vue hello world项目
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'use strict';
var getBuiltIn = require('../internals/get-built-in');
var uncurryThis = require('../internals/function-uncurry-this');
var aCallable = require('../internals/a-callable');
var lengthOfArrayLike = require('../internals/length-of-array-like');
var toObject = require('../internals/to-object');
var arraySpeciesCreate = require('../internals/array-species-create');
var Map = getBuiltIn('Map');
var MapPrototype = Map.prototype;
var mapForEach = uncurryThis(MapPrototype.forEach);
var mapHas = uncurryThis(MapPrototype.has);
var mapSet = uncurryThis(MapPrototype.set);
var push = uncurryThis([].push);
// `Array.prototype.uniqueBy` method
// https://github.com/tc39/proposal-array-unique
module.exports = function uniqueBy(resolver) {
var that = toObject(this);
var length = lengthOfArrayLike(that);
var result = arraySpeciesCreate(that, 0);
var map = new Map();
var resolverFunction = resolver != null ? aCallable(resolver) : function (value) {
return value;
};
var index, item, key;
for (index = 0; index < length; index++) {
item = that[index];
key = resolverFunction(item);
if (!mapHas(map, key)) mapSet(map, key, item);
}
mapForEach(map, function (value) {
push(result, value);
});
return result;
};