@async-generators/filter
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    0.1.1 • Public • Published

    filter

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    filter an iterable sequence

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    Usage

    package requires a system that supports async-iteration, either natively or via down-compiling

    Install

    npm install @async-generators/filter --save
    yarn add @async-generators/filter
    

    This package's main entry points to a commonjs distribution.

    Additionally, the module entry points to a es2015 distribution, which can be used by build systems, such as webpack, to directly use es2015 modules.

    Api

    filter(source, predicate)

    filter() iterates the source and yields any item where await predicate(item) === true

    source must have a [Symbol.asyncIterator] or [Symbol.iterator] property. If both are present only [Symbol.asyncIterator] is used.

    predicate(item, index) should return a boolean (optionally as Promise) to signal whether the item should be yielded. The second parameter is the index of the item as it appears in the source sequence.

    Example

    example.js

    const filter = require('@async-generators/filter').default;
    
    async function* source() {
      yield 1; yield 2; yield 3; yield 4;
    }
    
    async function main(){
      for await (let item of filter(source(), x=>x > 1 && x < 4)){
         console.log(item);
      }
    }
    
    main();

    Execute with the latest node.js:

    node --harmony-async-iteration example.js
    

    output:

    2
    3
    

    Typescript

    This library is fully typed and can be imported using:

    import filter from '@async-generators/filter');

    It is also possible to directly execute your properly configured typescript with ts-node:

    ts-node --harmony_async_iteration foo.ts
    

    Install

    npm i @async-generators/filter

    DownloadsWeekly Downloads

    75

    Version

    0.1.1

    License

    MIT

    Last publish

    Collaborators

    • meirionhughes