quirks with subject searching

[David Bremner]

Matthew Lear <matt at bubblegen.co.uk> writes:
>
> item: foo
> an item: foo
> an item: XYfoo1234
> an item: XYfoo bar
>
> ... only the first two are found.
>
> Also:
> * notmuch searching for subject:"item: f" gives zero results.

notmuch (and xapian) are based on searching for words, not
substrings. It only finds subwords through a process of stemming [1]. 

>
> * notmuch searching for subject:"(*foo*)" results in the first two threads
> being found and also a thread with the word footprint in the middle of the
> subject being found (subject is "memory footprint without feature").

wildcards [2] are supported only at the end of words, so I suppose the first
* is just ignored.

>
> Why doesn't notmuch search subject:foo find all four threads, and why
> doesn't notmuch search subject:"item: f" find anything at all?

Hopefully the above clears it up. This topic comes up fairly often; I'm
not sure if there is something we could add to the  (already rather
long) notmuch-search-terms manpage that would help.


[1] "Stemming" in notmuch-search-terms (7)
[2] "Wildcards" in notmuch-search-terms (7)