lilit
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JavaScript
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var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
return new (P || (P = Promise))(function (resolve, reject) {
function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
step((generator = generator.apply(thisArg, _arguments || [])).next());
});
};
var __await = (this && this.__await) || function (v) { return this instanceof __await ? (this.v = v, this) : new __await(v); }
var __asyncGenerator = (this && this.__asyncGenerator) || function (thisArg, _arguments, generator) {
if (!Symbol.asyncIterator) throw new TypeError("Symbol.asyncIterator is not defined.");
var g = generator.apply(thisArg, _arguments || []), i, q = [];
return i = {}, verb("next"), verb("throw"), verb("return"), i[Symbol.asyncIterator] = function () { return this; }, i;
function verb(n) { if (g[n]) i[n] = function (v) { return new Promise(function (a, b) { q.push([n, v, a, b]) > 1 || resume(n, v); }); }; }
function resume(n, v) { try { step(g[n](v)); } catch (e) { settle(q[0][3], e); } }
function step(r) { r.value instanceof __await ? Promise.resolve(r.value.v).then(fulfill, reject) : settle(q[0][2], r); }
function fulfill(value) { resume("next", value); }
function reject(value) { resume("throw", value); }
function settle(f, v) { if (f(v), q.shift(), q.length) resume(q[0][0], q[0][1]); }
};
Object.defineProperty(exports, "__esModule", { value: true });
function iterator(xs) {
const it = xs[Symbol.iterator]();
if (!it[Symbol.iterator])
it[Symbol.iterator] = () => it;
return it;
}
exports.iterator = iterator;
function asyncIterator(xs) {
const it = xs[Symbol.asyncIterator]();
if (!it[Symbol.asyncIterator])
it[Symbol.asyncIterator] = () => it;
return it;
}
exports.asyncIterator = asyncIterator;
function forAwaitableIterator(xs) {
return xs[Symbol.asyncIterator] ? asyncIterator(xs) : iterator(xs);
}
exports.forAwaitableIterator = forAwaitableIterator;
function isIterator(xs) {
return xs && xs[Symbol.iterator] && xs[Symbol.iterator]() === xs;
}
exports.isIterator = isIterator;
function isAsyncIterator(xs) {
return xs && xs[Symbol.asyncIterator] && xs[Symbol.asyncIterator]() === xs;
}
exports.isAsyncIterator = isAsyncIterator;
function isForOfAwaitableIterator(xs) {
return isAsyncIterator(xs) || isIterator(xs);
}
exports.isForOfAwaitableIterator = isForOfAwaitableIterator;
// https://stackoverflow.com/a/46416353/870615
function tee(it) {
// If `it` is not an iterator, i.e. can be traversed more than once,
// we just return it unmodified.
if (!isIterator(it))
return [it, it];
const source = it;
const buffers = [[], []];
const DONE = Symbol('done');
const next = (i) => {
if (buffers[i].length)
return buffers[i].shift();
const x = source.next();
if (x.done)
return DONE;
buffers[1 - i].push(x.value);
return x.value;
};
function* buffer2Iterable(i) {
while (true) {
const x = next(i);
if (x === DONE)
break;
yield x;
}
}
return [buffer2Iterable(0), buffer2Iterable(1)];
}
exports.tee = tee;
function asyncTee(it) {
if (!isForOfAwaitableIterator(it))
return [it, it];
const source = it;
const buffers = [[], []];
const DONE = Symbol('done');
const next = (i) => __awaiter(this, void 0, void 0, function* () {
if (buffers[i].length)
return buffers[i].shift();
const x = yield source.next();
if (x.done)
return DONE;
buffers[1 - i].push(x.value);
return x.value;
});
function buffer2AsyncIterable(i) {
return __asyncGenerator(this, arguments, function* buffer2AsyncIterable_1() {
while (true) {
const x = yield __await(next(i));
if (x === DONE)
break;
yield yield __await(x);
}
});
}
return [buffer2AsyncIterable(0), buffer2AsyncIterable(1)];
}
exports.asyncTee = asyncTee;
// TODO: more performant impl?
function teeN(it, n = 2) {
const res = [];
let orig = it;
let copy;
for (let i = 0; i < n - 1; i++) {
[orig, copy] = tee(orig);
res.push(copy);
}
res.push(orig);
return res;
}
exports.teeN = teeN;
function asyncTeeN(it, n = 2) {
const res = [];
let orig = it;
let copy;
for (let i = 0; i < n - 1; i++) {
[orig, copy] = asyncTee(orig);
res.push(copy);
}
res.push(orig);
return res;
}
exports.asyncTeeN = asyncTeeN;
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