand. I need to do this so that new versions can be deployed whilst the server is live. Looking at the latest version (1.0.0) I see that I no longer need to call RT.init() and that startup is done statically. That's fine but is there a way to cleanly shutdown. I.e. stop threads, and enable a full garbage collection of the Clojure libraries? 2) is there a way to ensure isolation of functionality in one runtime? I can see how I can use namespaces to avoid naming collisions but is it possible to enforce tighter security across namespaces or is there another technique? I'm quite new to closure so sorry if that is a stupid question - the trouble is I want to get it running inside NetKernel as good environment to explore the language - horse before the cart! When Clojure scripts execute inside NetKernel environment it is important that they act like pure functions with no side-effects on others. Thanks in advance for you advice, Tony --~--~-~--~~~---~--~~ 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: ANN: Clojure live-repl
* Is it OK if live-repl uses one version of Clojure and the attached process uses another? It should be fine. I check to see if Clojure is already on the process's classpath. If it isn't a Clojure process, I use the bundled copy of Clojure; if Clojure is already loaded then I just use that and don't use the bundled copy to avoid the risk of any conflicts. A side effect of this is that if the process doesn't have Clojure loaded, and you connect multiple liverepls, then they all get isolated copies of Clojure. It would probably be better if they could have a shared instance of Clojure, but I'm not sure if that is possible... I think it would be great if JLine is integrated in live-repl. Could be good, but it is also nice to be able to do C-M-x run-lisp, and then use liverepl to connect Emacs's inferior-lisp mode to a running process, and I don't know whether jline might interfere with that. * Why not use maven and clojure-maven-plugin? I don't know anything about maven. You could always make a symlink of clojure.jar from your preferred Clojure install location? I do plan to add a feature so that it loads all jars from a lib directory, that way you'll be able to use, eg, clojure-contrib, even if it isn't loaded by the process. -- Dave --~--~-~--~~~---~--~~ 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: Java 7, nio, and createFile
Works beautifully. Thank you sir.
On Oct 28, 10:40 pm, Alex Osborne a...@meshy.org wrote:
youngblood.carl wrote:
When I try and call createFile from clojure:
(.createFile path)
I get an exception that there is no field named createFile.
If I remember correctly variable argument Java methods, which is what
that ... syntax means:
abstract Path createFile(FileAttribute?... attrs) {}
are actually just syntactic sugar for an array argument:
abstract Path createFile(FileAttribute?[] attrs) {}
so try:
(.createFile path (make-array FileAttribute 0))
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Re: Newcomer's question about Clojure's compatibility with common lisp
You can't use Clojure to run Common Lisp programs on the JVM. Clojure is it's own Lisp, and has nothing to do with Common Lisp. There are some implementations of Common Lisp on the JVM, the most popular of which I believe is ABCL. I believe there are some experimental Ubuntu packages available, but I would highly recommend that you just pull it from the github repository. On Oct 29, 7:09 am, bal...@gmail.com bal...@gmail.com wrote: Hello, First let me congratulate the clojure team on this wonderful initiative: porting lisp to the jvm. Next is my question: can I run common lisp programs on the jvm using clojure? I was thinking specifically to Maxima - (the formal calculus program)? And finally another question: are there any ubuntu packages for clojure available at this time? Thanks in advance, Julien. --~--~-~--~~~---~--~~ 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: Newcomer's question about Clojure's compatibility with common lisp
On Thu, Oct 29, 2009 at 4:34 PM, Rayne disciplera...@gmail.com wrote: but I would highly recommend that you just pull it from the github repository. Especially if you're going to use clojure-contrib ...or is there some release of contrib synch'd to clojure releases that I missed somewhere? --~--~-~--~~~---~--~~ 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: Newcomer's question about Clojure's compatibility with common lisp
Daniel Simms wrote: On Thu, Oct 29, 2009 at 4:34 PM, Rayne disciplera...@gmail.com wrote: but I would highly recommend that you just pull it from the github repository. Especially if you're going to use clojure-contrib ...or is there some release of contrib synch'd to clojure releases that I missed somewhere? There's a 1.0 compatible branch on github. You get it with: git clone git://github.com/richhickey/clojure-contrib.git cd clojure-contrib git checkout origin/clojure-1.0-compatible Or download a tarball from: http://github.com/richhickey/clojure-contrib/archives/clojure-1.0-compatible --~--~-~--~~~---~--~~ 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: ANN: Clojure live-repl
I do plan to add a feature so that it loads all jars from a lib directory This is a nice feature! I don't know anything about maven I'm brand new to maven, but let me introduce some advantages if maven were used. Take http://github.com/ngocdaothanh/telchat-clojure as an example: * Run mvn compile and all needed .jar files are automatically downloaded, then .java files are compiled * Run mvn clojure:run to start, clojure-maven-plugin will automatically load all dependency .jar files as specified in pom.xml (this file is very short, have a look at it) * To load all jars from a lib directory, you don't have to manually download and copy .jar files, you only have add a dependency to pom.xml. The manually download .jar files job may become very hard and time consuming if library A needs library B, C, D etc., you have to go everywhere to collect all .jar files yourselve. To add a dependency, in most cases all you have to do is go to mvnrepository.com and search. CPAN brings convention to Perl, RubyGem brings convention to Ruby. This kind of convention can make Clojure move forward faster. Maven can do it, as long as we community make a consensus to give it a chance. The point of using Clojure instead of other Lisps is that you can use too many existing Java things right away. Then why not use Maven right away? On Fri, Oct 30, 2009 at 7:37 AM, David Powell d...@djpowell.net wrote: * Is it OK if live-repl uses one version of Clojure and the attached process uses another? It should be fine. I check to see if Clojure is already on the process's classpath. If it isn't a Clojure process, I use the bundled copy of Clojure; if Clojure is already loaded then I just use that and don't use the bundled copy to avoid the risk of any conflicts. A side effect of this is that if the process doesn't have Clojure loaded, and you connect multiple liverepls, then they all get isolated copies of Clojure. It would probably be better if they could have a shared instance of Clojure, but I'm not sure if that is possible... I think it would be great if JLine is integrated in live-repl. Could be good, but it is also nice to be able to do C-M-x run-lisp, and then use liverepl to connect Emacs's inferior-lisp mode to a running process, and I don't know whether jline might interfere with that. * Why not use maven and clojure-maven-plugin? I don't know anything about maven. You could always make a symlink of clojure.jar from your preferred Clojure install location? I do plan to add a feature so that it loads all jars from a lib directory, that way you'll be able to use, eg, clojure-contrib, even if it isn't loaded by the process. -- Dave --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
