index.js•1.46 kB
'use strict';
var Stream = require('stream')
// from
//
// a stream that reads from an source.
// source may be an array, or a function.
// from handles pause behaviour for you.
module.exports =
function from (source) {
if(Array.isArray(source)) {
var source_index = 0, source_len = source.length;
return from (function (i) {
if(source_index < source_len)
this.emit('data', source[source_index++])
else
this.emit('end')
return true
})
}
var s = new Stream(), i = 0
s.ended = false
s.started = false
s.readable = true
s.writable = false
s.paused = false
s.ended = false
s.pause = function () {
s.started = true
s.paused = true
}
function next () {
s.started = true
if(s.ended) return
while(!s.ended && !s.paused && source.call(s, i++, function () {
if(!s.ended && !s.paused)
process.nextTick(next);
}))
;
}
s.resume = function () {
s.started = true
s.paused = false
next()
}
s.on('end', function () {
s.ended = true
s.readable = false
process.nextTick(s.destroy)
})
s.destroy = function () {
s.ended = true
s.emit('close')
}
/*
by default, the stream will start emitting at nextTick
if you want, you can pause it, after pipeing.
you can also resume before next tick, and that will also
work.
*/
process.nextTick(function () {
if(!s.started) s.resume()
})
return s
}