Highlight types based on syntax

[copy]

Currently there's a hard-coded list of built-in type names that are highlighted specially even when the name is used as an identifier. Custom type names, on the other hand, are not highlighted.

See:

type foo = {
  a: int;
  b: bar;
}

let string = string_of_int

[rdavison]

Although this might be possible from within a type definition, like in your example, I can't think of a way of doing this using vim's regular expresions to highlight types across the codebase without using a more powerful tool like Merlin to parse the source code and return all the tokens and how they should be highlighted.

[struktured]

+1 this would be a great addition if such a thing existed but I agree it requires compiler symbols to work properly.

[rgrinberg]

Note that people did manage something this fancy with clang. https://github.com/jeaye/color_coded I think it requires quite a bit of hackery.

[rdavison]

I've dug around in the source code of merlin and it appears there might be a stubbed out place where such a thing could go https://github.com/ocaml/merlin/blob/master/src/frontend/query_commands.ml#L140

Not sure what the plan is for that particular query command, but I could portentially see that as being our hook for better syntax highlighting.

I've attempted to get that query command to return useful things on my spare time... but I haven't been satisfied with the result so I haven't published anything yet.

[XVilka]

Would be nice to have something like https://github.com/numirias/semshi

[copy]

This will probably be supported by the tree-sitter project. There's already an OCaml grammar and a PR for neovim.

[Maelan]

tree-sitter should be the definitive answer to this. However it is not available in Neovim yet, let alone plain Vim.

FYI, I am hacking runtime/syntax/ocaml.vim to highlight types separately from expressions. It is very ad hoc but approximately works, with some corner cases. I will submit a PR at some point.

[XVilka]

Tree-sitter is planned for NeoVim 0.5 version: neovim/neovim#10124

[undu]

There's an intention to have a separate parser for .ml and .mli (and there's a specialized one for .mll).

I'm double checking how nvim-treesitter will handle with this, we might need to have one filetype per file extension to support multiple tree-sitter parsers instead of using ocaml for all of them.

[rgrinberg]

I think this can safely be closed. Let's keep the regex based syntax highlighting simple and let the tree sitter grammar handle complex cases.

[copy]

I think this can safely be closed. Let's keep the regex based syntax highlighting simple and let the tree sitter grammar handle complex cases.

Agreed!