Brainfuck139

README.md

This is a Brainfuck implementation in just 139 chars of JavaScript. Works only in Firefox. For a Cross-Browser compatible version see below.

Usage: f( string, callback)
string is the brainfuck code you want to be executed
callback is a reference to a function.

since JavaScript has no stdio the callback will be called on . with the binary value of the current cell as only parameter. For the same reason , is unsupported.

Examples:

f("++.", alert) // alerts 2
f("+++.[->+<]>.", alert) // alerts 3 and 3
f("++++++++++[>+++++++>++++++++++>+++>+<<<<-]>++.>+.+++++++..+++.>++."+  
  "<<+++++++++++++++.>+++.------.--------.>+.>.+++.",console.log.bind(console)) 
  // logs the ascii of "Hello World!\n"

function buffer(){
    var a = [];
    return {
        add: function(b){
            a.push(b);
        },
        flush: function(){
            console.log( String.fromCharCode.apply(String,a));
        },
        clear: function(){
            a=[];
        }
    };
}
var b=buffer();
f("++++++++++[>+++++++>++++++++++>+++>+<<<<-]>++.>+.+++++++..+++.>++."+  
  "<<+++++++++++++++.>.+++.------.--------.>+.>.+++.",b.add);
b.flush() // logs "Hello World!\n"

// compatible, 148 chars:
function f(a,b,c){return c?{"]":"}","[":"while(a[c]){",".":"b(a[c]);","<":"c--;",">":"c++;"}[a]||"a[c]=~~a[c]"+a+"1;":eval(a.replace(a=/./g,f,c=0))}

Fell free to fuck around and send me a note when you are done or have any suggestions.

mfG Hase

annotated.js

function f(    // NFE for self passing
  a,           // the brainfuck source code to convert
  b,           // the callback
  c            // will be truthy when called via replace
) c ?          // note the firefox only function expression
{ // micromode: a is a single char
  "]": "}",    // maps the brainfuck instructions to JS statements
  "[": "while(a[c]){",
  ".": "b(a[c]);",
  "<": "c--;",
  ">": "c++;"
}[a] || 
  "a[c]=~~a[c]"+// ~~a[c] converts a[c] into an integer ie. undefined -> 0
  a + "1;"     // if the current char is + or - map them to `a[c]=~~a[c]+1;`.
: // macromode: a is the brainfuck source
  eval(        // eval the compiled code in the current scope!!!
    a.replace( // take the source and replace it char by char
      a=/./g,  // 1) replace one char at a time
               // 2) use the regex as an object for the array
      f,       // change to micro mode for the individual char
      c=0      // this has no effect for a.replace() its just a good place to set c to 0.
    )
  // execution mode: a is the "array"
  // c is the pointer and b the callback
  )

index.js

function f(a,b,c)c?{"]":"}","[":"while(a[c]){",".":"b(a[c]);","<":"c--;",">":"c++;"}[a]||"a[c]=~~a[c]"+a+"1;":eval(a.replace(a=/./g,f,c=0))

//ES6, 130chars
(a,b,c)=>eval(a.replace(a=/./g,a=>(["a[c]=~~a[c]"+a+"1;","}","while(a[c]){","b(a[c]);","c--;","c++;"]["][.<>".indexOf(a)+1]),c=0))

LICENSE.txt

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

 Copyright (C) 2011 Kambfhase

 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": "brainfuck139",

  "description": "brainfuck in 139 bytes",

  "keywords": [
    "139bytes",
    "brainfuck",
    "firefox only"
  ]
}

Very nice