iterator

SlimIO Iterator utilities designed to manage and help developer to interact with iterators to release lazy code.

Requirements

• Node.js v12 or higher

Getting Started

This package is available in the Node Package Repository and can be easily installed with npm or yarn.

$ npm i @slimio/iterator
# or
$ yarn add @slimio/iterator

Usage example

const { fromStream, tryOn, whileOn, compose } = require("@slimio/iterator");
const { createReadStream } = require("fs");

function* splitLines(target) {
    let previous = "";
    try {
        while (true) {
            previous += yield;
            let eolIndex;
            while ((eolIndex = previous.indexOf("\n")) >= 0) {
                target.next(previous.slice(0, eolIndex));
                previous = previous.slice(eolIndex + 1);
            }
        }
    }
    finally {
        if (previous.length > 0) {
            target.next(previous);
        }
        target.return();
    }
}

function* numberLines(next) {
    for (let lineCount = 0; ;lineCount++) {
        next(`${lineCount}: ${yield}`);
    }
}

const fileToRead = process.argv[2];
fromStream(
    createReadStream(fileToRead), compose(splitLines, tryOn(numberLines), whileOn(console.log))
).then(() => console.log("done")).catch(console.error);

API

compose(...generatorFuncs: GeneratorFunction[]): Generator

tryOn(generatorFunc: GeneratorFunction): GeneratorFunction

whileOn(fn: Function): GeneratorFunction

fromStream(stream: Stream.Readable, target: Generator): Promise< void >

mergeAsyncIterator< T >(iterator: AsyncIterator< T >): T[];

Dependencies

Name	Refactoring	Security Risk	Usage
@slimio/is	Minor	Low	Type checker
is-stream	⚠️Major	Medium	Stream type checker

License

MIT