Re: Boolean word/regexp search problem

[Matt Lundin <mdl@imapmail.org>]

Hi Carsten,

Matthew Lundin <mdl@imapmail.org> writes:

> Matt Lundin <mdl@imapmail.org> writes:
>
>> The word/regexp agenda search to work with more than one word or regexp
>> unless the first word or regexp is also preceded by a "+" or "-".

I've investigated this further and beg your permission to offer a few
comments/suggestions.

First, I apologize for missing the change in behavior in the
org-search-view introduced in Org 6.32. Reading the ChangeLog, I now see
the following information:

,----
| Agenda Search view: Search for substrings
| 
| The default in search view (C-c a s) is now that the search expression
| is searched for as a substring, i.e. the different words must occur in
| direct sequence, and it may be only part of a word. If you want to
| look for a number of separate keywords with Boolean logic, all words
| must be preceded by + or -.
| 
| This was, more-or-less, requested by John Wiegley.
`----

In particular, I see that "all words must be preceded by + or -" for a
boolean search. I've also read the manual section 10.3.5 as well as the
docstring for org-search-view and appreciate that this new behavior can
be turned off with the variable
org-agenda-search-view-search-words-only.

A few comments:

1) I'm wondering whether the substring search should be the default. I
search quite often for two or three words or regexps that I know are in
an entry (regardless of order), while I rarely search for a specific
phrase or sequence of words. Of course, others might disagree.

2) Many web and database search engines use the following convention: a
space between words becomes an automatic AND, while quotation marks
indicate searches for a phrase/substring (i.e., words in sequence).
Having missed the description of the new behavior in the ChangeLog, I
found the new default substring search a bit counter-intuitive. My vote
would be for sloppy boolean searches by default, with quotation marks
reserved for substring searches. But of course, this is not a huge
priority for org-mode development, and I have no idea how difficult it
would be to implement!

3) The new substring search changes the behavior of regexp searches. A
simple regexp search with brackets (e.g, {Carst}) no longer produces any
results unless the brackets are preceded by a +. This is true even if
one is searching only for a single regexp. In other words, regexp
brackets now *must* always be preceded by a plus or a minus. Is this the
intended behavior?

4) Pressing "[" or "]" or "{" or "}" in the agenda buffer adds a "+" or
"-" after the first term in the minibuffer. E.g.,

--8<---------------cut here---------------start------------->8---
[+-]Word/{Regexp} ...: Emacs +
--8<---------------cut here---------------end--------------->8---

But if the user simply adds another term at the cursor (i.e., after the
"+"), the search will fail, since "Emacs" now must also be preceded by a
"+".

Thanks for reading this long email.

- Matt