320 lines
13 KiB
JavaScript
320 lines
13 KiB
JavaScript
/* vim: set sw=4 sts=4 : */
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(function () {
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var estraverse = require('estraverse');
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var parser = require('./parser');
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var isArray = Array.isArray || function isArray(array) {
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return {}.toString.call(array) === '[object Array]';
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};
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var LEFT_SIDE = {};
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var RIGHT_SIDE = {};
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function esqueryModule() {
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/**
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* Get the value of a property which may be multiple levels down in the object.
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*/
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function getPath(obj, key) {
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var i, keys = key.split(".");
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for (i = 0; i < keys.length; i++) {
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if (obj == null) { return obj; }
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obj = obj[keys[i]];
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}
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return obj;
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}
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/**
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* Determine whether `node` can be reached by following `path`, starting at `ancestor`.
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*/
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function inPath(node, ancestor, path) {
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var field, remainingPath, i;
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if (path.length === 0) { return node === ancestor; }
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if (ancestor == null) { return false; }
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field = ancestor[path[0]];
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remainingPath = path.slice(1);
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if (isArray(field)) {
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for (i = 0, l = field.length; i < l; ++i) {
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if (inPath(node, field[i], remainingPath)) { return true; }
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}
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return false;
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} else {
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return inPath(node, field, remainingPath);
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}
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}
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/**
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* Given a `node` and its ancestors, determine if `node` is matched by `selector`.
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*/
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function matches(node, selector, ancestry) {
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var path, ancestor, i, l, p;
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if (!selector) { return true; }
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if (!node) { return false; }
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if (!ancestry) { ancestry = []; }
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switch(selector.type) {
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case 'wildcard':
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return true;
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case 'identifier':
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return selector.value.toLowerCase() === node.type.toLowerCase();
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case 'field':
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path = selector.name.split('.');
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ancestor = ancestry[path.length - 1];
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return inPath(node, ancestor, path);
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case 'matches':
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for (i = 0, l = selector.selectors.length; i < l; ++i) {
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if (matches(node, selector.selectors[i], ancestry)) { return true; }
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}
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return false;
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case 'compound':
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for (i = 0, l = selector.selectors.length; i < l; ++i) {
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if (!matches(node, selector.selectors[i], ancestry)) { return false; }
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}
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return true;
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case 'not':
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for (i = 0, l = selector.selectors.length; i < l; ++i) {
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if (matches(node, selector.selectors[i], ancestry)) { return false; }
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}
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return true;
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case 'child':
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if (matches(node, selector.right, ancestry)) {
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return matches(ancestry[0], selector.left, ancestry.slice(1));
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}
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return false;
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case 'descendant':
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if (matches(node, selector.right, ancestry)) {
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for (i = 0, l = ancestry.length; i < l; ++i) {
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if (matches(ancestry[i], selector.left, ancestry.slice(i + 1))) {
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return true;
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}
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}
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}
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return false;
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case 'attribute':
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p = getPath(node, selector.name);
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switch (selector.operator) {
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case null:
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case void 0:
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return p != null;
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case '=':
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switch (selector.value.type) {
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case 'regexp': return selector.value.value.test(p);
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case 'literal': return '' + selector.value.value === '' + p;
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case 'type': return selector.value.value === typeof p;
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}
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case '!=':
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switch (selector.value.type) {
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case 'regexp': return !selector.value.value.test(p);
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case 'literal': return '' + selector.value.value !== '' + p;
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case 'type': return selector.value.value !== typeof p;
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}
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case '<=': return p <= selector.value.value;
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case '<': return p < selector.value.value;
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case '>': return p > selector.value.value;
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case '>=': return p >= selector.value.value;
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}
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case 'sibling':
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return matches(node, selector.right, ancestry) &&
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sibling(node, selector.left, ancestry, LEFT_SIDE) ||
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selector.left.subject &&
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matches(node, selector.left, ancestry) &&
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sibling(node, selector.right, ancestry, RIGHT_SIDE);
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case 'adjacent':
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return matches(node, selector.right, ancestry) &&
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adjacent(node, selector.left, ancestry, LEFT_SIDE) ||
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selector.right.subject &&
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matches(node, selector.left, ancestry) &&
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adjacent(node, selector.right, ancestry, RIGHT_SIDE);
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case 'nth-child':
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return matches(node, selector.right, ancestry) &&
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nthChild(node, ancestry, function (length) {
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return selector.index.value - 1;
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});
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case 'nth-last-child':
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return matches(node, selector.right, ancestry) &&
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nthChild(node, ancestry, function (length) {
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return length - selector.index.value;
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});
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case 'class':
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if(!node.type) return false;
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switch(selector.name.toLowerCase()){
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case 'statement':
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if(node.type.slice(-9) === 'Statement') return true;
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// fallthrough: interface Declaration <: Statement { }
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case 'declaration':
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return node.type.slice(-11) === 'Declaration';
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case 'pattern':
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if(node.type.slice(-7) === 'Pattern') return true;
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// fallthrough: interface Expression <: Node, Pattern { }
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case 'expression':
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return node.type.slice(-10) === 'Expression' ||
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node.type === 'Literal' ||
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node.type === 'Identifier';
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case 'function':
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return node.type.slice(0, 8) === 'Function' ||
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node.type === 'ArrowFunctionExpression';
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}
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throw new Error('Unknown class name: ' + selector.name);
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}
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throw new Error('Unknown selector type: ' + selector.type);
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}
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/*
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* Determines if the given node has a sibling that matches the given selector.
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*/
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function sibling(node, selector, ancestry, side) {
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var parent = ancestry[0], listProp, startIndex, keys, i, l, k, lowerBound, upperBound;
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if (!parent) { return false; }
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keys = estraverse.VisitorKeys[parent.type];
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for (i = 0, l = keys.length; i < l; ++i) {
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listProp = parent[keys[i]];
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if (isArray(listProp)) {
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startIndex = listProp.indexOf(node);
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if (startIndex < 0) { continue; }
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if (side === LEFT_SIDE) {
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lowerBound = 0;
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upperBound = startIndex;
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} else {
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lowerBound = startIndex + 1;
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upperBound = listProp.length;
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}
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for (k = lowerBound; k < upperBound; ++k) {
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if (matches(listProp[k], selector, ancestry)) {
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return true;
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}
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}
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}
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}
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return false;
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}
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/*
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* Determines if the given node has an asjacent sibling that matches the given selector.
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*/
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function adjacent(node, selector, ancestry, side) {
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var parent = ancestry[0], listProp, keys, i, l, idx;
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if (!parent) { return false; }
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keys = estraverse.VisitorKeys[parent.type];
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for (i = 0, l = keys.length; i < l; ++i) {
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listProp = parent[keys[i]];
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if (isArray(listProp)) {
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idx = listProp.indexOf(node);
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if (idx < 0) { continue; }
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if (side === LEFT_SIDE && idx > 0 && matches(listProp[idx - 1], selector, ancestry)) {
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return true;
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}
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if (side === RIGHT_SIDE && idx < listProp.length - 1 && matches(listProp[idx + 1], selector, ancestry)) {
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return true;
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}
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}
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}
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return false;
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}
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/*
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* Determines if the given node is the nth child, determined by idxFn, which is given the containing list's length.
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*/
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function nthChild(node, ancestry, idxFn) {
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var parent = ancestry[0], listProp, keys, i, l, idx;
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if (!parent) { return false; }
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keys = estraverse.VisitorKeys[parent.type];
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for (i = 0, l = keys.length; i < l; ++i) {
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listProp = parent[keys[i]];
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if (isArray(listProp)) {
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idx = listProp.indexOf(node);
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if (idx >= 0 && idx === idxFn(listProp.length)) { return true; }
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}
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}
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return false;
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}
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/*
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* For each selector node marked as a subject, find the portion of the selector that the subject must match.
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*/
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function subjects(selector, ancestor) {
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var results, p;
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if (selector == null || typeof selector != 'object') { return []; }
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if (ancestor == null) { ancestor = selector; }
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results = selector.subject ? [ancestor] : [];
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for(p in selector) {
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if(!{}.hasOwnProperty.call(selector, p)) { continue; }
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[].push.apply(results, subjects(selector[p], p === 'left' ? selector[p] : ancestor));
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}
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return results;
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}
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/**
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* From a JS AST and a selector AST, collect all JS AST nodes that match the selector.
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*/
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function match(ast, selector) {
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var ancestry = [], results = [], altSubjects, i, l, k, m;
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if (!selector) { return results; }
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altSubjects = subjects(selector);
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estraverse.traverse(ast, {
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enter: function (node, parent) {
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if (parent != null) { ancestry.unshift(parent); }
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if (matches(node, selector, ancestry)) {
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if (altSubjects.length) {
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for (i = 0, l = altSubjects.length; i < l; ++i) {
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if (matches(node, altSubjects[i], ancestry)) { results.push(node); }
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for (k = 0, m = ancestry.length; k < m; ++k) {
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if (matches(ancestry[k], altSubjects[i], ancestry.slice(k + 1))) {
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results.push(ancestry[k]);
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}
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}
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}
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} else {
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results.push(node);
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}
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}
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},
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leave: function () { ancestry.shift(); }
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});
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return results;
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}
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/**
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* Parse a selector string and return its AST.
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*/
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function parse(selector) {
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return parser.parse(selector);
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}
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/**
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* Query the code AST using the selector string.
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*/
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function query(ast, selector) {
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return match(ast, parse(selector));
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}
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query.parse = parse;
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query.match = match;
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query.matches = matches;
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return query.query = query;
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}
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if (typeof define === "function" && define.amd) {
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define(esqueryModule);
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} else if (typeof module !== 'undefined' && module.exports) {
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module.exports = esqueryModule();
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} else {
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this.esquery = esqueryModule();
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}
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})();
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