[m-rev.] for post-commit review: reorder the interface of io.m

[Peter Wang]

On Wed, 30 Oct 2019 09:10:52 +1100 (AEDT), "Zoltan Somogyi" <zoltan.somogyi at runbox.com> wrote:
> I am not attaching the diff, because it is a mess. Instead, I am asking
> any volunteer reviewer to read the updated interface section of io.m.
> 
> I am committing the change because while the new order may not be
> perfect, it is definitely much better than what went before.

It looks much better.

format doesn't quite belong in the "Writing out several values" section.
Perhaps add a "Formatted output" section before that section, even if it
contains just the two predicates.

The "Whole file text input predicates" section contains two predicates
that work on binary input streams. You could remove "text" from the
section title.

Peter