ctags regex for multiple declarations in one line

Question

I'm writing a .ctags file for a custom language... Like most languages, it allows for multiple variable declarations in one line.. i.e.:

int a, b, c;

I have a basic regex which recognizes 'a':

--regex-mylang=/^[ \t]*int[ \t]*([a-zA-Z_0-9]+)/\1/v,variable/

How do I modify this to have it match 'b' and 'c', as well? I can't find anything in ctags documentation that deals with multiple matches in a single line.

Answer 1

The latest Universal-ctags can capture them.

[jet@localhost]/tmp% cat input.x 
int a, b, c;

[jet@localhost]/tmp% cat x.ctags 
--langdef=X
--map-X=.x

--kinddef-X=v,var,variables
--_tabledef-X=main
--_tabledef-X=vardef

--_mtable-regex-X=main/int[ \t]+//{tenter=vardef}
--_mtable-regex-X=main/.//

--_mtable-regex-X=vardef/([a-zA-Z0-9]+)/\1/v/
--_mtable-regex-X=vardef/;//{tleave}
--_mtable-regex-X=vardef/.//


[jet@localhost]/tmp% u-ctags --options=x.ctags -o - ./input.x 
a   ./input.x   /^int a, b, c;$/;"  v
b   ./input.x   /^int a, b, c;$/;"  v
c   ./input.x   /^int a, b, c;$/;"  v

See https://docs.ctags.io/en/latest/optlib.html#advanced-pattern-matching-with-multiple-regex-tables for more details.

Answer 2

After going through this for a few hours, I'm convinced it can't be done. No matter what, the regular expression will only expand to one tag per line. Even if you put \1 \2 \3 ... as the expansion, that would just cause a tag consisting of multiple matches, instead of one tag per match.

It parses the C example correctly because inside the ctags source code it uses an actual code parser, not a regexp.