A difference between Haskell and Common Lisp

#1

Post by psibi » Mon, Dec 21, 2015, 1:51 PM UTC

A difference between Haskell and Common Lisp
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Re: A difference between Haskell and Common Lisp

#2

Post by catnaroek » Mon, Dec 21, 2015, 2:22 PM UTC

The difference is not one of "philosophy", but rather of using the right types. Haskell's so-called "list" type constructor is actually a type constructor of streams. Unsurprisingly, streams are much better than lists if you want to do stream processing.

Re: A difference between Haskell and Common Lisp

#3

Post by fnordsensei » Mon, Dec 21, 2015, 2:28 PM UTC

Is this really a philosophical difference? Granted, I've only used Clojure as far as Lisps go, but composability seems to be something that's emphasized.

Rather than

   (remove-if-not #'p xs :count 5 :start 3)

It seems to me like most Clojure users would do something like

   (->> xs (drop 3) (filter p) (take 5))

which is much closer to

   take 5 . filter p . drop 3

Re: A difference between Haskell and Common Lisp

#4

Post by icholy » Mon, Dec 21, 2015, 2:31 PM UTC

fnordsensei wrote: post #3

Is this really a philosophical difference? Granted, I've only used Clojure as far as Lisps go, but composability seems to be something that's emphasized. Rather than (remove-if-not #'p xs :count 5 :start 3) It seems to me like most Clojure users would do something like (->> xs (drop 3) (filter p) (take 5)) which is much closer to take 5 . filter p . drop 3

Unlike CL/EL, Clojure is lazy by default. So it's closer to Haskell in that regard.

Re: A difference between Haskell and Common Lisp

#5

Post by grabcocque » Mon, Dec 21, 2015, 2:31 PM UTC

You have to be clear about which Lisp. Clojure and Scheme are Lisps, and their focus is very much towards simplicity and the use of combinators.

The complex, do-it-all-in-one-huge macro is a Common Lispism, not a Lispism.

Secondly, Clojure, like Haskell, is focused on sequence abstractions, not lists. Sequences can include collections, streams, observables, sockets and many other kinds of process that can be modelled as an event stream.

Re: A difference between Haskell and Common Lisp

#6

Post by tel » Mon, Dec 21, 2015, 2:31 PM UTC

icholy wrote: post #4

fnordsensei wrote: post #3

Is this really a philosophical difference? Granted, I've only used Clojure as far as Lisps go, but composability seems to be something that's emphasized. Rather than (remove-if-not #'p xs :count 5 :start 3) It seems to me like most Clojure users would do something like (->> xs (drop 3) (filter p) (take 5)) which is much closer to take 5 . filter p . drop 3

Unlike CL/EL, Clojure is lazy by default. So it's closer to Haskell in that regard.

It's not really lazy by default, it just has a lazy stream type with nice syntax.

Re: A difference between Haskell and Common Lisp

#7

Post by catnaroek » Mon, Dec 21, 2015, 2:31 PM UTC

icholy wrote: post #4

fnordsensei wrote: post #3

Is this really a philosophical difference? Granted, I've only used Clojure as far as Lisps go, but composability seems to be something that's emphasized. Rather than (remove-if-not #'p xs :count 5 :start 3) It seems to me like most Clojure users would do something like (->> xs (drop 3) (filter p) (take 5)) which is much closer to take 5 . filter p . drop 3

Unlike CL/EL, Clojure is lazy by default. So it's closer to Haskell in that regard.

Clojure isn't lazy by default. It is a strict language with lazy streams in the standard library.

Re: A difference between Haskell and Common Lisp

#8

Post by icholy » Mon, Dec 21, 2015, 2:33 PM UTC

catnaroek wrote: post #7

icholy wrote: post #4

Earlier quoted context omitted.

Unlike CL/EL, Clojure is lazy by default. So it's closer to Haskell in that regard.

Clojure isn't lazy by default. It is a strict language with lazy streams in the standard library.

Sorry, yes. That's what I meant.

Re: A difference between Haskell and Common Lisp

#9

Post by PuercoPop » Mon, Dec 21, 2015, 2:35 PM UTC

Minor nitpick. The loop at the end could make the range by 'for i from 1 upto 4' instead of a list literal to more similar to the haskell code.

Re: A difference between Haskell and Common Lisp

#10

Post by catnaroek » Mon, Dec 21, 2015, 2:37 PM UTC

fnordsensei wrote: post #3

Is this really a philosophical difference? Granted, I've only used Clojure as far as Lisps go, but composability seems to be something that's emphasized. Rather than (remove-if-not #'p xs :count 5 :start 3) It seems to me like most Clojure users would do something like (->> xs (drop 3) (filter p) (take 5)) which is much closer to take 5 . filter p . drop 3

Minor nitpick. Technically, this:

    #(->> % (drop 3) (filter p) (take 5))

Is equivalent to:

    take 5 . filter p . drop 3