from2 

from2 is a high-level module for creating readable streams that properly handle backpressure.
Convience wrapper for
readable-stream's ReadableStream
base class, with an API lifted from
from and
through2.
Usage
stream = from2([opts], read)
Where opts are the options to pass on to the ReadableStream constructor,
and read(size, next) is called when data is requested from the stream.
- sizeis the recommended amount of data (in bytes) to retrieve.
- next(err)should be called when you're ready to emit more data.
For example, here's a readable stream that emits the contents of a given string:
var from = require('from2')
function fromString(string) {
  return from(function(size, next) {
    // if there's no more content
    // left in the string, close the stream.
    if (string.length <= 0) return next(null, null)
    // Pull in a new chunk of text,
    // removing it from the string.
    var chunk = string.slice(0, size)
    string = string.slice(size)
    // Emit "chunk" from the stream.
    next(null, chunk)
  })
}
// pipe "hello world" out
// to stdout.
fromString('hello world').pipe(process.stdout)
stream = from2.obj([opts], read)
Shorthand for from2({ objectMode: true }, read).
createStream = from2.ctor([opts], read)
If you're creating similar streams in quick succession you can improve performance by generating a stream constructor that you can reuse instead of creating one-off streams on each call.
Takes the same options as from2, instead returning a constructor which you
can use to create new streams.
See Also
- from2-array - Create a from2 stream based on an array of source values.
- from2-string - Create a stream from a string. Sugary wrapper around from2.
License
MIT. See LICENSE.md for details.
