Re: make `occur' use word at point as default

[Juri Linkov]

>> 1. word at point - (current-word t)
>> 2. tag at point - (funcall (or find-tag-default-function
>>                            (get major-mode 'find-tag-default-function)
>>                            'find-tag-default))
>
> These are pretty much the same.  More specifically the tag should include
> the current-word as a substring, so I'd drop the number 1 and just keep
> number 2.

I agree.

>> 3. active region - (and transient-mark-mode mark-active
>>                         (buffer-substring-no-properties
>>                          (region-beginning) (region-end)))
>
> You could have done M-w before the current operation.  Much simpler/quicker
> than doing M-n M-n M-n searching for it.

>> 5. last kill from the kill ring - (current-kill 0)
>
> C-y brings it more quickl;y and reliably than M-n M-n M-n M-n.

Doing M-w/C-y is simpler only for strings that don't contain special
regexp characters.  But in regexps they need to be quoted.  `M-n M-n ...'
could provide a default value with quoted special regexp characters.

>> 4. last isearch regexp - (car regexp-search-ring)
>
> This one makes sense.  Maybe we could simply use the same ring for occur as
> for regexp-search so that it is available as M-p.

There is also another command that reads a regexp and that could share
the same regexp ring - `query-replace'.  It has a special variable
`query-replace-from-history-variable' that defines the history list to use.
So `occur' and `isearch' could have similar variables to allow
occur/multi-occur/keep-lines/flush-lines/how-many and isearch-regexp
to use the same ring with either:

(setq regexp-history-variable 'regexp-history)
(setq regexp-search-ring-variable 'regexp-history)

or:

(setq regexp-history-variable 'regexp-search-ring)
(setq regexp-search-ring-variable 'regexp-search-ring)

-- 
Juri Linkov
http://www.jurta.org/emacs/