setup-php/node_modules/regexp-tree/dist/optimizer/transforms/remove-empty-group-transform.js
2019-09-20 21:54:46 +05:30

34 lines
599 B
JavaScript

/**
* The MIT License (MIT)
* Copyright (c) 2017-present Dmitry Soshnikov <dmitry.soshnikov@gmail.com>
*/
'use strict';
/**
* A regexp-tree plugin to remove non-capturing empty groups.
*
* /(?:)a/ -> /a/
* /a|(?:)/ -> /a|/
*/
module.exports = {
Group: function Group(path) {
var node = path.node,
parent = path.parent;
var childPath = path.getChild();
if (node.capturing || childPath) {
return;
}
if (parent.type === 'Repetition') {
path.getParent().replace(node);
} else if (parent.type !== 'RegExp') {
path.remove();
}
}
};