node.js中的querystring.unescape方法使用说明

          state = ‘CHAR’;
          break;
        }
        break;
      case ‘HEX1’:
        state = ‘CHAR’;
        if (charCode(‘0’) <= c && c <= charCode(‘9’)) {
          m = c – charCode(‘0’);
        } else if (charCode(‘a’) <= c && c <= charCode(‘f’)) {
          m = c – charCode(‘a’) + 10;
        } else if (charCode(‘A’) <= c && c <= charCode(‘F’)) {
          m = c – charCode(‘A’) + 10;
        } else {
          out[outIndex++] = charCode(‘%’);
          out[outIndex++] = hexchar;
          out[outIndex++] = c;
          break;
        }
        out[outIndex++] = 16 * n + m;
        break;
    }
  }
  // TODO support returning arbitrary buffers.
  return out.slice(0, outIndex – 1);
};