Re: [PATCH v6] userdiff: add builtin diff driver for kotlin language.

[jaydeepjd.8914@gmail.com]

On 3/12/22 1:37 AM, Johannes Sixt <j6t@kdbg.org> wrote:
> Am 11.03.22 um 08:27 schrieb Jaydeep P Das:
> > The xfuncname pattern finds func/class declarations
> > in diffs to display as a hunk header. The word_regex
> > pattern finds individual tokens in Kotlin code to generate
> > appropriate diffs.
> >
> > This patch adds xfuncname regex and word_regex for Kotlin
> > language.
> >
> > Signed-off-by: Jaydeep P Das <jaydeepjd.8914@gmail.com>
> > ---
> 
> Thank you. At first, I thought this round is it, but then I noticed this
> line:
> 
> > +<RED>0xFF_EC_DE_5E 0b100_000 1<RESET><GREEN>0xFF_E1_DE_5E 0b100_100 2<RESET>00_000
> 
> Notice how the change from 100_000 to 200_000 breaks out the first digit
> into its own token.

Wow. I completely missed it.

> > diff --git a/userdiff.c b/userdiff.c
> > index 8578cb0d12..c416c9b426 100644
> > --- a/userdiff.c
> > +++ b/userdiff.c
> > @@ -168,6 +168,18 @@ PATTERNS("java",
> >   	 "|[-+0-9.e]+[fFlL]?|0[xXbB]?[0-9a-fA-F]+[lL]?"
> >   	 "|[-+*/<>%&^|=!]="
> >   	 "|--|\\+\\+|<<=?|>>>?=?|&&|\\|\\|"),
> > +PATTERNS("kotlin",
> > +	 "^[ \t]*(([a-z]+[ \t]+)*(fun|class|interface)[ \t]+.*)$",
> > +	 /* -- */
> > +	 "[a-zA-Z_][a-zA-Z0-9_]*"
> > +	 /* hexadecimal and binary numbers */
> > +	 "|0[xXbB][0-9a-fA-F_]+[lLuU]*"
> > +	 /* integers and floats */
> > +	 "|[0-9][0-9_]*([.][0-9_]*)([Ee][-+]?[0-9]+)?[fFlLuU]*"
> 
> This line matches a non-empty digit sequence of any length, and I
> thought the longest match would win. Why is that not the case here?
> Frankly, I'm scratching my head over it. Any ideas?

Yes. The capture group ([.][0-9_]*) should occur once or zero times. So
this `([.][0-9_]*)?` will fix it.