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Comment by devijvers | Hacker News Reader

Thanks for the reference to Parenscript which I'm unfamiliar with. The main point of lisp.js is to benefit from node.js' event-loop/non-blocking-i/o environment. node.js will be able to handle far greater loads than web servers that use blocking I/O. I'm not sure whether or not the Common Lisp web server exclusively uses non-blocking I/O on the account that I'm not familiar with that web server. I'm erring on the side of blocking I/O in which case node.js/lisp.js would run circles around that web server.

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Using Parenscript with Node.js would presumably mean throwing out any Common Lisp web server and relying on Node to do the I/O. Otherwise, as you point out, you don't get much benefit from Node. In such a setup, Node (or Node behind a reverse proxy) would be the web server, Parenscript code compiled to JS would do whatever was needed in Node, and if you wanted application logic in a Lisp at runtime, you could call it however Node does IPC.

The value that Parenscript adds here is the same as for programs that run in a web browser: you write your JS in a Lispy way at a higher level of abstraction, mostly because you get the full power of Lisp macros. There are other wins too, but that's the big one. The runtime environment, though, is entirely JS, because PS is a compiler that targets JS.

So I still don't see a difference in intent here between what PS is good for and what you're doing. I don't want to discourage you at all. Just curious about the differentiator.

I've scanned the Parenscript docs and it doesn't seem immediately obvious how to combine node.js and Parenscript without having to include Common Lisp. Also, there's a number of things on my wish list that compelled me to write my own lisp implementation (there are other JavaScript lisp implementations):

* only requirement is node.js and the lisp source distribution, no other dependencies. * ability to debug lisp code from the browser. * immutable data structures.

I feel I can implement a lisp that can run the examples in <i>Let Over Lambda</i> in a couple of weeks. The lisp won't be as stable as Parenscript but that's ok. Only at that point can the real work start of building the web framework that is lisp.js. I think the most important bit for me is to have a base that I can modify as the needs arise. I'm already trying to include as many lisp concepts in the test source as I can find to make sure lisp.js is a general purpose lisp. In that respect I'm setting several goals: get lisp-in-lisp working, get Let Over Lambda examples working, ... any other useful lisp constructs that I come across. That's a journey I can only make if I do my own lisp implementation.

Regarding using NodeJS with ParenScript: it is really easy.

I am using Node on the backend of http://tryparenscript.com/ simply because it was easier to get up and running than Hunchentoot. Source code is on GitHub, if you want to check it out: http://github.com/fitzgen/tryparenscript.com

Here is the "Hello, WOrld!" example from the NodeJS homepage in ParenScript:

    (defvar *http* (require "http"))
    (chain *http*
           (create-server (lambda (req res)
                            ((@ res write-head) 200
                                                (create "Content-Type"
                                                        "text/plain"))
                            ((@ res end) "Hello, World!\n")))
           (listen 8124 "127.0.0.1"))
    ((@ console log) "Server running at http://127.0.0.1:8124/")

Far be it from me to stand between a programmer and his own Lisp implementation.

I'd love your help on sibilant; I started it with exactly the same motivation.

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