subexp.js

subexp.js
¶

Subexp nodes are for expressions inside of parenthesis. It is rendered as a labeled box around the contained expression if a label is required.
```
import _ from 'lodash';

export default {
  type: 'subexp',

  definedProperties: {
```

Default anchor is overridden to move it down to account for the group label and outline box.

    _anchor: {
      get: function() {
        var anchor = this.regexp.getBBox(),
            matrix = this.transform().localMatrix;

        return {
          ax: matrix.x(anchor.ax, anchor.ay),
          ax2: matrix.x(anchor.ax2, anchor.ay),
          ay: matrix.y(anchor.ax, anchor.ay)
        };
      }
    }
  },

  labelMap: {
    '?:': '',
    '?=': '正向前瞻',
    '?!': '负向前瞻'
  },

¶

Renders the subexp into the currently set container.
```
  _render() {
```
¶

NOTE: this.label() MUST be called here, in _render, and before any child nodes are rendered. This is to keep the group numbers in the correct order.
```
    let label = this.label();
```

Render the contained regexp.

    return this.regexp.render(this.container.group())

Create the labeled box around the regexp.

      .then(() => this.renderLabeledBox(label, this.regexp, {
        padding: 10
      }));
  },

Returns the label for the subexpression.

  label() {
    if (_.has(this.labelMap, this.properties.capture.textValue)) {
      return this.labelMap[this.properties.capture.textValue];
    } else {
      return `普通捕获分组 #${this.state.groupCounter++}`;
    }
  },

  setup() {

¶

NOTE: DO NOT call this.label() in setup. It will lead to groups being numbered in reverse order.
```
    this.regexp = this.properties.regexp;
```

If there is no need for a label, then proxy to the nested regexp.

    if (this.properties.capture.textValue == '?:') {
      this.proxy = this.regexp;
    }
  }
};