Various fixes and improvements to module linting

[Maelan]

This PR consists of incremental fixes and simplifications and is best reviewed per commit, with help from the (long) commit messages.

Although some of the bugs fixed were made obvious by the new type linter, they existed since the beginning of the Git history, years ago. The most notable bugfixes are:

• the linting of module type of (was not working in signatures);
• the linting of functor parameters (X: T) (was not working in signatures);
• the linting of the functor construct (was not working except in one situation).

Test suite for module type of (comments indicate behavior before this PR):

(* approximately ok:
 *   - "module type of" linted as ocamlKeyword
 *   - "F" linted as ocamlModule
 *   - "(X)" linted meaninglessly but by chance it doesn’t look SO bad
 *)
module N : module type of F(X)

module M : sig
  (* not ok:
   *   - "module" linted as ocamlMPRestr3
   *   - "type" understood as starting a type definition
   *   - "of", "X" linted meaninglessly
   *)
  module N : module type of X
  (* not ok, failure made obvious by the new type linter:
   *   - "F(X)" understood as the beginning of "F(X).t" with dot missing
   *     => error linting, spectacular failure
   *)
  module N : module type of F(X)
  val x : int
end

Test suite for functor parameters:

module M : sig
  module F () (X : Ord) : sig end (* not ok *)
end
= struct
  module F () (X : Ord) : sig end = struct end (* ok *)
end

module F () (X : Ord) : sig end = struct end (* ok *)

Test suite for functor:

module M : sig
  module type F
    = functor () (X : Ord) -> sig end (* not ok *)
  module F
    : functor () (X : Ord) -> sig end (* ok *)
end
= struct
  module type F
    = functor () (X : Ord) -> sig end (* not ok *)
  module F
    : functor () (X : Ord) -> sig end (* not ok *)
    = functor () (X : Ord) -> struct end (* not ok *)
end

module type F
  = functor () (X : Ord) -> sig end (* not ok *)
module F
  : functor () (X : Ord) -> sig end (* not ok *)
  = functor () (X : Ord) -> struct end (* not ok *)

This PR closes

• issue Parentice highlighting error in vim #3 (was actually already addressed by a previous PR, but the new PR addresses the small remaining bit—highlighting : on module)
• issue bad coloring of module types #91 (both bugs)

Note: the module linting stuff has more bugs that I did not care fixing, because I am not in mood for rewriting it from scratch. I cannot figure out the purpose of several bits, neither if some bits are astute hacks, obsolete stuff or just mistakes. For instance, issue #6 remains unsolved; I saw which part of the code causes it, it seems to be done on purpose?

[copy]

Thanks!

I tested this against some files by diffing the output of :TOhtml and found some things look slightly worse than before:

module F : Bar = Foo

module Test : Make(Int).S = struct end

(Foo, Int and S are highlighted as constructors).

Besides that, this is a clear improvement, and I hope we can get this merged.

I cannot figure out the purpose of several bits, neither if some bits are astute hacks, obsolete stuff or just mistakes. For instance, issue #6 remains unsolved; I saw which part of the code causes it, it seems to be done on purpose?

It should be fine as long as the highlighting doesn't fail catastrophically (as in #91). After all, it looks like a strict improvement with this patch (at least until Simon discovers some new alien syntax :-))

[copy]

I'll merge this, as it's clearly better than before.

[Maelan]

Great, thank you!