Add ctags implementation

[steveno]

I think adding a parser to ctags would be a good step for zig. I'd be willing to help whip up something basic if someone wants to "mentor" me.

https://github.com/universal-ctags/ctags

[andrewrk]

I'd be happy to mentor this. What approach do you plan to take?

• update ctags to support zig syntax
• (discouraged) improve c++ zig compiler and add feature for outputting ctags file
• improve self hosted compiler parser and add a feature for outputting ctags file

[steveno]

My initial plan was to fork ctags and begin adding a parser to it. When its reached a level you were happy with we could open a pull request. I've worked on that project a (very) small amount before so I'm sure they would accept the contribution if it's up to snuff.

[andrewrk]

Sounds like a good plan to me. Here are some resources:

• informal grammar description: https://ziglang.org/documentation/master/#Grammar
• c++ tokenizer implementation
• self hosted tokenizer implementation
• c++ parser implementation
• self hosted parser implementation

A couple more notes:

• The syntax of zig is still not stabilized. It is likely to change, perhaps even drastically, in the next few releases.
• One approach you could take is to create a zig project which takes the self hosted parser/tokenizer from the standard library and exports a C API on top of that. Then ctags could add a (optional) dependency on that library for zig support.

[isaachier]

I was just looking into this. The parsers range in complexity. For example, compare Myrrdin's parser with the C++ parser. Easiest for now might be to make a zig implementation using existing parser and then port to C once language stabilizes.

[isaachier]

I got something up and running. Needs a bit more work, but here it is: https://github.com/isaachier/ztags.

[andrewrk]

well done!

[andrewrk]

@isaachier want to start a wiki page for zig projects so that your project can get some visibility?

[isaachier]

Good idea. I'll do that now.

[watzon]

I added instructions to the tagbar wiki and referenced ztags in there.

[uniquepointer]

Is adding regex to the .ctags still the best way to get a tags file? Would be nice to have something more official but beggars can't be choosers, I understand its not a priority. I would offer to help tackle this in the "official" manner I speak of, but I am not very well versed in the Zig core.

[pierre-rouleau]

@andrewrk Is ztag still the way to go for current Zig? The site states that only version 0.13 is supported and I can build it with 0.15.1:

>0@11:42:33 L3 :[~/my/dvo/zig-repos/ztags]  git:(master)ztags                                                                                                               
zsh% zig build                                                                                                                                                                             
/Users/roup/my/dvo/zig-repos/ztags/build.zig.zon:2:13: error: expected enum literal                                                                                                        
    .name = "ztags",                                                                                                                                                                       
            ^~~~~~~                                                                                                                                                                        
>1@11:59:02 L3 :[~/my/dvo/zig-repos/ztags]  git:(master)ztag