I'm new to the 4coder customization layer, and I'm trying do add support for the zig programming language.

How can I create a custom lexer? and use it to have syntax highlighting on zig files.

If you only want basic syntax highlighting you can do something like "Adding keywords to the syntax highlighting" from the wiki (using the draw_string_highlights method).

If you really want a lexer, you'd better ask Allen on the 4coder discord or by e-mail. To my knowledge it's kind of hard to do in the current version, but I've never tried it.