You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
37 lines
1.2 KiB
37 lines
1.2 KiB
3 years ago
|
'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;
|
||
|
|
};
|