doc: notmuch help search-terms, boolean operators

[Olly Betts]

On Tue, Apr 26, 2011 at 04:01:17PM -0700, Carl Worth wrote:
> On Wed, 27 Apr 2011 00:24:38 +0200, Florian Friesdorf <flo at chaoflow.net> wrote:
> > Through playing with `notmuch tag` and `notmuch search
> > --output=messages` I found:
> > 
> > Complete list of boolean operators in order of precedence:
> > - NOT
> > - AND
> > - XOR
> > - OR
> > 
> > Is this correct? If yes, I would extend the manpage accordingly.
> 
> Currently, notmuch doesn't implement this behavior but relies on
> Xapian's query parser to do so. As such, I'd really prefer to see
> Xapian's documentation augmented here before we start documenting
> any particular behavior in notmuch.
> 
> Olly, is the above list of operators complete and in the correct order
> of  precendence?

Close, but actually AND and NOT have equal precedence.

Also, NEAR and ADJ bind tighter than AND or NOT.

And '+' and '-' tightest of all.

I'll try to make sure this gets documented.

Cheers,
    Olly