35 lines
743 B
JavaScript
35 lines
743 B
JavaScript
/**
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* The MIT License (MIT)
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* Copyright (c) 2017-present Dmitry Soshnikov <dmitry.soshnikov@gmail.com>
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*/
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'use strict';
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/**
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* A regexp-tree plugin to replace `a+` to `aa*`, since NFA/DFA
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* handles Kleene-closure `a*`, and `a+` is just a syntactic sugar.
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*/
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module.exports = {
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Repetition: function Repetition(path) {
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var node = path.node,
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parent = path.parent;
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if (node.quantifier.kind !== '+') {
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return;
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}
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if (parent.type === 'Alternative') {
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path.getParent().insertChildAt(node.expression, path.index);
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} else {
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path.replace({
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type: 'Alternative',
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expressions: [node.expression, node]
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});
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}
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// Change quantifier.
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node.quantifier.kind = '*';
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}
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}; |