Function generateMatcher

esquery.js:117–348

* Create a matcher function for `selector`, * @param {?SelectorAST} selector * @returns {SelectorMatcher}

(selector)

 * @returns {SelectorMatcher}
 */
function generateMatcher(selector) {
    switch(selector.type) {
        case 'wildcard':
            return () => true;

        case 'identifier': {
            const value = selector.value.toLowerCase();
            return (node, ancestry, options) => {
                const nodeTypeKey = (options && options.nodeTypeKey) || 'type';
                return value === node[nodeTypeKey].toLowerCase();
            };
        }

        case 'exactNode':
            return (node, ancestry) => {
                return ancestry.length === 0;
            };

        case 'field': {
            const path = selector.name.split('.');
            return (node, ancestry) => {
                const ancestor = ancestry[path.length - 1];
                return inPath(node, ancestor, path, 0);
            };
        }

        case 'matches': {
            const matchers = selector.selectors.map(getMatcher);
            return (node, ancestry, options) => {
                for (let i = 0; i < matchers.length; ++i) {
                    if (matchers[i](node, ancestry, options)) { return true; }
                }
                return false;
            };
        }

        case 'compound': {
            const matchers = selector.selectors.map(getMatcher);
            return (node, ancestry, options) => {
                for (let i = 0; i < matchers.length; ++i) {
                    if (!matchers[i](node, ancestry, options)) { return false; }
                }
                return true;
            };
        }

        case 'not': {
            const matchers = selector.selectors.map(getMatcher);
            return (node, ancestry, options) => {
                for (let i = 0; i < matchers.length; ++i) {
                    if (matchers[i](node, ancestry, options)) { return false; }
                }
                return true;
            };
        }

        case 'has': {
            const matchers = selector.selectors.map(getMatcher);