Minor refactor. line_discipline.go was home to 2 large structs (lineDiscipline
and queue), and queue is now large enough IMO to get its own file.
Also moves queue locks into the queue struct, making locking simpler.
PiperOrigin-RevId: 200080301
Change-Id: Ia75a0e9b3d9ac8d7e5a0f0099a54e1f5b8bdea34
Adds support for echo to terminals. Echoing is just copying input back out to
the user, e.g. when I type "foo" into a terminal, I expect "foo" to be echoed
back to my terminal.
Also makes the transform function part of the queue, eliminating the need to
pass them around together and the possibility of using the wrong transform for a
queue.
PiperOrigin-RevId: 199655147
Change-Id: I37c490d4fc1ee91da20ae58ba1f884a5c14fd0d8
Kevin Krakauer
Cyrille Hemidy
Googler