tlrobinson/LICENSE.txt

## README.md

      
    Raw
  

              README.md
            
          
    Prefix notation calculator interpreter

This is a very simple prefix notation calculator implementation in JavaScript, for the purpose of demonstrating a simple lexer, parser, compiler, and interpreter for my JSConf.eu talk, "JavaScript Compilers for Fun and Profit".
They're available packaged together here:

https://gist.github.com/1257254

mini-calc-golfed.js contains each component JS-golfed down to < 140 bytes.
And individually as 140byt.es forks here:

Lexer: https://gist.github.com/1259461
Parser: https://gist.github.com/1259487
Interpreter: https://gist.github.com/1259489
Compiler: https://gist.github.com/1259490


## annotated.js
function(node) {
    if (Array.isArray(node)) {
        // first element is the function, rest are the arguments
        var fn = interpret(node[0]);
        var args = node.slice(1).map(interpret);
        return fn.apply(null, args);
    } else if (typeof node === "number") {
        // number literal
        return node;
    } else {
        // lookup symbols in the environment object
        return environment[node];
    }
}

## index.js
function(n){if(Array.isArray(n)){n=n.map(i);return n[0].apply(null,n.slice(1))}else{return typeofn=="number"?n:e[n]}}

## LICENSE.txt
            DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
                    Version 2, December 2004

 Copyright (C) 2011 Tom Robinson <http://tlrobinson.net/>

 Everyone is permitted to copy and distribute verbatim or modified
 copies of this license document, and changing it is allowed as long
 as the name is changed.

            DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION

  0. You just DO WHAT THE FUCK YOU WANT TO.

## package.json
{
  "name": "theNameOfYourLibWhichMustBeAValidCamelCasedJavaScriptIdentifier",

  "description": "This should be a short description of your entry.",

  "keywords": [
    "five",
    "descriptive",
    "keywords",
    "or",
    "fewer"
  ]
}

## test.html
<!DOCTYPE html>
<title>Prefix notation calculator interpreter</title>
<script>
    function repl(c,t,h,r){h=[t||""];while(s=prompt(h.slice(-10).join("\n"))){try{r=(c||eval)(s)}catch(e){r=e}h.push(""+r)}}

    // lexer
    function l(s){return s.match(/\(|\)|\d+(\.\d+)?|\w+|[+*\/-]/g).map(function(t){return /^\d/.test(t)?parseFloat(t):t})}
    // parser
    function p(a,b,c){c=[];a.shift();while(b=a.shift()){if(b=="("){a.unshift(b);c.push(p(a))}else if(b==")"){return c}else{c.push(b)}}}
    // interpreter
    function i(n){if(Array.isArray(n)){n=n.map(i);return n[0].apply(null,n.slice(1))}else{return typeofn=="number"?n:e[n]}}

    repl(function(s) { return i(p(l(s))); }, "Prefix notation calculator interpreter, e.x. '(+ 1 (* 2 3))'")
</script>
	function(node) {
	if (Array.isArray(node)) {
	// first element is the function, rest are the arguments
	var fn = interpret(node[0]);
	var args = node.slice(1).map(interpret);
	return fn.apply(null, args);
	} else if (typeof node === "number") {
	// number literal
	return node;
	} else {
	// lookup symbols in the environment object
	return environment[node];
	}
	}
	DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
	Version 2, December 2004

	Copyright (C) 2011 Tom Robinson <http://tlrobinson.net/>

	Everyone is permitted to copy and distribute verbatim or modified
	copies of this license document, and changing it is allowed as long
	as the name is changed.

	DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
	TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION

	0. You just DO WHAT THE FUCK YOU WANT TO.
	{
	"name": "theNameOfYourLibWhichMustBeAValidCamelCasedJavaScriptIdentifier",

	"description": "This should be a short description of your entry.",

	"keywords": [
	"five",
	"descriptive",
	"keywords",
	"or",
	"fewer"
	]
	}
	<!DOCTYPE html>
	<title>Prefix notation calculator interpreter</title>
	<script>
	function repl(c,t,h,r){h=[t\|\|""];while(s=prompt(h.slice(-10).join("\n"))){try{r=(c\|\|eval)(s)}catch(e){r=e}h.push(""+r)}}

	// lexer
	function l(s){return s.match(/\(\|\)\|\d+(\.\d+)?\|\w+\|[+*\/-]/g).map(function(t){return /^\d/.test(t)?parseFloat(t):t})}
	// parser
	function p(a,b,c){c=[];a.shift();while(b=a.shift()){if(b=="("){a.unshift(b);c.push(p(a))}else if(b==")"){return c}else{c.push(b)}}}
	// interpreter
	function i(n){if(Array.isArray(n)){n=n.map(i);return n[0].apply(null,n.slice(1))}else{return typeofn=="number"?n:e[n]}}

	repl(function(s) { return i(p(l(s))); }, "Prefix notation calculator interpreter, e.x. '(+ 1 (* 2 3))'")
	</script>