[notmuch] JSON output as default [was: Re: [PATCH] Add an "--output=(json|text|)" command-line option...]

[racin at free.fr]

> > I definitely want to be able to pipe single-field lists coming from
> > notmuch to grep, xargs, shell for loops, etc. without having to
> decode
> > JSON.
> 
> While I would love to see JSON (even by default), I agree. If I just
> want to code up a notmuch-based address book with sth like:
> 
> notmuch show to:Diana --output=to --sort=relevance --limit=20
> 
> just getting back a plain list of mail addresses is the easiest to
> handle.

This would also be useful for the Emacs/Vim interfaces. For instance, my smart completion patch
would really benefit from notmuch being capable of outputing various fields in all messages in plain text
separated by newlines (this is even easier to handle in emacs code than JSON). In fact, most of the C code I had
to write for this patch is better replaced by the --output option...