Extract suffix array from string.

suffix_array.js

var suffix_array = (function(str){

  var create_suffixes = function(arg_str) {
    var suffixes = [];
    for (var i=0, length=arg_str.length; i<length; i+=1) {
      var work="";
      for (var j=i; j<length; j+=1) {
        work+=arg_str.charAt(j);
      }
      suffixes[i] = {string:work, index:i};
    }
    return suffixes;
  };

  return function(str) {
    var suffixes_array=[];
    var suffixes = create_suffixes(str);

    suffixes.sort(function(a,b) {
      return a.string>b.string ? 1 : -1;
    });

    for (var i=0, length=str.length; i<length; i+=1) {
      suffixes_array[i]=suffixes[i].index;
    }
    return suffixes_array;
  };

})(str);