chopper

Cuts a stream into discrete pieces using a delimiter

Chopper

Chops a stream into pieces using a delimiter.

$ npm install chopper

The object created from StreamChopper() lets you read a line at a time from a stream in a throttled manner:

require("chopper");

stream = process.stdin
var chopper = new StreamChopper(stream, "\n", function(line) {
    chopper.pause();
    console.log(line);
    setTimeout(function() {
        chopper.resume();
    }, 500);
});

This outputs a line at a time with a 1/2 second delay between each.

All three arguments to the constructor are required.

The object created from Chopper() cuts the stream into delimited pieces, but does not throttle itself at all. The stream for Chopper() is just sequentials calls to feed it more data via next().

Chopper() can be used 3 different ways.

This:

log = console.log
var chopper = new Chopper("\0");
log(chopper.next('{"seq":0}\0'));
log(chopper.next('{"seq":1}\0'));
log(chopper.next('{"seq":'));
log(chopper.next('2}\0'));
log(chopper.next('{"seq":3}\0{"seq":4}\0'));
log(chopper.next('{"seq":5}\0{'));
log(chopper.next('"seq":6}\0'));
log(chopper.next('\0'));
log(chopper.next('{"seq":7}\0{"seq":8}\0{"seq":9}'));
log(chopper.next('\0{"seq":10}'));

Outputs:

[ '{"seq":0}' ]
[ '{"seq":1}' ]
[]
[ '{"seq":2}' ]
[ '{"seq":3}', '{"seq":4}' ]
[ '{"seq":5}' ]
[ '{"seq":6}' ]
[ '' ]
[ '{"seq":7}', '{"seq":8}' ]
[ '{"seq":9}' ]

This:

var chopper = new Chopper("\n");
var f = function(m) { log(m) }
chopper.next('{"seq":0}\n', f)
chopper.next('{"seq":1}\n', f)
chopper.next('{"seq":', f)
chopper.next('2}\n', f)
chopper.next('{"seq":3}\n{"seq":4}\n', f)
chopper.next('{"seq":5}\n{', f)
chopper.next('"seq":6}\n', f)
chopper.next('\n', f)
chopper.next('{"seq":7}\n{"seq":8}\n{"seq":9}', f)
chopper.next('\n{"seq":10}', f)

Outputs this:

{"seq":0}
{"seq":1}
{"seq":2}
{"seq":3}
{"seq":4}
{"seq":5}
{"seq":6}

{"seq":7}
{"seq":8}
{"seq":9}

This:

var f = function(m) { log(m) }
var chopper = new Chopper("\n", f);
chopper.next('Hello.\nGoodbye.\n')
chopper.next('Why')
chopper.next(' are you')
chopper.next(' here?\nI do not know.')
chopper.next('\nok')

Outputs this:

Hello.
Goodbye.
Why are you here?
I do not know.

The "ok" string at the end isn't recognized as it isn't terminated with \n.

If you find errors please send me pull requests with repairs.