Ctags regex for multiple ads on the same line

Question

I am writing a .ctags file for a custom language ... Like most languages, it allows multiple variable declarations on the same line .. ie:

int a, b, c; 

I have a basic regex that recognizes "a":

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

How can I change this to match 'b' and 'c'? I can't find anything in the ctags documentation that deals with multiple matches on the same line.

Answer 1

After going through this in a few hours, I am convinced that this is impossible. Regardless, the regex will only expand to one tag per line. Even if you put \ 1 \ 2 \ 3 ... as an extension, it will simply trigger a tag consisting of several matches, instead of one tag per match.

It parses the C example correctly, because the actual parser of the code is used inside the ctags source code, not the regular expression.

Answer 2

recent 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.xa ./input.x /^int a, b, c;$/;" v b ./input.x /^int a, b, c;$/;" v c ./input.x /^int a, b, c;$/;" v 

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

Answer 3

You are trying to parse with a regular expression, which is usually not possible. Analysis requires the equivalent of storing information about the stack, but a regular expression can only contain a finite number of different states.

Answer 4

it can be partially implemented using Universal Ctags and using the flags {_multiline=N} and {scope} . N is the number of the group whose position is stored in the generated tags file. For more information, see here: docs / optlib.rst

Configuration: mylang.ctags

 --langmap=mylang:.txt --regex-mylang=/^[[:blank:]]*(int)[[:blank:]]/\1/{placeholder}{scope=set}{_multiline=1} --regex-mylang=/(;)/\1/{placeholder}{scope=clear} --regex-mylang=/[[:blank:]]*([[:alnum:]]+)[[:blank:]]*,?/\1/v,variable/{_multiline=1}{scope=ref} 

Test file: test.txt

 void main() { int a, b, c, d; } 

Create tags with: ctags --options=mylang.ctags test.txt

Generated tags file:

 !_TAG_FILE_FORMAT 2 /extended format; --format=1 will not append ;" to lines/ !_TAG_FILE_SORTED 1 /0=unsorted, 1=sorted, 2=foldcase/ !_TAG_OUTPUT_MODE u-ctags /u-ctags or e-ctags/ !_TAG_PROGRAM_AUTHOR Universal Ctags Team // !_TAG_PROGRAM_NAME Universal Ctags /Derived from Exuberant Ctags/ !_TAG_PROGRAM_URL https://ctags.io/ /official site/ !_TAG_PROGRAM_VERSION 0.0.0 /cb4476eb/ a test.txt /^ int a, b, c, d;$/;" v b test.txt /^ int a, b, c, d;$/;" v c test.txt /^ int a, b, c, d;$/;" v d test.txt /^ int a, b, c, d;$/;" v int test.txt /^ int a, b, c, d;$/;" v main test.txt /^void main() {$/;" v void test.txt /^void main() {$/;" v 

Answer 5

 --regex-perl=/^\s*?use\s+(\w+[\w\:]*?\w*?)/\1/u,use,uses/ --regex-perl=/^\s*?require\s+(\w+[\w\:]*?\w*?)/\1/r,require,requires/ --regex-perl=/^\s*?has\s+['"]?(\w+)['"]?/\1/a,attribute,attributes/ --regex-perl=/^\s*?\*(\w+)\s*?=/\1/a,aliase,aliases/ --regex-perl=/->helper\(\s?['"]?(\w+)['"]?/\1/h,helper,helpers/ --regex-perl=/^\s*?our\s*?[\ $@ %](\w+)/\1/o,our,ours/ --regex-perl=/^=head1\s+(.+)/\1/p,pod,Plain Old Documentation/ --regex-perl=/^=head2\s+(.+)/-- \1/p,pod,Plain Old Documentation/ --regex-perl=/^=head[3-5]\s+(.+)/---- \1/p,pod,Plain Old Documentation/