lib/parser.js
function(){
    var node = this.supportsNegation()
      || this.supportsOp();
    if (!node) {
      this.cond = true;
      node = this.expression();
      this.cond = false;
    }
    return node;
  }
function(){
    var node = this.supportsNegation()
      || this.supportsOp();
    if (!node) {
      this.cond = true;
      node = this.expression();
      this.cond = false;
    }
    return node;
  }
function ( ) { var node = this . supportsNegation ( ) || this . supportsOp ( ) ; if ( ! node ) { this . cond = true ; node = this . expression ( ) ; this . cond = false ; } return node ; }
supports negation
| supports op
| expression
supports negation | supports op | expression