d2-ui
Version:
108 lines (99 loc) • 3.17 kB
JavaScript
/**
* lodash (Custom Build) <https://lodash.com/>
* Build: `lodash modularize exports="npm" -o ./`
* Copyright jQuery Foundation and other contributors <https://jquery.org/>
* Released under MIT license <https://lodash.com/license>
* Based on Underscore.js 1.8.3 <http://underscorejs.org/LICENSE>
* Copyright Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
*/
var baseIteratee = require('lodash._baseiteratee'),
rest = require('lodash.rest');
/** Used as the `TypeError` message for "Functions" methods. */
var FUNC_ERROR_TEXT = 'Expected a function';
/**
* A faster alternative to `Function#apply`, this function invokes `func`
* with the `this` binding of `thisArg` and the arguments of `args`.
*
* @private
* @param {Function} func The function to invoke.
* @param {*} thisArg The `this` binding of `func`.
* @param {Array} args The arguments to invoke `func` with.
* @returns {*} Returns the result of `func`.
*/
function apply(func, thisArg, args) {
var length = args.length;
switch (length) {
case 0: return func.call(thisArg);
case 1: return func.call(thisArg, args[0]);
case 2: return func.call(thisArg, args[0], args[1]);
case 3: return func.call(thisArg, args[0], args[1], args[2]);
}
return func.apply(thisArg, args);
}
/**
* A specialized version of `_.map` for arrays without support for iteratee
* shorthands.
*
* @private
* @param {Array} array The array to iterate over.
* @param {Function} iteratee The function invoked per iteration.
* @returns {Array} Returns the new mapped array.
*/
function arrayMap(array, iteratee) {
var index = -1,
length = array.length,
result = Array(length);
while (++index < length) {
result[index] = iteratee(array[index], index, array);
}
return result;
}
/**
* Creates a function that iterates over `pairs` and invokes the corresponding
* function of the first predicate to return truthy. The predicate-function
* pairs are invoked with the `this` binding and arguments of the created
* function.
*
* @static
* @memberOf _
* @since 4.0.0
* @category Util
* @param {Array} pairs The predicate-function pairs.
* @returns {Function} Returns the new composite function.
* @example
*
* var func = _.cond([
* [_.matches({ 'a': 1 }), _.constant('matches A')],
* [_.conforms({ 'b': _.isNumber }), _.constant('matches B')],
* [_.constant(true), _.constant('no match')]
* ]);
*
* func({ 'a': 1, 'b': 2 });
* // => 'matches A'
*
* func({ 'a': 0, 'b': 1 });
* // => 'matches B'
*
* func({ 'a': '1', 'b': '2' });
* // => 'no match'
*/
function cond(pairs) {
var length = pairs ? pairs.length : 0,
toIteratee = baseIteratee;
pairs = !length ? [] : arrayMap(pairs, function(pair) {
if (typeof pair[1] != 'function') {
throw new TypeError(FUNC_ERROR_TEXT);
}
return [toIteratee(pair[0]), pair[1]];
});
return rest(function(args) {
var index = -1;
while (++index < length) {
var pair = pairs[index];
if (apply(pair[0], this, args)) {
return apply(pair[1], this, args);
}
}
});
}
module.exports = cond;