stream to echo_via_pager

[untitaker]

There should be a possibility to launch the pager while still generating the data it is supposed to show. Proposed API:

with echo_via_pager() as f:
    f.write('foobar')

[mitsuhiko]

I think this might be impossible to support given how the pager fallbacks work.

[untitaker]

In that case I think it makes sense to just skip the fallbacks that don't support this.

I need this because I want to write something like git log, and want to immediately show something instead of buffering the whole log.

[meejah]

+1
I'm currently working around this by collecting all my lines in some list and then echoing them, but for large inputs this can take a while (and, obviously, for really large inputs, exhaust memory). So, the user experience is bad for large inputs since it appears nothing is happening...

[stefreak]

I pushed a solution using generators. I'd love to get some early feedback and would finish the implementation if the design is pleasing :)