Opal-Estate-Pro/node_modules/split/index.js
2019-09-13 11:27:52 +07:00

60 lines
1.3 KiB
JavaScript

//filter will reemit the data if cb(err,pass) pass is truthy
// reduce is more tricky
// maybe we want to group the reductions or emit progress updates occasionally
// the most basic reduce just emits one 'data' event after it has recieved 'end'
var through = require('through')
var Decoder = require('string_decoder').StringDecoder
module.exports = split
//TODO pass in a function to map across the lines.
function split (matcher, mapper) {
var decoder = new Decoder()
var soFar = ''
if('function' === typeof matcher)
mapper = matcher, matcher = null
if (!matcher)
matcher = /\r?\n/
function emit(stream, piece) {
if(mapper) {
try {
piece = mapper(piece)
}
catch (err) {
return stream.emit('error', err)
}
if('undefined' !== typeof piece)
stream.queue(piece)
}
else
stream.queue(piece)
}
function next (stream, buffer) {
var pieces = (soFar + buffer).split(matcher)
soFar = pieces.pop()
for (var i = 0; i < pieces.length; i++) {
var piece = pieces[i]
emit(stream, piece)
}
}
return through(function (b) {
next(this, decoder.write(b))
},
function () {
if(decoder.end)
next(this, decoder.end())
if(soFar != null)
emit(this, soFar)
this.queue(null)
})
}