@walts81/linq-ts/lib/distinct.js

Typescript/Javascript LINQ implementation library

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.distinct = exports.distinctByKey = void 0;
Array.prototype.distinctByKey = distinctByKey;
Array.prototype.distinct = distinct;
function distinctByKey(expression = x => x) {
    const keys = [];
    return this.filter((x, i) => {
        const key = expression(x, i);
        const notExists = keys.indexOf(key) < 0;
        if (notExists)
            keys.push(key);
        return notExists;
    });
}
exports.distinctByKey = distinctByKey;
function distinct(compare) {
    const useCompare = !!compare;
    return this.filter((a, i, arr) => arr.indexOf(arr.first(b => (useCompare ? compare(a, b) : a === b))) === i);
}
exports.distinct = distinct;