Syntax: Fixes to type declarations

Fix tupled type params, += and whitespaces around keywords.
Add examples to the test file.

Author: Julow

syntax/ocaml.vim

@@ -468,13 +468,14 @@ hi link ocamlTypeSumAnnot ocamlTypeCatchAll
 syn region ocamlTypeDefImpl
 \ matchgroup=ocamlKeyword start="\<of\>"
 \ matchgroup=ocamlKeyChar start=":="
+\ matchgroup=ocamlKeyChar start="+="
 \ matchgroup=ocamlKeyChar start=":"
 \ matchgroup=ocamlKeyChar start="="
-\ matchgroup=NONE end="\(\<type\>\|\<exception\>\|\<val\>\|\<module\>\|\<class\>\|\<method\>\|\<constraint\>\|\<inherit\>\|\<object\>\|\<struct\>\|\<open\>\|\<include\>\|\<let\>\|\<external\>\|\<in\>\|\<end\>\|)\|]\|}\|;\|;;\)\@="
+\ matchgroup=NONE end="\(\<type\>\|\<exception\>\|\<val\>\|\<module\>\|\<class\>\|\<method\>\|\<constraint\>\|\<inherit\>\|\<object\>\|\<struct\>\|\<open\>\|\<include\>\|\<let\>\|\<external\>\|\<in\>\|\<end\>\|)\|]\|}\|;\|;;\|=\)\@="
 \ matchgroup=NONE end="\(\<and\>\)\@="
 \ contained skipwhite skipempty
 \ contains=@ocamlTypeExpr,ocamlTypePrivate,ocamlTypeDefDots,ocamlTypeRecordDecl,ocamlTypeSumDecl,ocamlComment,ocamlPpx
-\ nextgroup=ocamlTypeDefAnd
+\ nextgroup=ocamlTypeDefImpl,ocamlTypeDefAnd
 hi link ocamlTypeDefImpl ocamlTypeCatchAll
 
 " Type context opened by “type” (type definition) and “constraint” (type
@@ -484,7 +485,7 @@ hi link ocamlTypeDefImpl ocamlTypeCatchAll
 syn region ocamlTypeDef
 \ matchgroup=ocamlKeyword start="\<type\>\(\_s\+\<nonrec\>\)\?\|\<constraint\>"
 \ matchgroup=ocamlTypeIdentifier end="\<\l\(\w\|'\)*\>"
-\ contains=@ocamlAllErrs,ocamlComment,ocamlTypeVariance,ocamlTypeVar,ocamlWhite
+\ contains=@ocamlTypeExpr,@ocamlAllErrs,ocamlComment,ocamlTypeVariance,ocamlTypeVar,ocamlPpx,ocamlWhite
 \ skipwhite skipempty
 \ nextgroup=ocamlTypeDefImpl,ocamlTypeDefAnd
 
@@ -495,15 +496,15 @@ syn region ocamlTypeDef
 syn region ocamlTypeDefAnd
 \ matchgroup=ocamlKeyword start="\<and\>"
 \ matchgroup=ocamlTypeIdentifier end="\<\l\(\w\|'\)*\>"
-\ contains=@ocamlAllErrs,ocamlComment,ocamlTypeVariance,ocamlTypeVar,ocamlWhite
+\ contains=@ocamlTypeExpr,@ocamlAllErrs,ocamlComment,ocamlTypeVariance,ocamlTypeVar,ocamlPpx,ocamlWhite
 \ skipwhite skipempty
 \ nextgroup=ocamlTypeDefImpl,ocamlTypeDefAnd
 
 " Exception definitions. Like ocamlTypeDef, jump into ocamlTypeDefImpl.
 syn region ocamlExceptionDef
 \ matchgroup=ocamlKeyword start="\<exception\>"
 \ matchgroup=ocamlConstructor end="\u\(\w\|'\)*\>"
-\ contains=@ocamlAllErrs,ocamlComment,ocamlTypeVariance,ocamlTypeVar
+\ contains=@ocamlAllErrs,ocamlComment,ocamlTypeVariance,ocamlTypeVar,ocamlPpx
 \ skipwhite skipempty
 \ nextgroup=ocamlTypeDefImpl
 

type-linter-test.ml

@@ -23,6 +23,8 @@
   type u = char
   type v = string
   type w = bytes
+  type abstract
+  type !+_ abstract'
 
   (* type expressions with arrows, tuples, 0-ary type constructors *)
   type t = t0 * t0 -> t0
@@ -139,7 +141,7 @@
   exception E
   exception E of int
   exception E : int -> exn
-  exception E' = E (* FIXME *)
+  exception E' = E
   (* local exceptions *)
   let _ = let exception E in ()
   let _ = let exception E of int * int in ()
@@ -165,6 +167,24 @@
   (* definition of an empty type *)
   type t = |
 
+  (* Constraints *)
+  type 'a foo := 'a bar
+
+(* RECURSION *)
+
+  type foo = bar
+  and bar
+  and baz = foo
+
+  ;;
+  let foo = 1
+  and bar = 2 in
+  ()
+
+  (* FIXME: 'and' part not matched by module decl (maybe matched by types decl ?). *)
+  module rec Foo : sig end = struct end
+  and Bar : sig end = struct end
+
 (* TYPE ANNOTATIONS *)
 
   (* annotations on let binders *)
@@ -317,6 +337,9 @@
     end
   end
 
+  (* FIXME: ':=' not recognized and RHS highlighted as constructor. *)
+  module Foo := Bar
+
 (* ATTRIBUTES *)
 
   exception[@my.attr "my payload"] E [@my.attr "my payload"]