Re: Introduction to Monads in Clojure tech talk
Thank you! Nice step by step intro. Regards, alux On 9 Apr., 06:04, Mike T. Miller jini...@gmail.com wrote: Adam Smyczek's Introduction to Monads video is now available. http://www.youtube.com/user/LinkedInTechTalks?feature=mhw5#p/u/0/ObR3... I'll work on getting an HD version up Friday. -mike -- 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 To unsubscribe, reply using remove me as the subject.
Introduction to Monads in Clojure tech talk
Adam Smyczek's Introduction to Monads video is now available. http://www.youtube.com/user/LinkedInTechTalks?feature=mhw5#p/u/0/ObR3qi4Guys I'll work on getting an HD version up Friday. -mike -- 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
symbol-macrolet (was: Monads in Clojure)
On 25.11.2008, at 15:06, Konrad Hinsen wrote: I just saw a reference to symbol-macrolet with a description. My function replace-syms is indeed very similar, the difference being that it takes a map for defining the substitutions to be done, instead of a let-like sequence. The difference is not just in syntax though, as expressions in symbol-macrolet can refer to earlier bindings (they aren't really bindings) whereas my replace-syms doesn't check for substitutions to be made inside other substitutions. But it would be fairly easy to implement symbol- macrolet on top of my replace-syms. After having read more on macrolet and symbol-macrolet, I no longer agree with my earlier self ;-) symbol-macrolet does not do a simple substitution, it creates a binding-like environment from which replacements are done repeatedly as other macros are expanded. I haven't yet found a complete description of how macros and symbol-macrolet work together. A macro can expand into code that contains a symbol defined in symbol- macrolet, and the expansion of such a symbol can produce code containing macros. I'd expect everything to be expanded repeatedly until the form no longer changes, but I haven't see this being stated explicitly anywhere. In any case, implementing macrolet and symbol-macrolet is probably not a trivial project. I see basically two approaches: 1) Full repeated expansion of the form, which is then handed to the compiler. 2) Implementation as an extension to the compiler's macro handling scheme. When I started working on my monad implementation, I was in fact looking for something much like macrolet, and if I had pursued that approach I would have wanted symbol-macrolet just a bit later. Both would be nice to have. 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 To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~--~~~~--~~--~--~---
Re: Monads in Clojure
On Nov 21, 2008, at 17:10, Chouser wrote: This is pretty code. Did you just implement symbol-macro-let? Very nice. I just saw a reference to symbol-macrolet with a description. My function replace-syms is indeed very similar, the difference being that it takes a map for defining the substitutions to be done, instead of a let-like sequence. The difference is not just in syntax though, as expressions in symbol-macrolet can refer to earlier bindings (they aren't really bindings) whereas my replace-syms doesn't check for substitutions to be made inside other substitutions. But it would be fairly easy to implement symbol- macrolet on top of my replace-syms. Would that be something of interest to the Clojure community? 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 To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~--~~~~--~~--~--~---
Re: Monads in Clojure
On Nov 25, 2008, at 9:06 AM, Konrad Hinsen wrote: But it would be fairly easy to implement symbol- macrolet on top of my replace-syms. Would that be something of interest to the Clojure community? I have no experience with it myself, but I've seen it discussed as something that would be a welcome addition to Clojure. It's on Rich's to-do list as the second item listed under Long-term: http://richhickey.backpackit.com/pub/1597914 --Steve --~--~-~--~~~---~--~~ 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 To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~--~~~~--~~--~--~---
Re: Monads in Clojure
On 21.11.2008, at 20:10, Adam Jones wrote: The file contains the macro definitions, the definitions of three popular monads (maybe, list, state), and some illustrations of their use. Comments are welcome! Since they support mzero and mplus, aren't these equivalent to Haskell's MonadPlus? (i.e. they're a little more than *just* monads) You can define :plus and :zero if they are appropriate for a monad. If they are defined, you can use them. None of the predefined monad machinery will use them at the moment, but I plan to implement conditions, which work only if :zero is defined. In Haskell there are two different types of monads because of the type system, but the Clojure implementation doesn't use the type system at all, so :plus and :zero are simply used by convention. I've been kicking around the idea of re-implementing Haskell typeclasses on top of multimethods. Now that I think more about it, this probably wouldn't be much work. You need to find a way to store the type information with the data. That is easy if you limit yourself to a specific data structure, say a map with a key reserved for type information. But if you want to be able to use typeclasses for general Clojure data (e.g. make sequences an instance of Monad), I don't see a simple way to do it. 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 To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~--~~~~--~~--~--~---
Re: Monads in Clojure
On Nov 23, 1:15 pm, Konrad Hinsen [EMAIL PROTECTED] wrote: On 21.11.2008, at 20:10, Adam Jones wrote: The file contains the macro definitions, the definitions of three popular monads (maybe, list, state), and some illustrations of their use. Comments are welcome! Since they support mzero and mplus, aren't these equivalent to Haskell's MonadPlus? (i.e. they're a little more than *just* monads) You can define :plus and :zero if they are appropriate for a monad. If they are defined, you can use them. None of the predefined monad machinery will use them at the moment, but I plan to implement conditions, which work only if :zero is defined. In Haskell there are two different types of monads because of the type system, but the Clojure implementation doesn't use the type system at all, so :plus and :zero are simply used by convention. I've been kicking around the idea of re-implementing Haskell typeclasses on top of multimethods. Now that I think more about it, this probably wouldn't be much work. You need to find a way to store the type information with the data. That is easy if you limit yourself to a specific data structure, say a map with a key reserved for type information. But if you want to be able to use typeclasses for general Clojure data (e.g. make sequences an instance of Monad), I don't see a simple way to do it. That's the problem I've been thinking on. I'm looking for a decently sane way to build on the multimethod dispatch system here instead of explicitly relying on types. The concept probably doesn't work very well without a guaranteed unique method of identifying an object, like a data type. -Adam 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 To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~--~~~~--~~--~--~---
Monads in Clojure
As a first non-trivial exercice, I wrote an implementation of monads in Clojure. I just uploaded it to the Group: http://clojure.googlegroups.com/web/monads.clj The file contains the macro definitions, the definitions of three popular monads (maybe, list, state), and some illustrations of their use. Comments are welcome! One thing I was wondering about: if I want to turn this into a library module, where could I place it in Java's namespace hierarchy? I don't have my own domain (and don't need one), and even though I could have it hosted somewhere (such as SourceForge), it doesn't look like a good idea to have the package name depend on a hosting site that might not be forever. How do others approach this problem? 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 To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~--~~~~--~~--~--~---
Re: Monads in Clojure
On Nov 21, 2008, at 15:01, walterc wrote: how about clojure-contrib? Actually, I have no idea of how clojure-contrib works. Is this a repository for all kinds of Clojure add-ons? Or stuff selected by Rich for a specific reason? 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 To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~--~~~~--~~--~--~---
Re: Monads in Clojure
On 21.11.2008, at 17:10, Chouser wrote: On Fri, Nov 21, 2008 at 6:14 AM, Konrad Hinsen [EMAIL PROTECTED] wrote: As a first non-trivial exercice, I wrote an implementation of monads in Clojure. I just uploaded it to the Group: http://clojure.googlegroups.com/web/monads.clj This is pretty code. Did you just implement symbol-macro-let? Very nice. Thanks! I don't know what symbol-macrolet is/does, so I can't comment on that. It's probably some Common Lisp thing, right? I noticed that you have a private function (monad-expr) used by a macro, and was about to comment that that doesn't work -- but your function is used by the macro, not the *expansion* of the macro, so it should work just fine. I'll have to keep that in mind. Yes, it is used only at expansion time. (zero? n) is an idiom for (= 0 n) Good to know! 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 To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~--~~~~--~~--~--~---
Re: Monads in Clojure
Stuart Sierra writes: Rich gives out commit permission on clojure-contrib to people who are interested, but he doesn't dictate what goes in. You have to sign the Clojure Contributor agreement, which basically says that if the Clojure license changes at some point, you allow your contribution to be released under the same license (still open-source, of course). This paper http://www.rosenlaw.com/OSL3.0-explained.pdf suggests an alternative to contributor agreements that might be worth considering. Here is the relevant section: This is also a function that can be performed by the Academic Free License. AFL 3.0 is identical to OSL 3.0 except that licensees are now free to distribute or communicate copies of the Original Work and Derivative Works to the public, under any license of your choice that does not contradict the terms and conditions, including Licensor's reserved rights and remedies, in this Academic Free License. That makes AFL 3.0 a suitable contributor license to other open source projects, especially (but not only) those projects distributing software under OSL 3.0. The project is then free to revise its outgoing license in accordance with its bylaws and charter as the times dictate. Instead of a contributor agreement, then, I often recommend that contributors offer their contribution to a project by placing the following notice adjacent to their copyright notice: Licensed to Project XYZ under the Academic Free License (AFL 3.0). --~--~-~--~~~---~--~~ 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 To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~--~~~~--~~--~--~---
