• escape.js

  • ¶

    Escape nodes are used for escape sequences. It is rendered as a label with the description of the escape and the numeric code it matches when appropriate.

    import _ from 'lodash';

function hex(value) {
  var str = value.toString(16).toUpperCase();

  if (str.length < 2) {
    str = '0' + str;
  }

  return `(0x${str})`;
}

export default {
  type: 'escape',
  • ¶

    Renders the escape into the currently set container.

      _render() {
    return this.renderLabel(this.label)
      .then(label => {
        label.select('rect').attr({
          rx: 3,
          ry: 3
        });
        return label;
      });
  },

  setup() {
    let addHex;
  • ¶

    The escape code. For an escape such as \b it would be “b”.

        this.code = this.properties.esc.properties.code.textValue;
  • ¶

    The argument. For an escape such as \xab it would be “ab”.

        this.arg = this.properties.esc.properties.arg.textValue;
  • ¶

    Retrieves the label, ordinal value, an flag to control adding hex value from the escape code mappings

        [this.label, this.ordinal, addHex] = _.result(this, this.code);
  },
  • ¶

    Escape code mappings

      b: ['单词边界', -1, false],
  B: ['非单词边界', -1, false],
  d: ['数字', -1, false],
  D: ['非数字', -1, false],
  f: ['换页符', -1, true],
  n: ['换行符', -1, true],
  r: ['回车符', -1, true],
  s: ['空白字符', -1, false],
  S: ['非空白字符', -1, false],
  t: ['水平制表符', -1, true],
  v: ['垂直制表符', -1, true],
  w: ['单词', -1, false],
  W: ['非单词', -1, false],
  1: ['向后引用 (普通分组 = 1)', -1, false],
  2: ['向后引用 (普通分组 = 2)', -1, false],
  3: ['向后引用 (普通分组 = 3)', -1, false],
  4: ['向后引用 (普通分组 = 4)', -1, false],
  5: ['向后引用 (普通分组 = 5)', -1, false],
  6: ['向后引用 (普通分组 = 6)', -1, false],
  7: ['向后引用 (普通分组 = 7)', -1, false],
  8: ['向后引用 (普通分组 = 8)', -1, false],
  9: ['向后引用 (普通分组 = 9)', -1, false],
  0: function() {
    if (this.arg) {
      return [`${String.fromCharCode(parseInt(this.arg, 8))}(octal: 0${this.arg.toUpperCase()})`,parseInt(this.arg, 8), false];
    } else {
      return ['null', 0, true];
    }
  },
  c() {
    return [`Ctrl + ${this.arg.toUpperCase()}`, this.arg.toUpperCase().charCodeAt(0) - 64, false];
  },
  x() {
    return [`${String.fromCharCode(parseInt(this.arg, 16))}(hex: 0x${this.arg.toUpperCase()})`,parseInt(this.arg, 16), false];
  },
  u() {
    var unicode = unescape("%u" + this.arg.replace(/\%u/g, "%u"));
    return [`${unicode}(unicode: U+${this.arg.toUpperCase()})`, parseInt(this.arg, 16), false];
  }
};