Better mapping.
Works with
$ = ;// $.map(fn)
When returning a promise, it is mapped asynchronously (in parallel):
var Q = ;// ...
The stream 'end' event delayed until all promisses are finished.
When you return undefined
from your promise or regular function, the file is
filtered from the stream.
That's it.
Alternatives
For regular callback style mapping, just use map-stream
.
var map = ;// ...
For both data
and end
events, through2
works well:
var Through = obj;// ...