/*---------------------------------------------------------------------------------------------
 *  Copyright (c) Microsoft Corporation. All rights reserved.
 *  Licensed under the MIT License. See License.txt in the project root for license information.
 *--------------------------------------------------------------------------------------------*/
define(["require", "exports"], function (require, exports) {
    "use strict";
    Object.defineProperty(exports, "__esModule", { value: true });
    exports.Iterable = void 0;
    var Iterable;
    (function (Iterable) {
        function is(thing) {
            return thing && typeof thing === 'object' && typeof thing[Symbol.iterator] === 'function';
        }
        Iterable.is = is;
        const _empty = Object.freeze([]);
        function empty() {
            return _empty;
        }
        Iterable.empty = empty;
        function* single(element) {
            yield element;
        }
        Iterable.single = single;
        function from(iterable) {
            return iterable || _empty;
        }
        Iterable.from = from;
        function first(iterable) {
            return iterable[Symbol.iterator]().next().value;
        }
        Iterable.first = first;
        function some(iterable, predicate) {
            for (const element of iterable) {
                if (predicate(element)) {
                    return true;
                }
            }
            return false;
        }
        Iterable.some = some;
        function* filter(iterable, predicate) {
            for (const element of iterable) {
                if (predicate(element)) {
                    yield element;
                }
            }
        }
        Iterable.filter = filter;
        function* map(iterable, fn) {
            for (const element of iterable) {
                yield fn(element);
            }
        }
        Iterable.map = map;
        function* concat(...iterables) {
            for (const iterable of iterables) {
                for (const element of iterable) {
                    yield element;
                }
            }
        }
        Iterable.concat = concat;
        /**
         * Consumes `atMost` elements from iterable and returns the consumed elements,
         * and an iterable for the rest of the elements.
         */
        function consume(iterable, atMost = Number.POSITIVE_INFINITY) {
            const consumed = [];
            if (atMost === 0) {
                return [consumed, iterable];
            }
            const iterator = iterable[Symbol.iterator]();
            for (let i = 0; i < atMost; i++) {
                const next = iterator.next();
                if (next.done) {
                    return [consumed, Iterable.empty()];
                }
                consumed.push(next.value);
            }
            return [consumed, { [Symbol.iterator]() { return iterator; } }];
        }
        Iterable.consume = consume;
    })(Iterable = exports.Iterable || (exports.Iterable = {}));
});
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