@beenotung/tslib/lazy/lazy-list.js

utils library in Typescript

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.LazyList = void 0;
const lazy_1 = require("./lazy");
/**
 * @description lazy linked list
 * */
class LazyList extends lazy_1.Lazy {
    isHead;
    tail;
    mapper;
    constructor(value, tail, mapper) {
        super(value || (() => undefined));
        if (arguments.length === 0) {
            this.isHead = true;
        }
        this.tail = tail;
        this.mapper = mapper;
    }
    append(a) {
        return new LazyList(a, this, this.mapper);
    }
    appendRaw(a) {
        return this.append(() => a);
    }
    appendAll(xs) {
        return xs.reduce((acc, c) => acc.appendRaw(c), this);
    }
    /** @description non-lazy */
    toArray(thisArg = this) {
        const xs = [];
        for (let c = thisArg; c && !c.isHead; c = c.tail) {
            if (c.mapper) {
                xs.push(c.mapper(c.value()));
            }
            else {
                xs.push(c.value());
            }
        }
        return xs;
    }
    /** @override */
    map(f) {
        if (this.mapper) {
            const mapper = this.mapper;
            return new LazyList(() => this.value(), this.tail, a => f(mapper(a)));
        }
        else {
            return new LazyList(() => this.value(), this.tail, f);
        }
    }
}
exports.LazyList = LazyList;
(function (LazyList) {
    LazyList.headSymbol = Symbol.for('head');
    LazyList.empty = () => new LazyList();
    LazyList.fromArray = (xs) => LazyList.empty().appendAll(xs);
})(LazyList || (exports.LazyList = LazyList = {}));