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Show HN: a Lisp that uses JSON instead of S-expressions (in .js)

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Re: Show HN: a Lisp that uses JSON instead of S-expressions (in .js)

#11

Post by jes5199 »

benatkin wrote: post #7
oconnor0 wrote: post #5

Does it use more JSON data types than arrays? The only examples are ["map", ....] I don't see any `{ }`, etc.

There is only one other composite data type besides arrays: objects. I don't think these are being used for invoking functions, but I think it would be interesting to try.

An idea that I had was to use Objects to define namespaces, like when writing a library:

  {
    "myFunction": ["lambda", ...],
    "myFunction2": ["lambda", ...],
  }
I can't decide if it has any advantage over the traditional "define" function, though.

Re: Show HN: a Lisp that uses JSON instead of S-expressions (in .js)

#13

Post by yangyang »

xyzzyz wrote: post #9

I'm sorry, but I cannot get excited over Yet Another Implementation of McCarthy's LISP[1]. If your Lisp had _any_ interesting feature, e.g. call/cc, or object system, or nifty macro system, or something else, then, maybe, but doing the the same old, trivial thing, again and again, does not seem very interesting for me. We don't usually see yet another Brainfuck interpreter, or yet another Fibonacci queue implementati…

Because it's pretty straightforward - there's very little parsing involved (in this case basically none).

Re: Show HN: a Lisp that uses JSON instead of S-expressions (in .js)

#14

Post by jes5199 »

xyzzyz wrote: post #9

I'm sorry, but I cannot get excited over Yet Another Implementation of McCarthy's LISP[1]. If your Lisp had _any_ interesting feature, e.g. call/cc, or object system, or nifty macro system, or something else, then, maybe, but doing the the same old, trivial thing, again and again, does not seem very interesting for me. We don't usually see yet another Brainfuck interpreter, or yet another Fibonacci queue implementati…

I didn't claim it was revolutionary, I just keep hearing LISP hackers say "there's no reason to care about XML or JSON if you've got S-Expressions, which are so much cleaner"

This project is exercising (proving? refuting?) that claim. I recognize that this isn't the most ambitious project in the world, but it was a Thanksgiving-weekend hack.

I'm thrilled that it got the 20 votes necessary to get it on the front page of HN.

Re: Show HN: a Lisp that uses JSON instead of S-expressions (in .js)

#15

Post by cyrus_ »

gruseom wrote: post #8

I still think there's room for experimenting with a Lisp that has the hashmap (a.k.a. dictionary, associative array, property bag) as its organizing principle rather than the list. There's nothing better than hashmaps for exploratory programming. If there is something to be gained from building a Lisp in terms of them (from the ground up; I don't mean support for object literals), I'd like to know what it is. This ha…

You could argue that Javascript is a language with the hashmap as its central data structure. It doesn't have a macro system/quotations/other LISPy things, of course, but you can certainly frame your argument as "would JS benefit from ?"

Re: Show HN: a Lisp that uses JSON instead of S-expressions (in .js)

#16

Post by ohyes »

ktusznio wrote: post #12

What is the purpose of the "quote" parameter? The only place it is in the code is here: else if(x[0] == 'quote'){ return x[1]; So why not just skip that extra verbosity? What am I missing?

Quote prevents evaluation. If you didn't quote it, x[1] would get evaluated as code.

Re: Show HN: a Lisp that uses JSON instead of S-expressions (in .js)

#18

Post by lisper »

jes5199 wrote: post #14
xyzzyz wrote: post #9

I'm sorry, but I cannot get excited over Yet Another Implementation of McCarthy's LISP[1]. If your Lisp had _any_ interesting feature, e.g. call/cc, or object system, or nifty macro system, or something else, then, maybe, but doing the the same old, trivial thing, again and again, does not seem very interesting for me. We don't usually see yet another Brainfuck interpreter, or yet another Fibonacci queue implementati…

I didn't claim it was revolutionary, I just keep hearing LISP hackers say "there's no reason to care about XML or JSON if you've got S-Expressions, which are so much cleaner" This project is exercising (proving? refuting?) that claim. I recognize that this isn't the most ambitious project in the world, but it was a Thanksgiving-weekend hack. I'm thrilled that it got the 20 votes necessary to get it on the front page…

I vote for "prove". All those extra and unnecessary quotes and commas. Blech. And all that extra ugliness just so you can re-use the JS parser? IMHO there's no excuse for this. It's really easy to write a parser that does the Right Thing, e.g.:

http://www.flownet.com/ron/lisp/l.py

Re: Show HN: a Lisp that uses JSON instead of S-expressions (in .js)

#19

Post by lisper »

gruseom wrote: post #8

I still think there's room for experimenting with a Lisp that has the hashmap (a.k.a. dictionary, associative array, property bag) as its organizing principle rather than the list. There's nothing better than hashmaps for exploratory programming. If there is something to be gained from building a Lisp in terms of them (from the ground up; I don't mean support for object literals), I'd like to know what it is. This ha…

This presents a very thorny language design problem. Lists have this very nice property that they are ordered, which lets you attach implied semantics to the position of an element, e.g.:

(defun foo (a b c) ...)

We know this is a function defining because the symbol DEFUN is in the FIRST position of the list.

Associative arrays are unordered, so you have to explicitly label everything:

{ top-level-form : defun, arguments : { 1 : a, 2 : b, 3 : c }, ... }

Or something like that. You can see where that would get annoying.

Exercise for the reader: what happens if you base a Lisp-like language on vectors instead of cons cells?

Re: Show HN: a Lisp that uses JSON instead of S-expressions (in .js)

#20

Post by raganwald »

xyzzyz wrote: post #9

I'm sorry, but I cannot get excited over Yet Another Implementation of McCarthy's LISP[1]. If your Lisp had _any_ interesting feature, e.g. call/cc, or object system, or nifty macro system, or something else, then, maybe, but doing the the same old, trivial thing, again and again, does not seem very interesting for me. We don't usually see yet another Brainfuck interpreter, or yet another Fibonacci queue implementati…

(cranky

You know, we have the upvote arrow for things that excite you, and the “Go read something else and comment on it” feature for things that don’t float your boat.

Clearly this is not spam and it is not off-topic. So:

You asked the OP and/or your fellow HNers why they upvoted this onto the front page. I ask you, why this comment, what value does it add to my life to read about how smart and educated you are?

What about all the people who haven’t seen an implementation of McCarthy’s Lisp? Do they not deserve to find this interesting? Should they turn in their HN accounts and head over to reddit?

I wrote an implementation of Scheme in Java with macros, tail call optimization, lambda hoisting, a bunch of stuff. Yet I find this interesting. Is there something wrong with me?

)

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