Split a command-line to an array

split_command.js

var splitCommand = (function(){
  function State(text) {
    this.args = [];
    this.term = '';
    this.quot = null;
    this.next = null;

    ['split', 'quoted', 'interm', 'escape'].map(function(m){
      this[m] = function(at){
        at++;
        if (at < text.length) {
          return this['_'+m](text.charAt(at), at);
        }
        if (this.term != '') this.termed();
        return this.args;
      }.bind(this);
    }.bind(this));
  }

  State.prototype._split = function (char, at) {
    switch(char) {
      case ' ':
        return this.split(at);
      case '"':
      case "'":
        this.quot = char;
        return this.quoted(at);
      case '\\':
        this.next = this.interm;
        return this.escape(at);
      default:
        this.term += char;
        return this.interm(at);
    }
  };

  State.prototype._quoted = function (char, at) {
    switch(char) {
      case this.quot:
        this.termed();
        return this.split(at);
      case '\\':
        this.next = this.quoted;
        return this.escape(at);
      default:
        this.term += char;
        return this.quoted(at);
    }
  };

  State.prototype._interm = function (char, at) {
    switch(char) {
      case ' ':
        this.termed();
        return this.split(at);
      case '\\':
        this.next = this.interm;
        return this.escape(at);
      default:
        this.term += char;
        return this.interm(at);
    }
  };

  State.prototype._escape = function (char, at) {
    this.term += char;
    return this.next(at);
  };

  State.prototype.termed = function() {
    this.args.push(this.term);
    this.term = '';
  };

  return function(text) {
    return new State(text).split(-1);
  }
})();

//console.log(splitCommand('hogehoge "" "\\\\" "\\" hoge" "  \\"  " "\\""'));