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// Copyright 2023-latest Tomoki Miyauchi. All rights reserved. MIT license.// This module is browser compatible.
// TODO(miyauci): Use [Iterator Helpers](https://github.com/tc39/proposal-iterator-helpers) if supported.
import { isPositiveNumber } from "./deps.ts";
/** * Returns an iterator that computes the given mapper function using arguments * from each of the iterables. */export function* map<T, V>(  iterable: Readonly<Iterable<T>>,  mapper: (item: T) => V,): Iterable<V> {  for (const value of iterable) {    yield mapper(value);  }}
/** Returns an iterator object for the given iterable. */export function iter<T>(iterable: Readonly<Iterable<T>>): Iterator<T> {  return iterable[Symbol.iterator]();}
/** Create iterable iterable. */export function iterIter<T>(  iterable: Readonly<Iterable<T>>,): IterableIterator<T> {  const iterator = iter(iterable);
  return {    [Symbol.iterator]() {      return this;    },    next() {      return iterator.next();    },  };}
/** Take element from iterable. * * @throws {RangeError} If the {@link limit} is not positive integer. */export function* take<T>(  iterable: Readonly<Iterable<T>>,  limit = Number.MAX_SAFE_INTEGER,): Iterable<T> {  if (!isPositiveInteger(limit)) {    throw new RangeError("limit must be an positive integer");  }
  for (const [i, value] of enumerate(iterable)) {    yield value;
    if (limit <= i + 1) break;  }}
/** Entries for iterable. */export function* enumerate<T>(  iterable: Readonly<Iterable<T>>,  start = 0,): Iterable<[index: number, item: T]> {  for (const item of iterable) {    yield [start++, item];  }}
/** Return item count. */export function count(input: Readonly<Iterable<unknown>>): number {  return [...input].length;}
/** Whether the input is positive integer or not. */export function isPositiveInteger(input: number): boolean {  return Number.isInteger(input) && isPositiveNumber(input);}