User:Brooke Vibber/Gadget-ParserPlayground-jsdiff.js

/* * Javascript Diff Algorithm * By John Resig (http://ejohn.org/) * Modified by Chu Alan "sprite" * * Released under the MIT license. * * More Info: * http://ejohn.org/projects/javascript-diff-algorithm/ */

function escape(s) { var n = s;   n = n.replace(/&/g, "&amp;"); n = n.replace(//g, "&gt;"); n = n.replace(/"/g, "&quot;");

return n; }

function diffString( o, n ) { o = o.replace(/\s+$/, ''); n = n.replace(/\s+$/, '');

var out = diff(o == "" ? [] : o.split(/\s+/), n == "" ? [] : n.split(/\s+/) ); var str = "";

var oSpace = o.match(/\s+/g); if (oSpace == null) { oSpace = ["\n"]; } else { oSpace.push("\n"); } var nSpace = n.match(/\s+/g); if (nSpace == null) { nSpace = ["\n"]; } else { nSpace.push("\n"); }

if (out.n.length == 0) { for (var i = 0; i < out.o.length; i++) { str += ' ' + escape(out.o[i]) + oSpace[i] + " "; } } else { if (out.n[0].text == null) { for (n = 0; n < out.o.length && out.o[n].text == null; n++) { str += ' ' + escape(out.o[n]) + oSpace[n] + " "; }   }

for ( var i = 0; i < out.n.length; i++ ) { if (out.n[i].text == null) { str += ' ' + escape(out.n[i]) + nSpace[i] + " "; } else { var pre = "";

for (n = out.n[i].row + 1; n < out.o.length && out.o[n].text == null; n++ ) { pre += ' ' + escape(out.o[n]) + oSpace[n] + " "; }       str += " " + escape(out.n[i].text) + nSpace[i] + pre; }   }  }  return str; }

function randomColor { return "rgb(" + (Math.random * 100) + "%, " +                    (Math.random * 100) + "%, " +                     (Math.random * 100) + "%)"; } function diffString2( o, n ) { o = o.replace(/\s+$/, ''); n = n.replace(/\s+$/, '');

var out = diff(o == "" ? [] : o.split(/\s+/), n == "" ? [] : n.split(/\s+/) );

var oSpace = o.match(/\s+/g); if (oSpace == null) { oSpace = ["\n"]; } else { oSpace.push("\n"); } var nSpace = n.match(/\s+/g); if (nSpace == null) { nSpace = ["\n"]; } else { nSpace.push("\n"); }

var os = ""; var colors = new Array; for (var i = 0; i < out.o.length; i++) { colors[i] = randomColor;

if (out.o[i].text != null) { os += '' + escape(out.o[i].text) + oSpace[i] + " "; } else { os += " " + escape(out.o[i]) + oSpace[i] + " "; } }

var ns = ""; for (var i = 0; i < out.n.length; i++) { if (out.n[i].text != null) { ns += '' + escape(out.n[i].text) + nSpace[i] + " "; } else { ns += " " + escape(out.n[i]) + nSpace[i] + " "; } }

return { o : os, n : ns }; }

function diff( o, n ) { var ns = new Object; var os = new Object; for ( var i = 0; i < n.length; i++ ) { if ( ns[ n[i] ] == null ) ns[ n[i] ] = { rows: new Array, o: null }; ns[ n[i] ].rows.push( i ); } for ( var i = 0; i < o.length; i++ ) { if ( os[ o[i] ] == null ) os[ o[i] ] = { rows: new Array, n: null }; os[ o[i] ].rows.push( i ); } for ( var i in ns ) { if ( ns[i].rows.length == 1 && typeof(os[i]) != "undefined" && os[i].rows.length == 1 ) { n[ ns[i].rows[0] ] = { text: n[ ns[i].rows[0] ], row: os[i].rows[0] }; o[ os[i].rows[0] ] = { text: o[ os[i].rows[0] ], row: ns[i].rows[0] }; } }  for ( var i = 0; i < n.length - 1; i++ ) { if ( n[i].text != null && n[i+1].text == null && n[i].row + 1 < o.length && o[ n[i].row + 1 ].text == null &&         n[i+1] == o[ n[i].row + 1 ] ) { n[i+1] = { text: n[i+1], row: n[i].row + 1 }; o[n[i].row+1] = { text: o[n[i].row+1], row: i + 1 }; } }  for ( var i = n.length - 1; i > 0; i-- ) { if ( n[i].text != null && n[i-1].text == null && n[i].row > 0 && o[ n[i].row - 1 ].text == null &&         n[i-1] == o[ n[i].row - 1 ] ) { n[i-1] = { text: n[i-1], row: n[i].row - 1 }; o[n[i].row-1] = { text: o[n[i].row-1], row: i - 1 }; } }  return { o: o, n: n }; }