Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Lisp is Abstract Syntax

michaelrbernste.in

Post reply on HN
Print view View original

51–55 of 55 posts

Re: Lisp is Abstract Syntax

#51

Post by hga »

lispm wrote: post #48
minikomi wrote: post #44

Earlier quoted context omitted.

In learning Clojure first then Racket, it struck me how many good ideas came from racket.. and now how many are still being mined - typed racket being the obvious one.

I don't know how much Rich Hickey used Racket, but he used Common Lisp for several years and wrote some complex libaries for it. There is also a sketch of Clojure early on written in Common Lisp.

Racket started out as a Scheme, and Clojure has mined quite a bit from Scheme. Both are Lisp-1s, loop/recur, not accepting a lot of mainline LISP (e.g. Common Lisp nowadays) baggage, etc.

Re: Lisp is Abstract Syntax

#52

Post by brudgers »

minikomi wrote: post #44
brudgers wrote: post #31

Earlier quoted context omitted.

I'm a fan of Rich Hickey, too. And I think Clojure is a solid language. But I wouldn't suggest Clojure as the entry point when seeking a overall understanding of Lisp. There's too much baggage and history swirling around it for explanations ever to be comfortable - e.g. even if Rich Hickey always makes convincing arguments, it's important to note that they are always arguments. That is there always seems to be at lea…

In learning Clojure first then Racket, it struck me how many good ideas came from racket.. and now how many are still being mined - typed racket being the obvious one.

That's the advantage of Racket's close relationship with academia...'Implementing x in Racket' is publishable and 'A y Library for Racket' is a Master's Degree project.

Re: Lisp is Abstract Syntax

#53

Post by lispm »

hga wrote: post #51
lispm wrote: post #48

Earlier quoted context omitted.

I don't know how much Rich Hickey used Racket, but he used Common Lisp for several years and wrote some complex libaries for it. There is also a sketch of Clojure early on written in Common Lisp.

Racket started out as a Scheme, and Clojure has mined quite a bit from Scheme. Both are Lisp-1s, loop/recur, not accepting a lot of mainline LISP (e.g. Common Lisp nowadays) baggage, etc.

Actually there is not much Clojure got from Scheme. Lisp 1 is not tied to Scheme. loop/recur is much less powerful than Scheme's TCO.

Re: Lisp is Abstract Syntax

#54

Post by hga »

lispm wrote: post #53
hga wrote: post #51

Earlier quoted context omitted.

Racket started out as a Scheme, and Clojure has mined quite a bit from Scheme. Both are Lisp-1s, loop/recur, not accepting a lot of mainline LISP (e.g. Common Lisp nowadays) baggage, etc.

Actually there is not much Clojure got from Scheme. Lisp 1 is not tied to Scheme. loop/recur is much less powerful than Scheme's TCO.

Lisp-1 is pretty firmly tied in most people's minds to Scheme: at the very least the paper that coined the terms (http://www.nhplace.com/kent/Papers/Technical-Issues.html) ascribed it to Scheme, and as far as I know it first came from Scheme (although it's so easy to create a low performance Lisp I wouldn't be surprised if that had been tried before).

loop/recur is of course much less powerful than TCO, because the JVM doesn't natively support it (it's not trivial, security wise). There are three other Lisps on the JVM that I know of: SISC Scheme is mostly dead but does TCO at a cost in speed, Kawa Scheme has as of late added fine grain control over TCO, and Armed Bear Common Lisp doesn't try, as Common Lisps are not required to.

But loop/recur sure looks to be ultimately inspired by Scheme style use of TCO; I just did a set of functions using it for the first time and everything I learned from SICP/6.001 applied and made that part of it trivial.

Re: Lisp is Abstract Syntax

#55

Post by lispm »

hga wrote: post #54
lispm wrote: post #53

Earlier quoted context omitted.

Actually there is not much Clojure got from Scheme. Lisp 1 is not tied to Scheme. loop/recur is much less powerful than Scheme's TCO.

Lisp-1 is pretty firmly tied in most people's minds to Scheme: at the very least the paper that coined the terms ( http://www.nhplace.com/kent/Papers/Technical-Issues.html ) ascribed it to Scheme, and as far as I know it first came from Scheme (although it's so easy to create a low performance Lisp I wouldn't be surprised if that had been tried before). loop/recur is of course much less powerful than TCO, because the…

Haskell also has only one namespace. I propose that Clojure took it from there, including persistent data structures, lazy data structures, ...

> But loop/recur sure looks to be ultimately inspired by Scheme style use of TCO;

To me it looks more like ancient Lisp with prog and goto.

    (defun foo ()
      (prog ((a 1))
        start
        (print a)
        (when (
Old Lisp code is full of that. It's basically what LOOP/RECUR provides.
Post reply on HN