More work on end codition for type signatures

Closes #89

CHANGELOG.md

@@ -22,7 +22,8 @@
   ([#104](https://github.com/JustusAdam/language-haskell/issues/104))
 - Pragmas are now case insensitive ([#81](https://github.com/JustusAdam/language-haskell/issues/81))
 - Fixed matcher for end of type annotations. Facilitates indented `module` blocks
-  ([#91](https://github.com/JustusAdam/language-haskell/issues/91)) 
+  ([#91](https://github.com/JustusAdam/language-haskell/issues/91)) and standalone deriving
+  ([#89](https://github.com/JustusAdam/language-haskell/issues/89))
 - Updated cabal grammar ([#93](https://github.com/JustusAdam/language-haskell/issues/93))
 - As a substantial internal change the grammar migratd to the YAML format, to make it easier to
   maintain and develop with.

syntaxes/haskell.YAML-tmLanguage

@@ -82,11 +82,17 @@ patterns:
           - {include: '#type_signature'}
     patterns:
       - {include: '#type_signature'}
-    end: '(?=(<\-)|(^(\1)?[^\s]|}))'
-  - begin: '\b(instance)(\b(?!''))'
+    end: | 
+      (?x)
+        (?=(<\-)|})
+        | ^(?!\1\s+\S|\s*$)    # at least one, no-further indented, non-whitespace character. I.e. a same-level declaration/implementation
+  - begin: '^(\s*)\b(instance)(\b(?!''))'
     beginCaptures:
-      '1': {name: keyword.other.haskell}
-    end: '(\b(where)(\b(?!''))|(?=^\S))'
+      '2': {name: keyword.other.haskell}
+    end: |
+      (?x)
+        \b(where)\b(?!')
+        | ^(?!\1\s+\S|\s*$)    # at least one, no-further indented, non-whitespace character. I.e. a same-level declaration/implementation
     endCaptures:
       '1': {name: keyword.other.haskell}
     name: meta.declaration.instance.haskell
@@ -110,6 +116,11 @@ patterns:
     name: meta.deriving.haskell
     patterns:
       - {include: '#derivings'}
+  - match: '\b(deriving) (instance)\b(.*)$'
+    captures:
+      '1': {name: keyword.other.haskell}
+      '2': {name: keyword.other.haskell}
+      '3': {patterns: [{include: '#type_signature'}]}
   - match: >-
       (deriving)\s+([\p{Lu}\p{Lt}][\p{Ll}_\p{Lu}\p{Lt}\p{Nd}']*)
     captures:
@@ -118,8 +129,7 @@ patterns:
     name: meta.deriving.haskell
   - match: >-
       (?x)\b
-        ( deriving
-        | where
+        ( where
         | type([\\t ]+(family|role))
         | let
         | in
@@ -191,7 +201,7 @@ patterns:
           (<\-)           # we are the left side of a `x :: Type <- expr` bind statement
           | }             # A block closed? Maybe this should also include `;`, because non-indentation based `do`
         )
-        | ^(?!\1[^\s])    # at least one, no-further indented, non-whitespace character. I.e. a same-level declaration/implementation
+        | ^(?!\1\s+\S|\s*$)    # at least one, no-further indented, non-whitespace character. I.e. a same-level declaration/implementation
   - {include: '#data_constructor'}
   - {include: '#qualifier'}
   - {include: '#comments'}

test/syntax-examples/test.hs

@@ -26,6 +26,10 @@ module M
     myFoo :: Foo
     myFoo = foo
 
+
+    deriving instance SomeClass => Eq a
+    deriving instance Ord a => Ord (Expr a)
+
 class Foo x where
     myFoo :: Foo
 
@@ -73,7 +77,7 @@ type T a =
     Constr 
     a 
     Int
->
+
 -- Multi line type alias with infix constructors
 
 type UserApi = "users" :> Body '[JSON]