src/compile/literal.js
function(literal) {
      var val = literal.value;
      var ret = val;

      if (literal.isEval && (val.indexOf('#') !== -1 ||
            val.indexOf("$") !== -1)) {
        ret = this.evalStr(val);
      }

      return ret;
    }
function(literal) {
      var val = literal.value;
      var ret = val;

      if (literal.isEval && (val.indexOf('#') !== -1 ||
            val.indexOf("$") !== -1)) {
        ret = this.evalStr(val);
      }

      return ret;
    }
function ( literal ) { var val = literal . value ; var ret = val ; if ( literal . isEval && ( val . indexOf ( '#' ) !== - 1 || val . indexOf ( "$" ) !== - 1 ) ) { ret = this . evalStr ( val ) ; } return ret ; }
对字符串求值，对已双引号字符串，需要做变量替换
对字符串求值，对已双引号字符串，需要做变量替换