12 ms·

Lisp in Small Pieces of Clojure, part 3

183 points by ghosthamlet 8y ago

laxentasken 8y ago
This is part three. Part one: http://gmorpheme.net/lisp-in-small-pieces-of-clojure-part-1.html http://gmorpheme.net/lisp-in-small-pieces-of-clojure-part-1.... Part two: http://gmorpheme.net/lisp-in-small-pieces-of-clojure-part-2.html http://gmorpheme.net/lisp-in-small-pieces-of-clojure-part-2....
- benjaminsuch 8y ago
  That's whats mentioned right at the start of the article? This continues a translation of various parts of Lisp in Small Pieces into Clojure. For earlier chapters, see: Lisp in Small Pieces of Clojure - part 1. Lisp in Small Pieces of Clojure - part 2.
agumonkey 8y ago
I applaud joyfully.
cup-of-tea 8y ago
Oh this looks great. I loved L.I.S.P. I did plan to dust off my French and try the second edition. But I'm sure I'll enjoy this just as much.
- nextos 8y ago
  A testament about the quality of Lisp is the breadth and depth of its literature: SICP, PAIP, On Lisp, Lisp in Small Pieces, CLtL... The only great book I'd like to see written in Lisp is CTM.
  - cylinder714 8y ago
    "CTM"?
    - sigjuice 8y ago
      https://mitpress.mit.edu/books/concepts-techniques-and-models-computer-programming https://mitpress.mit.edu/books/concepts-techniques-and-model...
    - deleted 8y ago
      [deleted]
  - Lozzer 8y ago
    I'd add Let over Lambda (LOL) to that list.
- aidenn0 8y ago
  For those who are not francophones, there is also an English translation.
globuous 8y ago
Slightly unrelated, but to those who have never tried Lisp because of the parenthesis (like me until recently), here's my take: I've recently started hacking with Elisp, and I really like it. Parenthesis are obviously pretty awkward at first. But now I wouldn't leave them for anything else. As it turns out, the brackets make it easy for your editor to understand the semantics of your code, to a whole new level. So your editor is now actively helping you navigate and edit your code. You go from expressions to expressions, add one after an other, transpose them and their parameters, absorb other expressions, insert them etc. It's true magic. I thinks that's why some don't like the fact that CL-loop is not "lispy" enough: you lose your editor's help inside a CL loop. So the parents are actually really cool: you can basically tell your editor to move code around and insert / delete it instead of doing it yourself. With these tools (smart parents and paredit on emacs), your parenthesis are always matched ! And because it's lisp, you're actually forced to use these tools because it's a nightmare otherwise (which makes it kinda hard to learn at first), so you actually do learn them. I haven't used smartparents with other languages, but I hear it works pretty well. Finally, it seems that lisp dialects compile to almost anything. Which means that you can use a lisp editor and get all its benefits even when working in clojure on the JVM or clojurescript on the browser etc. And once you're good at lisp, you can pretty much make Emacs do anything. Conclusion: Lisp Is Pretty, give it a try when you get a chance ;) [0] https://github.com/Fuco1/smartparens https://github.com/Fuco1/smartparens EDIT: fixed some sentences so they make sense...
- bjoli 8y ago
  I also never really liked the loop macro. I vastly prefer the racket-style for loops over the loop macro. There are some odd corners where the loop macro is cleaner (destructuring bind),but that is achievable in racket as well. I still haven't actually had an occurrence when for/fold hasn't been enough for my special case needs.
  - lispm 8y ago
    If you need it, there is also an implementation of CL:LOOP for Racket.
taeric 8y ago
While deep inheritance hierarchies may seem like a great way of modelling your concepts when you have a blank slate, it’s a recipe for some extremely tight and non-obvious coupling that can deadlock refactoring attempts in later phases once those concepts have shifted and the original model is no longer a good fit. This is probably the best critique of nominal inheritance I've read. It really does capture the problem and nicely alludes to the struggle of arguing against an inheritance structure. That it usually starts with many benefits but can easily grow to a constraint.
- itwy 8y ago
  I kept trying reading this as a haiku.
  - taeric 8y ago
    Ha! Apologies. I gave a somewhat vain attempt at quoting so it would show on phones ok.
gnl 8y ago
For anyone who'd be interested in trying a Lisp (with Clojure probably being the most mainstream one at the moment) and who's been put off by the parens, paredit and/or Emacs: - Parinfer [https://shaunlebron.github.io/parinfer/ https://shaunlebron.github.io/parinfer/] - makes the parens follow indentation and vice versa and effectively makes them a non-issue at worst and a great advantage at best (you can combine it with paredit later on to perform all kinds of ninja magic when editing code) - Cursive [https://cursive-ide.com/ https://cursive-ide.com/] - a Clojure plugin for IntelliJ IDEA for a more 'just works' experience. Integrates parinfer, among other things, and is generally pretty great (I'm a happy customer). And last but not least - rainbow parens to keep nested expressions readable. Pretty much every Lisp editor has them more or less out of the box.
- AlainPicard 8y ago
  I would very much NOT recommend using something like parinfer; IMO if one is learning lisp, one ought not to try to avoid the parentheses, but rather learn the advantages of using them. So instead of parinfer, use paredit and learn the key bindings for moving up/down/formard one sexpr at a time. It's frustrating at first, but after a few days, you will never want to go back to line oriented languages.
  - gnl 8y ago
    Well, first of all let me emphasise again that it's not an either/or proposition, they work together perfectly fine. Personally I use paredit extensively and yes, going back to a language/environment without it feels like having to work with my hands tied behind my back, but I still make use of parinfer as well. Sometimes just deleting a couple of lines in Vim (IdeaVIM in my case) and knowing that parinfer will take care of the parens feels faster and more comfortable to me than using paredit. YMMV. And as far as beginners are concerned - for someone coming from an OOP/imperative programming/C-style syntax background, a LISP will seem very foreign and weird for many reasons, the parens being just one of them. I think having the ability to get your feet wet and start dabbling without an upfront investment is a good thing and the "jumping into the deep end" approach isn't for everyone, especially not for many beginners who at this point have only a very vague idea that a LISP might be for them and are already facing a number of new concepts that they need to get their heads around. Parinfer requires no investment, Paredit requires some. Not much, but still. And going from one to the other as one feels drawn to explore the language is, I think, a perfectly natural transition, which requires no unlearning or changing of habits whatsoever, and as such it's also a more accessible path to getting into LISP. In my book, that's a good thing. But here we're beginning to move into a general attitude/philosophy territory that's hard to argue about, so I'd be perfectly comfortable with agreeing to disagree and leaving it at that.
grzm 8y ago
(2015)

183 points by ghosthamlet 8y ago

This is part three. Part one: http://gmorpheme.net/lisp-in-small-pieces-of-clojure-part-1.html http://gmorpheme.net/lisp-in-small-pieces-of-clojure-part-1.... Part two: http://gmorpheme.net/lisp-in-small-pieces-of-clojure-part-2.html http://gmorpheme.net/lisp-in-small-pieces-of-clojure-part-2....

benjaminsuch 8y ago
That's whats mentioned right at the start of the article? This continues a translation of various parts of Lisp in Small Pieces into Clojure. For earlier chapters, see: Lisp in Small Pieces of Clojure - part 1. Lisp in Small Pieces of Clojure - part 2.

agumonkey 8y ago

I applaud joyfully.

cup-of-tea 8y ago

Oh this looks great. I loved L.I.S.P. I did plan to dust off my French and try the second edition. But I'm sure I'll enjoy this just as much.

nextos 8y ago
A testament about the quality of Lisp is the breadth and depth of its literature: SICP, PAIP, On Lisp, Lisp in Small Pieces, CLtL... The only great book I'd like to see written in Lisp is CTM.
- cylinder714 8y ago
  "CTM"?
  - sigjuice 8y ago
    https://mitpress.mit.edu/books/concepts-techniques-and-models-computer-programming https://mitpress.mit.edu/books/concepts-techniques-and-model...
  - deleted 8y ago
    [deleted]
- Lozzer 8y ago
  I'd add Let over Lambda (LOL) to that list.
aidenn0 8y ago
For those who are not francophones, there is also an English translation.

globuous 8y ago

Slightly unrelated, but to those who have never tried Lisp because of the parenthesis (like me until recently), here's my take: I've recently started hacking with Elisp, and I really like it. Parenthesis are obviously pretty awkward at first. But now I wouldn't leave them for anything else. As it turns out, the brackets make it easy for your editor to understand the semantics of your code, to a whole new level. So your editor is now actively helping you navigate and edit your code. You go from expressions to expressions, add one after an other, transpose them and their parameters, absorb other expressions, insert them etc. It's true magic. I thinks that's why some don't like the fact that CL-loop is not "lispy" enough: you lose your editor's help inside a CL loop. So the parents are actually really cool: you can basically tell your editor to move code around and insert / delete it instead of doing it yourself. With these tools (smart parents and paredit on emacs), your parenthesis are always matched ! And because it's lisp, you're actually forced to use these tools because it's a nightmare otherwise (which makes it kinda hard to learn at first), so you actually do learn them. I haven't used smartparents with other languages, but I hear it works pretty well. Finally, it seems that lisp dialects compile to almost anything. Which means that you can use a lisp editor and get all its benefits even when working in clojure on the JVM or clojurescript on the browser etc. And once you're good at lisp, you can pretty much make Emacs do anything. Conclusion: Lisp Is Pretty, give it a try when you get a chance ;) [0] https://github.com/Fuco1/smartparens https://github.com/Fuco1/smartparens EDIT: fixed some sentences so they make sense...

bjoli 8y ago
I also never really liked the loop macro. I vastly prefer the racket-style for loops over the loop macro. There are some odd corners where the loop macro is cleaner (destructuring bind),but that is achievable in racket as well. I still haven't actually had an occurrence when for/fold hasn't been enough for my special case needs.
- lispm 8y ago
  If you need it, there is also an implementation of CL:LOOP for Racket.

taeric 8y ago

While deep inheritance hierarchies may seem like a great way of modelling your concepts when you have a blank slate, it’s a recipe for some extremely tight and non-obvious coupling that can deadlock refactoring attempts in later phases once those concepts have shifted and the original model is no longer a good fit. This is probably the best critique of nominal inheritance I've read. It really does capture the problem and nicely alludes to the struggle of arguing against an inheritance structure. That it usually starts with many benefits but can easily grow to a constraint.

itwy 8y ago
I kept trying reading this as a haiku.
- taeric 8y ago
  Ha! Apologies. I gave a somewhat vain attempt at quoting so it would show on phones ok.

gnl 8y ago

For anyone who'd be interested in trying a Lisp (with Clojure probably being the most mainstream one at the moment) and who's been put off by the parens, paredit and/or Emacs: - Parinfer [https://shaunlebron.github.io/parinfer/ https://shaunlebron.github.io/parinfer/] - makes the parens follow indentation and vice versa and effectively makes them a non-issue at worst and a great advantage at best (you can combine it with paredit later on to perform all kinds of ninja magic when editing code) - Cursive [https://cursive-ide.com/ https://cursive-ide.com/] - a Clojure plugin for IntelliJ IDEA for a more 'just works' experience. Integrates parinfer, among other things, and is generally pretty great (I'm a happy customer). And last but not least - rainbow parens to keep nested expressions readable. Pretty much every Lisp editor has them more or less out of the box.

AlainPicard 8y ago
I would very much NOT recommend using something like parinfer; IMO if one is learning lisp, one ought not to try to avoid the parentheses, but rather learn the advantages of using them. So instead of parinfer, use paredit and learn the key bindings for moving up/down/formard one sexpr at a time. It's frustrating at first, but after a few days, you will never want to go back to line oriented languages.
- gnl 8y ago
  Well, first of all let me emphasise again that it's not an either/or proposition, they work together perfectly fine. Personally I use paredit extensively and yes, going back to a language/environment without it feels like having to work with my hands tied behind my back, but I still make use of parinfer as well. Sometimes just deleting a couple of lines in Vim (IdeaVIM in my case) and knowing that parinfer will take care of the parens feels faster and more comfortable to me than using paredit. YMMV. And as far as beginners are concerned - for someone coming from an OOP/imperative programming/C-style syntax background, a LISP will seem very foreign and weird for many reasons, the parens being just one of them. I think having the ability to get your feet wet and start dabbling without an upfront investment is a good thing and the "jumping into the deep end" approach isn't for everyone, especially not for many beginners who at this point have only a very vague idea that a LISP might be for them and are already facing a number of new concepts that they need to get their heads around. Parinfer requires no investment, Paredit requires some. Not much, but still. And going from one to the other as one feels drawn to explore the language is, I think, a perfectly natural transition, which requires no unlearning or changing of habits whatsoever, and as such it's also a more accessible path to getting into LISP. In my book, that's a good thing. But here we're beginning to move into a general attitude/philosophy territory that's hard to argue about, so I'd be perfectly comfortable with agreeing to disagree and leaving it at that.

grzm 8y ago

(2015)