https://github.com/luma-dev/deno-iterator-helpers

Strict and wrapper version implementation for https://github.com/tc39/proposal-iterator-helpers.
https://github.com/luma-dev/deno-iterator-helpers

deno iterator-helpers polyfill

Last synced: 21 days ago
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Strict and wrapper version implementation for https://github.com/tc39/proposal-iterator-helpers.

• Host: GitHub
• URL: https://github.com/luma-dev/deno-iterator-helpers
• Owner: luma-dev
• Created: 2021-09-10T03:21:50.000Z (about 3 years ago)
• Default Branch: main
• Last Pushed: 2021-12-15T01:16:52.000Z (almost 3 years ago)
• Last Synced: 2024-10-01T05:41:29.082Z (about 1 month ago)
• Topics: deno, iterator-helpers, polyfill
• Language: TypeScript
• Homepage:
• Size: 18.6 KB
• Stars: 5
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# deno-iterator-helpers

[![Codecov](https://img.shields.io/codecov/c/github/luma-dev/deno-iterator-helpers?style=flat-square)](https://app.codecov.io/gh/luma-dev/deno-iterator-helpers)

Strict and wrapper version implementation for

https://github.com/tc39/proposal-iterator-helpers.

## Usage

```ts

import {

  asyncIteratorFrom as fromA,

  iteratorFrom as from,

  wrapAsyncIterator as wrapA,

  wrapIterator as wrap,

} from "https://deno.land/x/iterator_helpers/mod.ts";

function* naturals() {

  let i = 0;

  while (true) {

    yield i;

    i += 1;

  }

}

const arr1 = wrap(naturals())

  .filter((n) => n % 2 === 1) // filter odd numbers

  .map((n) => n ** 2) // square numbers

  .flatMap((n) => [n, n]) // twice each numbers

  .take(10) // cut up to 10 items

  .toArray(); // evaluate and collect items into array

console.log(arr1); // [1, 1, 9, 9, 25, 25, 49, 49, 81, 81]

const arr2 = await wrapA(fromA(naturals()))

  .filter(async (n) => {

    const res = await fetch(`https://api.isevenapi.xyz/api/iseven/${n}/`);

    if (!res.body) throw new Error("No body");

    const raw = Uint8Array.from(

      await wrapA(fromA(res.body))

        .flatMap((e) => e)

        .toArray(),

    );

    const obj = JSON.parse(new TextDecoder().decode(raw));

    return obj.iseven;

  }) // filter even numbers

  .map((n) => n ** 2) // square numbers

  .flatMap((n) => [n, n]) // twice each numbers

  .take(10) // cut up to 10 items

  .toArray(); // evaluate and collect items into array

console.log(arr2); // [0, 0, 4, 4, 16, 16, 36, 36, 64, 64]

```

## Goals

- Implement all proposed features with wrapper API.

## Non-goals

- To make comprehensive library.

  - Just include defined features in the proposal.

- To extend global prototype.

  - Provide APIs via wrapper and method chaining.

## Iteration

- Until proposal becomes stage4, keeping it v0.x and up to date with bumping

  minor if there is breaking change.

- When interfaces are determined, bump major.

- When implemented natively, keep maintaining for months.

- After it passes some months, archive this project.

## Links

- https://github.com/tc39/proposal-iterator-helpers

- https://tc39.es/proposal-iterator-helpers