pied-piper

Stream and pipeline utilities for your node.js project.

Install

$ npm install --save pied-piper

Examples

var stream = require('pied-piper');

//
// Pipeline Style
//
stream(
  process.stdin,
  stream.split(),
  stream.prepend('-> '),
  stream.append(' <-\n'),
  process.stdout
);

//
// Chaining Style
//
stream()
  .stdin()
  .split()
  .filter(function(chunk) { return chunk && chunk != '' })
  .prepend('-> ')
  .append(' <-\n')
  .stdout();

//  
// Stream Style
//
process.stdin
  .pipe(stream.split())
  .pipe(stream.filter(function(chunk) { return chunk && chunk != '' }))
  .pipe(stream.prepend('-> '))
  .pipe(stream.append(' <-\n'))
  .pipe(process.stdout);

//
// Mix 'n' Match Style
//
var getLines = stream()
  .split()
  .filter(function(chunk) { return chunk && chunk != '' })
  .toStream();

var makePretty = stream(
  stream.prepend(' -> '),
  stream.append(' <-\n')
);

process.stdin
  .pipe(getLines)
  .pipe(makePretty)
  .pipe(stream.stdout);

Quick & Dirty API Reference

  //
  // Creates a new stream/pipeline.
  //
  // Streams passed as arguments will be piped together in order.
  // If no stream is provided it will create a through stream.
  //
  // The streams can be of any type so long as it makes sense to
  // pipe them together.
  //
  // Eg: All but the last argument need to be readable and all but
  // the first argument need to be writable.
  //
  var through   = stream();
  var pipeline  = stream(readable, transform, transform, writable);
  var transform = stream(transform, transform, transform);

  // If your first stream is writable then you can pipe to it:
  process.stdin.pipe(transform.toStream())

  // If the last stream is readable then you can pipe from it:
  transform.pipe(process.stdout);

  // Input Streams
  stream.readFile(filename);
  stream.readObject(object);
  stream.readArray(array);
  stream.stdin();

  // Output Streams
  stream.writeFile(filename);
  stream.stdout();
  stream.stderr();
  stream.collect(function(array) {});

  // Transform Streams
  stream()
    .append('string')
    .each(function(chunk) { })
    .filter(function(chunk) { return true; })
    .invoke('method', arg1, arg2, etc)
    .join('\n')
    .limit(5)
    .map(function(chunk) { return chunk; })
    .prepend('string')
    .replace('teh', 'the')
    .skip(10)
    .split('\n')
    .toJSON()
    .toLowerCase()
    .toString()
    .toUpperCase()
    .createHash('md5');

  // Or
  stream.append('string');
  stream.skip(10);
  // etc

  // Consumer functions
  // When used statically the first argument is the Stream to be consumed
  stream()
    .count(function(resultObject) { });

  // Or
  stream.count(process.stdin, function(resultObject) { });

Licence

The MIT License (MIT)

Copyright (c) 2014 James Wyse james@jameswyse.net

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.