Problem with ocamllex syntax

[correnson]

It seems that ocp-indent works badly with parsing rules in .mll files. However, it is automatically activated by the tuareg hook.

• should it work with?
• is there any workaround?

[william3]

+1, I am having a really bad time with .mll and .mly files

[AltGr]

Indeed, syntax for .mll and .mly files is quite different.

• there is very basic support for .mll, that can be enabled with --syntax=mll (it indents rule _ = parse better, but let _ = regexp+ for example needs additional parentheses or ocp-indent will consider + as the binary operator it normally is). The emacs mode should automatically enable this on .mll files but doesn't at the moment. You can do this manually for all ocaml files by customising ocp-indent-syntax, or to temporarily do it just on the current buffer:

M-: (setq-local ocp-indent-syntax '("mll"))

• there is no support for .mly at the moment ; latest ocp-indent should not load when it detects that the file matches *.mly, but tuareg doesn't do much better.

In any case, you can locally disable ocp-indent while in tuareg-mode using

M-: (progn (kill-local-variable 'indent-line-function) (kill-local-variable 'indent-region-function) (tuareg--common-mode-setup))

[correnson]

Thanks for those tips!

It would be great to have ocp-indent automatically disabled from tuareg on mll and mly files until a better support for them. I'd share some workaround as soon as I have some.