140 lines
4.6 KiB
JavaScript
140 lines
4.6 KiB
JavaScript
(function (global, factory) {
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if (typeof define === "function" && define.amd) {
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define('Reselect', ['exports'], factory);
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} else if (typeof exports !== "undefined") {
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factory(exports);
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} else {
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var mod = {
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exports: {}
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};
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factory(mod.exports);
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global.Reselect = mod.exports;
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}
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})(this, function (exports) {
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'use strict';
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exports.__esModule = true;
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exports.defaultMemoize = defaultMemoize;
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exports.createSelectorCreator = createSelectorCreator;
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exports.createStructuredSelector = createStructuredSelector;
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function defaultEqualityCheck(a, b) {
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return a === b;
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}
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function areArgumentsShallowlyEqual(equalityCheck, prev, next) {
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if (prev === null || next === null || prev.length !== next.length) {
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return false;
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}
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// Do this in a for loop (and not a `forEach` or an `every`) so we can determine equality as fast as possible.
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var length = prev.length;
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for (var i = 0; i < length; i++) {
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if (!equalityCheck(prev[i], next[i])) {
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return false;
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}
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}
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return true;
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}
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function defaultMemoize(func) {
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var equalityCheck = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : defaultEqualityCheck;
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var lastArgs = null;
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var lastResult = null;
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// we reference arguments instead of spreading them for performance reasons
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return function () {
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if (!areArgumentsShallowlyEqual(equalityCheck, lastArgs, arguments)) {
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// apply arguments instead of spreading for performance.
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lastResult = func.apply(null, arguments);
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}
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lastArgs = arguments;
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return lastResult;
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};
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}
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function getDependencies(funcs) {
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var dependencies = Array.isArray(funcs[0]) ? funcs[0] : funcs;
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if (!dependencies.every(function (dep) {
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return typeof dep === 'function';
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})) {
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var dependencyTypes = dependencies.map(function (dep) {
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return typeof dep;
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}).join(', ');
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throw new Error('Selector creators expect all input-selectors to be functions, ' + ('instead received the following types: [' + dependencyTypes + ']'));
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}
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return dependencies;
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}
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function createSelectorCreator(memoize) {
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for (var _len = arguments.length, memoizeOptions = Array(_len > 1 ? _len - 1 : 0), _key = 1; _key < _len; _key++) {
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memoizeOptions[_key - 1] = arguments[_key];
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}
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return function () {
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for (var _len2 = arguments.length, funcs = Array(_len2), _key2 = 0; _key2 < _len2; _key2++) {
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funcs[_key2] = arguments[_key2];
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}
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var recomputations = 0;
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var resultFunc = funcs.pop();
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var dependencies = getDependencies(funcs);
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var memoizedResultFunc = memoize.apply(undefined, [function () {
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recomputations++;
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// apply arguments instead of spreading for performance.
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return resultFunc.apply(null, arguments);
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}].concat(memoizeOptions));
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// If a selector is called with the exact same arguments we don't need to traverse our dependencies again.
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var selector = defaultMemoize(function () {
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var params = [];
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var length = dependencies.length;
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for (var i = 0; i < length; i++) {
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// apply arguments instead of spreading and mutate a local list of params for performance.
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params.push(dependencies[i].apply(null, arguments));
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}
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// apply arguments instead of spreading for performance.
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return memoizedResultFunc.apply(null, params);
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});
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selector.resultFunc = resultFunc;
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selector.recomputations = function () {
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return recomputations;
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};
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selector.resetRecomputations = function () {
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return recomputations = 0;
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};
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return selector;
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};
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}
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var createSelector = exports.createSelector = createSelectorCreator(defaultMemoize);
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function createStructuredSelector(selectors) {
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var selectorCreator = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : createSelector;
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if (typeof selectors !== 'object') {
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throw new Error('createStructuredSelector expects first argument to be an object ' + ('where each property is a selector, instead received a ' + typeof selectors));
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}
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var objectKeys = Object.keys(selectors);
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return selectorCreator(objectKeys.map(function (key) {
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return selectors[key];
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}), function () {
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for (var _len3 = arguments.length, values = Array(_len3), _key3 = 0; _key3 < _len3; _key3++) {
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values[_key3] = arguments[_key3];
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}
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return values.reduce(function (composition, value, index) {
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composition[objectKeys[index]] = value;
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return composition;
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}, {});
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});
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}
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});
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