Add support for modifiers/linearity annotations

Author: sheaf

CHANGELOG.md

@@ -9,6 +9,8 @@
 - Ensure highlighting of unicode forall syntax matches that of alphabetic forall syntax
   ([#175](https://github.com/JustusAdam/language-haskell/issues/175)).
 - Fix highlighting of empty quasi-quotations such as `[i||]`.
+- Support GHC 9.0 pragmas: `LinearTypes`, `QualifiedDo`, `LexicalNegation`.
+- Add support for [modifiers](https://github.com/ghc-proposals/ghc-proposals/pull/370), e.g. `id :: a %1 -> a`.
 
 ## 3.3.0 - 25.06.2020
 

syntaxes/haskell.YAML-tmLanguage

@@ -1456,14 +1456,15 @@ repository:
       - match: >-
           (?x)
             (?<![\p{Ll}_\p{Lu}\p{Lt}\p{Nd}\p{S}\p{P}&&[^(,;\[`{]])  # Disallow closing characters
-            (?:(~)|(!)|(-)|(\$)|(\$\$))
+            (?:(~)|(!)|(-)|(\$\$)|(\$)|(%))
             (?=[\p{Ll}_'\p{Lu}\p{Lt}\p{Nd}\(\{\[]) # Require opening character (non operator symbol)
         captures:
           '1': {name: keyword.operator.prefix.tilde.haskell}
           '2': {name: keyword.operator.prefix.bang.haskell}
           '3': {name: keyword.operator.prefix.minus.haskell}
-          '4': {name: keyword.operator.prefix.dollar.haskell}
-          '5': {name: keyword.operator.prefix.double-dollar.haskell}
+          '4': {name: keyword.operator.prefix.double-dollar.haskell}
+          '5': {name: keyword.operator.prefix.dollar.haskell}
+          '6': {name: keyword.operator.prefix.modifier.haskell}
   type_operator:
     patterns:
       # Symbolic type operator (optional promotion & qualification)

test/tests/LinearTypes.hs

@@ -0,0 +1,38 @@
+-- SYNTAX TEST "source.haskell" "LinearTypes"
+
+{-# LANGUAGE LinearTypes #-}
+--           ^^^^^^^^^^^ 	keyword.other.preprocessor.extension.haskell
+
+construct :: a %1 -> T1 a
+--             ^ keyword.operator.prefix.modifier.haskell
+construct x = MkT1 x
+
+deconstruct :: T1 a %1 -> a
+--                  ^ keyword.operator.prefix.modifier.haskell
+deconstruct (MkT1 x) = x
+
+data T2 a b c where
+    MkT2 :: a -> b %1 -> c %1 -> T2 a b c
+--                 ^       ^ keyword.operator.prefix.modifier.haskell
+
+data T3 a m where
+    MkT3 :: a %m -> T3 a m
+--            ^ keyword.operator.prefix.modifier.haskell
+
+
+f2 :: Int %Many -> Bool
+--        ^ keyword.operator.prefix.modifier.haskell
+f3 :: Int %m -> Bool
+--        ^ keyword.operator.prefix.modifier.haskell
+f4 :: Int %(m :: Multiplicity) -> Bool
+--        ^ keyword.operator.prefix.modifier.haskell
+
+map :: forall (m :: Multiplicity). (a %m -> b) -> [a] %m -> [b]
+--                                    ^               ^ keyword.operator.prefix.modifier.haskell
+
+foo :: a % b -> c % d
+--       ^        ^ - keyword.operator.prefix.modifier.haskell
+
+bar :: a %%b -> c %-% d
+--       ^^       ^ ^ - keyword.operator.prefix.modifier.haskell
+

test/tests/QualifiedDo.hs

@@ -0,0 +1,26 @@
+-- SYNTAX TEST "source.haskell" "QualifiedDo"
+
+{-# LANGUAGE QualifiedDo #-}
+--           ^^^^^^^^^^^ 	keyword.other.preprocessor.extension.haskell
+
+f :: IO ()
+f = do
+--  ^^ keyword.control.do.haskell
+  x <- runMAC $
+
+    MAC.mdo
+--  ^^^^ entity.name.namespace.haskell
+--      ^^^ keyword.control.mdo.haskell
+      d <- label "y"
+      box $
+
+        L.do
+--      ^^ entity.name.namespace.haskell
+--        ^^ keyword.control.do.haskell
+          r <- L.f d
+          L.g r
+          L.return r
+
+      MAC.return d
+
+  print x