1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
/**
* The MIT License (MIT)
* Copyright (c) 2017-present Dmitry Soshnikov <dmitry.soshnikov@gmail.com>
*/
'use strict';
var NodePath = require('../../traverse/node-path');
var _require = require('../../transform/utils'),
disjunctionToList = _require.disjunctionToList,
listToDisjunction = _require.listToDisjunction;
/**
* Removes duplicates from a disjunction sequence:
*
* /(ab|bc|ab)+(xy|xy)+/ -> /(ab|bc)+(xy)+/
*/
module.exports = {
Disjunction: function Disjunction(path) {
var node = path.node;
// Make unique nodes.
var uniqueNodesMap = {};
var parts = disjunctionToList(node).filter(function (part) {
var encoded = part ? NodePath.getForNode(part).jsonEncode() : 'null';
// Already recorded this part, filter out.
if (uniqueNodesMap.hasOwnProperty(encoded)) {
return false;
}
uniqueNodesMap[encoded] = part;
return true;
});
// Replace with the optimized disjunction.
path.replace(listToDisjunction(parts));
}
};