Whitespace forward compatibility for proposal #229

GHC Proposal #229 changes the lexical rules of Haskell, which may
require slight whitespace adjustments in certain cases.

This patch changes formatting in a few places in GHC and its testsuite
in a way that enables it to compile under the proposed rules.

compiler/typecheck/TcRnExports.hs

@@ -269,7 +269,7 @@ exports_from_avail (Just (dL->L _ rdr_items)) rdr_env imports this_mod
 
     -- See Note [Avails of associated data families]
     expand_tyty_gre :: GlobalRdrElt -> [GlobalRdrElt]
-    expand_tyty_gre (gre @ GRE { gre_name = me, gre_par = ParentIs p })
+    expand_tyty_gre (gre@GRE { gre_name = me, gre_par = ParentIs p })
       | isTyConName p, isTyConName me = [gre, gre{ gre_par = NoParent }]
     expand_tyty_gre gre = [gre]
 

compiler/utils/Dominators.hs

@@ -364,11 +364,11 @@ domM = fetch domE
 rootM :: Dom s Node
 rootM = gets rootE
 succsM :: Node -> Dom s [Node]
-succsM i = gets (IS.toList . (!i) . succE)
+succsM i = gets (IS.toList . (! i) . succE)
 predsM :: Node -> Dom s [Node]
-predsM i = gets (IS.toList . (!i) . predE)
+predsM i = gets (IS.toList . (! i) . predE)
 bucketM :: Node -> Dom s [Node]
-bucketM i = gets (IS.toList . (!i) . bucketE)
+bucketM i = gets (IS.toList . (! i) . bucketE)
 sizeM :: Node -> Dom s Int
 sizeM = fetch sizeE
 sdnoM :: Node -> Dom s Int

testsuite/tests/deSugar/should_compile/ds020.hs

@@ -11,7 +11,7 @@ a ~(~[],~[],~[]) = []
 b ~(x:xs:ys)      = []
 b ~(~x: ~xs: ~ys) = []
 
-c ~x ~ _ ~11111 ~3.14159265 = x
+c ~x ~_ ~11111 ~3.14159265 = x
 
 d 11        = 4
 d 12        = 3

testsuite/tests/determinism/determ017/A.hs

@@ -85,7 +85,7 @@ instance MonadFail Identity where
     fail = error "Identity(fail)"
 
 newtype Trampoline m s r = Trampoline {bounce :: m (TrampolineState m s r)}
-data TrampolineState m s r = Done r | Suspend! (s (Trampoline m s r))
+data TrampolineState m s r = Done r | Suspend !(s (Trampoline m s r))
 
 instance (Monad m, Functor s) => Functor (Trampoline m s) where
   fmap = liftM
@@ -103,11 +103,11 @@ instance (Monad m, Functor s) => Monad (Trampoline m s) where
 instance (MonadFail m, Functor s) => MonadFail (Trampoline m s) where
    fail = error "Trampoline(fail)"
 
-data Yield x y = Yield! x y
+data Yield x y = Yield !x y
 instance Functor (Yield x) where
    fmap f (Yield x y) = trace "fmap yield" $ Yield x (f y)
 
-data Await x y = Await! (x -> y)
+data Await x y = Await !(x -> y)
 instance Functor (Await x) where
    fmap f (Await g) = trace "fmap await" $ Await (f . g)
 

testsuite/tests/indexed-types/should_compile/T3787.hs

@@ -76,7 +76,7 @@ data TrampolineState s m r =
    -- | Trampoline computation is finished with final value /r/.
    Done r
    -- | Computation is suspended, its remainder is embedded in the functor /s/.
- | Suspend! (s (Trampoline s m r))
+ | Suspend !(s (Trampoline s m r))
 
 instance (Functor s, Monad m) => Functor (Trampoline s m) where
    fmap = liftM
@@ -101,11 +101,11 @@ instance (Functor s, ParallelizableMonad m) => ParallelizableMonad (Trampoline s
 instance Functor s => MonadTrans (Trampoline s) where
    lift = Trampoline . liftM Done
 
-data Yield x y = Yield! x y
+data Yield x y = Yield !x y
 instance Functor (Yield x) where
    fmap f (Yield x y) = Yield x (f y)
 
-data Await x y = Await! (x -> y)
+data Await x y = Await !(x -> y)
 instance Functor (Await x) where
    fmap f (Await g) = Await (f . g)
 

testsuite/tests/module/mod70.hs

 -- !!! Illegal ~ in expression
 module M where
-f x = x~1
+f x = x ~1

testsuite/tests/module/mod70.stderr

 
-mod70.hs:3:8: error: Pattern syntax in expression context: ~1
+mod70.hs:3:9: error: Pattern syntax in expression context: ~1

testsuite/tests/parser/should_compile/T13600b.hs

 module T13600b where
 
-f !(Just x) = f !! x
-f !y = head f
+f ! (Just x) = f !! x
+f ! y = head f
 
 x = [1,2,3] ! Just 1
   where
-    f !(Just x) = f !! x
-    f !y = head f
+    f ! (Just x) = f !! x
+    f ! y = head f

testsuite/tests/parser/should_compile/T13600b.stderr

-
-T13600b.hs:3:3: warning: [-Wmissing-space-after-bang (in -Wdefault)]
-      Did you forget to enable BangPatterns?
-      If you mean to bind (!) then perhaps you want
-      to add a space after the bang for clarity.
-
-T13600b.hs:4:3: warning: [-Wmissing-space-after-bang (in -Wdefault)]
-      Did you forget to enable BangPatterns?
-      If you mean to bind (!) then perhaps you want
-      to add a space after the bang for clarity.
-
-T13600b.hs:8:7: warning: [-Wmissing-space-after-bang (in -Wdefault)]
-      Did you forget to enable BangPatterns?
-      If you mean to bind (!) then perhaps you want
-      to add a space after the bang for clarity.
-
-T13600b.hs:9:7: warning: [-Wmissing-space-after-bang (in -Wdefault)]
-      Did you forget to enable BangPatterns?
-      If you mean to bind (!) then perhaps you want
-      to add a space after the bang for clarity.

testsuite/tests/programs/strict_anns/Main.hs

@@ -3,9 +3,9 @@
 
 module Main where
 
-data Foo1 = Crunch1 ! Int ! Int Int deriving( Show )
+data Foo1 = Crunch1 !Int !Int Int deriving( Show )
 
-data Foo2 = Crunch2 ! Int Int Int   deriving( Show )
+data Foo2 = Crunch2 !Int Int Int   deriving( Show )
 
 main = do
         print (Crunch1 (1+1) (2+2) (3+3))

testsuite/tests/rename/should_fail/rnfail016.hs

@@ -3,5 +3,5 @@ module ShouldFail where
 
 -- !!! Pattern syntax in expressions
 
-f x = x @ x
+f x = x@x
 

testsuite/tests/simplCore/should_run/T3591.hs

@@ -83,7 +83,7 @@ instance Monad Identity where
     m >>= k  = k (runIdentity m)
 
 newtype Trampoline m s r = Trampoline {bounce :: m (TrampolineState m s r)}
-data TrampolineState m s r = Done r | Suspend! (s (Trampoline m s r))
+data TrampolineState m s r = Done r | Suspend !(s (Trampoline m s r))
 
 instance (Monad m, Functor s) => Functor (Trampoline m s) where
   fmap = liftM
@@ -101,11 +101,11 @@ instance (Monad m, Functor s) => Monad (Trampoline m s) where
 instance (Monad m, Functor s) => MonadFail (Trampoline m s) where
   fail = error
 
-data Yield x y = Yield! x y
+data Yield x y = Yield !x y
 instance Functor (Yield x) where
    fmap f (Yield x y) = trace "fmap yield" $ Yield x (f y)
 
-data Await x y = Await! (x -> y)
+data Await x y = Await !(x -> y)
 instance Functor (Await x) where
    fmap f (Await g) = trace "fmap await" $ Await (f . g)
 

testsuite/tests/typecheck/should_fail/T11313.hs

@@ -2,6 +2,6 @@
 
 module T11313 where
 
-x = fmap @ (*)
+x = fmap @(*)
 
 -- test error message output, which was quite silly before

testsuite/tests/typecheck/should_fail/T11313.stderr

 
-T11313.hs:5:13: error:
+T11313.hs:5:12: error:
     • Expected kind ‘* -> *’, but ‘*’ has kind ‘*’
     • In the type ‘(*)’
       In the expression: fmap @(*)

testsuite/tests/typecheck/should_fail/T12529.hs

@@ -2,4 +2,4 @@
 
 module T12529 where
 
-f = p @ Int
+f = p @Int

testsuite/tests/typecheck/should_fail/tcfail112.hs

@@ -4,7 +4,7 @@
 
 module ShouldFail where
 
-data S = S { x::Int, y:: ! Int }
+data S = S { x::Int, y:: !Int }
 data T = T Int !Int
 data U = U Int  Int