Fix grammar for infix function signature

fix #13

Author: AndreasDahl

grammars/ocaml.cson

@@ -808,13 +808,13 @@
   'module-signature':
     'patterns': [
       {
-        'begin': '(val)\\s+([a-z_][a-zA-Z0-9_\']*)\\s*(:)'
+        'begin': '(val)\\s+(([a-z_][a-zA-Z0-9_\']*)|(\\(\\s*[=<>@^&+\\-*/$%|][|!$%&*+./:<=>?@^~-]*\\s*\\)))\\s*(:)'
         'beginCaptures':
           '1':
             'name': 'keyword.other.ocaml'
           '2':
             'name': 'entity.name.type.value-signature.ocaml'
-          '3':
+          '5':
             'name': 'punctuation.separator.type-constraint.ocaml'
         'end': '(?=\\b(type|val|external|class|module|end)\\b)|^\\s*$'
         'name': 'meta.module.signature.val.ocaml'

spec/ocaml.spec

@@ -50,3 +50,17 @@ begin fun x -> y end
 //  ^ keyword.operator.infix.integer.ocaml
    a|>b
 //  ^^ entity.name.function.infix.ocaml
+val test: a -> b
+// <- keyword.other.ocaml
+//  ^^^^ entity.name.type.value-signature.ocaml
+//      ^ punctuation.separator.type-constraint.ocaml
+//        ^ storage.type.ocaml
+//          ^^ punctuation.separator.function-return.ocaml
+//             ^ storage.type.ocaml
+val ( >> ): a -> b
+// <- keyword.other.ocaml
+//  ^^^^^^ entity.name.type.value-signature.ocaml
+//        ^ punctuation.separator.type-constraint.ocaml
+//          ^ storage.type.ocaml
+//            ^^ punctuation.separator.function-return.ocaml
+//               ^ storage.type.ocaml