function(file) {
    debug('lexing <%s>', this.file.path);
    if (file) this.file = file;
    this.init();
    while (this.input) this.next();
    return this.ast;
  }
function(file) {
    debug('lexing <%s>', this.file.path);
    if (file) this.file = file;
    this.init();
    while (this.input) this.next();
    return this.ast;
  }
function ( file ) { debug ( 'lexing <%s>' , this . file . path ) ; if ( file ) this . file = file ; this . init ( ) ; while ( this . input ) this . next ( ) ; return this . ast ; }
Tokenize the given string.
@return {Array}
Tokenize the given string .