GoScrobble/web/node_modules/reselect/dist/reselect.js

141 lines
4.6 KiB
JavaScript

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