Re: font-lock regexp for complementary keywords

[Dieter Wilhelm]

Thanks to Kevin and Johan

with your help I ended up having 3 working regexps to choose from ;-).

"fil\\(?:n\\(?:a\\(?:me?\\)?\\)?\\)?"
"/fil\\(n\\(a\\(me?\\)?\\)?\\)?"
"/fil\\(name\\|nam\\|na\\|a\\)"

I'll choose the first because it is supposed to be optimised (even
though it looks the most complicated).

bojohan+news@dd.chalmers.se (Johan Bockgård) writes:

> Dieter Wilhelm <dieter@duenenhof-wilhelm.de> writes:
>>
>> /fil and
>> /filn and
>> /filna and
>> /filnam and
>> /filname and

>
> (regexp-opt
>  '("fil"
>    "filn"
>    "filna"
>    "filnam"
>    "filname"))
>
> =>
>
> "fil\\(?:n\\(?:a\\(?:me?\\)?\\)?\\)?"

Emacs never ceases to astonish, I didn't know  regexp-opt exists.

> Kevin Rogers wrote:

> > \\(/fil\\) 1 font-lock...
> > /fil\\(n\\) 1 fon...
> > /filn\\(a\\) 1 ...
> > /filna\\(m\\) 1 ...
> > /filnam\\(e\\) 1 ...

> Why are you grouping and highlighting either "/fil" or the last letter?

because a previous font-lock regexp fontifies already the letters in
between, somehow I thought this more efficient than overwriting the
previous fontifications.

> "/fil\\(n\\(a\\(me?\\)?\\)?\\)?\\>" 0 font-lock...

I see, 0 means then all levels of groupings, good to know, thanks.

> > Originally I thought that something like this
> >
> > /fil\\(n\\|na\\|nam\\|name\\)

interesting enough, just the order was wrong not the principle

/fil\\(name\\|nam\\|na\\|a\\)

does the trick and for my brain it looks the easiest.

-- 
    Best wishes

    H. Dieter Wilhelm
    Darmstadt, Germany