nano-pipe

A tiny library (<450 bytes gzipped) to create chainable functions/pipelines including support for async generators.

Installation

npm install nano-pipe

NanoPipe uses ES2016 and is not provided in transpiled form.

Version 9x of NodeJS requires the use of the --harmony flag.

You can use the code un-transpiled in the most recent versions of Chrome and Firefox. Edge requires transpiling.

Usage

NanoPipe can be used in three easy steps:

1. Use the static method NanoPipe.pipeable(function[,string]) to make functions chainable. You can pass in a regular function, an async function, a generator, or an async generator. If it is anonymous, you can pass in a string for the name. It will be called with each upstream value passed down the pipe bound to this. With the exception of undefined, values yielded or returned by your function are passed further down the pipeline.

function render(template) { // render a value into a string literal template
	return Function("return `" + template + "`").call(this);
}
function log() { // log a value to the console
	console.log(this);
	return this;
}
NanoPipe.pipeable(render);
NanoPipe.pipeable(log);

2. Create pipelines using your functions, e.g.

const mypipe1 = NanoPipe().render("Name: ${this.name}").log(),
	mypipe2 = NanoPipe().log();

3. Use the pipelines by feeding them iterables with <pipe>.pipe(iterable), including instantiated sychronous or asynchronous generators, as many times as you want, e.g.

mypipe1.pipe([{name:"Joe"},{name:"Mary"}]);

mypipe1.pipe([{name:"Jane"}]);

mypipe2.pipe([{name:"Joe"},{name:"Mary"}]);

mypipe2.pipe(async function*() { yield {name:"Joe"}; }());

pipe returns a Promise for an array of final values, so you can loop over them like this:

mypipe1.pipe([{name:"Joe"},{name:"Mary"}]).then(array => { for(const item of array) console.log(item); });

Examples

1. Load examples/index.html in your browser to see he above code in action.

2. Run node --harmony examples/scrape.js to see a web scraping pipeline.

API

Instance Methods

pipe(iterable) - The last call in a pipe chain invokes pipe processing and returns a Promise for an array of results based on the input iterable. All other methods are up to you!

Static Method For Custom Functions

NanoPipe.pipeable(function[,name]) - You can pass in any of the following function types to make the function available as part of a pipe:

1. function() {}

2. async function() {}

3. function*() {}

4. async function*() { }

Use name if your function is anonymous or you want to use a different name in the pipe.

pipeable is chainable so you can call NanoPipe.pipeable(f1).pipeable(f2)....

Release History (reverse chronological order)

2020-05-27 - v0.0.7 Adjusted to me more minimization robust by elimiating some compact destructures.

2018-04-30 - v0.0.6 Corrected README.md example typos.

2018-04-28 - v0.0.5 Updated scraping example.

2018-04-28 - v0.0.4 Made pipeable chainable. Added web scraping example.

2018-04-28 - v0.0.3 Added "use strict" and test script

2018-04-25 - v0.0.2 Added unit tests. Added support for multiple function types.

2018-04-25 - v0.0.1 First public release