Testsuite error message changes

testsuite/tests/deSugar/should_compile/T2431.stderr

@@ -2,7 +2,7 @@
 ==================== Tidy Core ====================
 Result size of Tidy Core = {terms: 8, types: 19, coercions: 1}
 
-T2431.$WRefl [InlPrag=INLINE] :: forall a. a T2431.:~: a
+T2431.$WRefl [InlPrag=INLINE] :: forall a. a :~: a
 [GblId[DataConWrapper],
  Caf=NoCafRefs,
  Str=DmdType,
@@ -12,12 +12,9 @@ T2431.$WRefl [InlPrag=INLINE] :: forall a. a T2431.:~: a
          Tmpl= \ (@ a) -> T2431.Refl @ a @ a @~ <a>_N}]
 T2431.$WRefl = \ (@ a) -> T2431.Refl @ a @ a @~ <a>_N
 
-T2431.absurd
-  :: forall a. GHC.Types.Int T2431.:~: GHC.Types.Bool -> a
+absurd :: forall a. Int :~: Bool -> a
 [GblId, Arity=1, Caf=NoCafRefs, Str=DmdType <L,U>b]
-T2431.absurd =
-  \ (@ a) (x :: GHC.Types.Int T2431.:~: GHC.Types.Bool) ->
-    case x of _ [Occ=Dead] { }
+absurd = \ (@ a) (x :: Int :~: Bool) -> case x of _ [Occ=Dead] { }
 
 
 

testsuite/tests/deriving/should_fail/T9071.stderr

@@ -2,7 +2,7 @@
 [2 of 2] Compiling T9071            ( T9071.hs, T9071.o )
 
 T9071.hs:7:37:
-    No instance for (Functor K)
+    No instance for (Functor Mu)
       arising from the first field of ‘F’ (type ‘Mu (K a)’)
     Possible fix:
       use a standalone 'deriving instance' declaration,

testsuite/tests/deriving/should_fail/T9071_2.stderr

 
 T9071_2.hs:7:40:
-    No instance for (Functor Mu)
+    No instance for (Functor K1)
       arising from the first field of ‘F1’ (type ‘Mu (K1 a)’)
     Possible fix:
       use a standalone 'deriving instance' declaration,

testsuite/tests/gadt/T3169.stderr

 
 T3169.hs:13:22:
-    Could not deduce (elt ~ Map b elt)
-    from the context (Key a, Key b)
-      bound by the instance declaration at T3169.hs:10:10-36
+    Couldn't match type ‘elt’ with ‘Map b elt’
       ‘elt’ is a rigid type variable bound by
             the type signature for
               lookup :: (a, b) -> Map (a, b) elt -> Maybe elt

testsuite/tests/gadt/T7293.stderr

 
 T7293.hs:24:5:
-    Couldn't match type ‘'False’ with ‘'True’
+    Couldn't match type ‘'True’ with ‘'False’
     Inaccessible code in
       a pattern with constructor
         Nil :: forall a. Vec a 'Zero,

testsuite/tests/gadt/T7294.stderr

 
 T7294.hs:25:5: Warning:
-    Couldn't match type ‘'False’ with ‘'True’
+    Couldn't match type ‘'True’ with ‘'False’
     Inaccessible code in
       a pattern with constructor
         Nil :: forall a. Vec a 'Zero,

testsuite/tests/gadt/gadt21.stderr

-
-gadt21.hs:21:60:
-    Could not deduce (Ord a1) arising from a use of ‘f’
-    from the context (a ~ Set a1)
-      bound by a pattern with constructor
-                 TypeSet :: forall a. Type a -> Type (Set a),
-               in an equation for ‘withOrdDynExpr’
-      at gadt21.hs:21:35-43
-    Possible fix:
-      add (Ord a1) to the context of
-        the data constructor ‘TypeSet’
-        or the data constructor ‘DynExpr’
-        or the type signature for
-             withOrdDynExpr :: DynExpr
-                               -> (forall a. Ord a => Expr a -> b) -> Maybe b
-    In the first argument of ‘Just’, namely ‘(f e)’
-    In the expression: Just (f e)
-    In an equation for ‘withOrdDynExpr’:
-        withOrdDynExpr (DynExpr e@(Const (TypeSet _) _)) f = Just (f e)
+
+gadt21.hs:21:60:
+    Could not deduce (Ord a1) arising from a use of ‘f’
+    from the context (a ~ Set a1)
+      bound by a pattern with constructor
+                 TypeSet :: forall a. Type a -> Type (Set a),
+               in an equation for ‘withOrdDynExpr’
+      at gadt21.hs:21:35-43
+    Possible fix:
+      add (Ord a1) to the context of the data constructor ‘TypeSet’
+    In the first argument of ‘Just’, namely ‘(f e)’
+    In the expression: Just (f e)
+    In an equation for ‘withOrdDynExpr’:
+        withOrdDynExpr (DynExpr e@(Const (TypeSet _) _)) f = Just (f e)

testsuite/tests/ghc-api/apirecomp001/apirecomp001.stderr

@@ -3,14 +3,14 @@ B.hs:4:1: Warning:
     Top-level binding with no type signature:
       answer_to_live_the_universe_and_everything :: Int
 
-B.hs:5:13: Warning:
+B.hs:5:12: Warning:
     Defaulting the following constraint(s) to type ‘Integer’
-      (Num a0) arising from the literal ‘1’ at B.hs:5:13
       (Enum a0)
         arising from the arithmetic sequence ‘1 .. 23 * 2’ at B.hs:5:12-20
-    In the expression: 1
+      (Num a0) arising from the literal ‘1’ at B.hs:5:13
     In the first argument of ‘length’, namely ‘[1 .. 23 * 2]’
     In the first argument of ‘(-)’, namely ‘length [1 .. 23 * 2]’
+    In the expression: length [1 .. 23 * 2] - 4
 
 A.hs:7:1: Warning:
     Top-level binding with no type signature: main :: IO ()
@@ -19,14 +19,14 @@ B.hs:4:1: Warning:
     Top-level binding with no type signature:
       answer_to_live_the_universe_and_everything :: Int
 
-B.hs:5:13: Warning:
+B.hs:5:12: Warning:
     Defaulting the following constraint(s) to type ‘Integer’
-      (Num a0) arising from the literal ‘1’ at B.hs:5:13
       (Enum a0)
         arising from the arithmetic sequence ‘1 .. 23 * 2’ at B.hs:5:12-20
-    In the expression: 1
+      (Num a0) arising from the literal ‘1’ at B.hs:5:13
     In the first argument of ‘length’, namely ‘[1 .. 23 * 2]’
     In the first argument of ‘(-)’, namely ‘length [1 .. 23 * 2]’
+    In the expression: length [1 .. 23 * 2] - 4
 
 A.hs:7:1: Warning:
     Top-level binding with no type signature: main :: IO ()

testsuite/tests/ghci.debugger/scripts/break026.stdout

-Stopped at break026.hs:(5,1)-(7,35)
-_result :: t = _
-Stopped at break026.hs:5:16-22
-_result :: Integer = _
-c :: Integer = 0
-go :: Integer -> [t1] -> Integer = _
-xs :: [t1] = _
-Stopped at break026.hs:(6,9)-(7,35)
-_result :: t = _
-f :: t -> t1 -> t = _
-Stopped at break026.hs:7:23-35
-_result :: Integer = _
-c :: Integer = 0
-f :: Integer -> Integer -> Integer = _
-x :: Integer = 1
-xs :: [Integer] = _
-Stopped at break026.hs:(6,9)-(7,35)
-_result :: t = _
-f :: t -> t1 -> t = _
-Stopped at break026.hs:7:23-35
-_result :: t = _
-c :: t = _
-f :: t -> Integer -> t = _
-x :: Integer = 2
-xs :: [Integer] = _
-c = 1
-Stopped at break026.hs:(5,1)-(7,35)
-_result :: t = _
-Stopped at break026.hs:5:16-22
-_result :: Integer = _
-c :: Integer = 0
-go :: Integer -> [t1] -> Integer = _
-xs :: [t1] = _
-Stopped at break026.hs:(6,9)-(7,35)
-_result :: t = _
-f :: t -> t1 -> t = _
-Stopped at break026.hs:7:23-35
-_result :: Integer = _
-c :: Integer = 0
-f :: Integer -> Integer -> Integer = _
-x :: Integer = 1
-xs :: [Integer] = _
-Stopped at break026.hs:(6,9)-(7,35)
-_result :: t = _
-f :: t -> t1 -> t = _
-Stopped at break026.hs:7:23-35
-_result :: t = _
-c :: t = _
-f :: t -> Integer -> t = _
-x :: Integer = 2
-xs :: [Integer] = _
-Stopped at break026.hs:7:27-31
-_result :: Integer = _
-c :: Integer = 0
-f :: Integer -> Integer -> Integer = _
-x :: Integer = 1
-()
-1
+Stopped at break026.hs:(5,1)-(7,35)
+_result :: t1 = _
+Stopped at break026.hs:5:16-22
+_result :: Integer = _
+c :: Integer = 0
+go :: Integer -> [t] -> Integer = _
+xs :: [t] = _
+Stopped at break026.hs:(6,9)-(7,35)
+_result :: t1 = _
+f :: t1 -> t -> t1 = _
+Stopped at break026.hs:7:23-35
+_result :: Integer = _
+c :: Integer = 0
+f :: Integer -> Integer -> Integer = _
+x :: Integer = 1
+xs :: [Integer] = _
+Stopped at break026.hs:(6,9)-(7,35)
+_result :: t1 = _
+f :: t1 -> t -> t1 = _
+Stopped at break026.hs:7:23-35
+_result :: t1 = _
+c :: t1 = _
+f :: t1 -> Integer -> t1 = _
+x :: Integer = 2
+xs :: [Integer] = _
+c = 1
+Stopped at break026.hs:(5,1)-(7,35)
+_result :: t1 = _
+Stopped at break026.hs:5:16-22
+_result :: Integer = _
+c :: Integer = 0
+go :: Integer -> [t] -> Integer = _
+xs :: [t] = _
+Stopped at break026.hs:(6,9)-(7,35)
+_result :: t1 = _
+f :: t1 -> t -> t1 = _
+Stopped at break026.hs:7:23-35
+_result :: Integer = _
+c :: Integer = 0
+f :: Integer -> Integer -> Integer = _
+x :: Integer = 1
+xs :: [Integer] = _
+Stopped at break026.hs:(6,9)-(7,35)
+_result :: t1 = _
+f :: t1 -> t -> t1 = _
+Stopped at break026.hs:7:23-35
+_result :: t1 = _
+c :: t1 = _
+f :: t1 -> Integer -> t1 = _
+x :: Integer = 2
+xs :: [Integer] = _
+Stopped at break026.hs:7:27-31
+_result :: Integer = _
+c :: Integer = 0
+f :: Integer -> Integer -> Integer = _
+x :: Integer = 1
+()
+1

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

@@ -41,6 +41,14 @@ class Mergeable a b where
     type MergerType a b
     merger :: a -> b -> MergerType a b
 
+{-
+merge ::
+    forall a b.
+    (Merger (MergerType a b), Mergeable a b,
+     UnmergedLeft (MergerType a b) ~ a,
+     UnmergedRight (MergerType a b) ~ b) =>
+    a -> b -> Merged (MergerType a b)
+-}
 merge x y = mkMerge (merger x y) x y
 
 data TakeRight a
@@ -117,4 +125,4 @@ instance
     type Merged (RightHeadFirst h1 t1 h2 t2) = h2 :* Merged (MergerType (h1 :* t1) t2)
     type UnmergedLeft (RightHeadFirst h1 t1 h2 t2) = h1 :* t1
     type UnmergedRight (RightHeadFirst h1 t1 h2 t2) = h2 :* t2
-    mkMerge _ (h1 :* t1) (h2 :* t2) = h2 :* mkMerge (merger (h1 :* t1) t2) (h1 :* t1) t2
\ No newline at end of file
+    mkMerge _ (h1 :* t1) (h2 :* t2) = h2 :* mkMerge (merger (h1 :* t1) t2) (h1 :* t1) t2

testsuite/tests/indexed-types/should_compile/PushInAsGivens.stderr

+ 
\ No newline at end of file

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

@@ -8,7 +8,7 @@ type family F a
 
 bar y = let foo :: (F Int ~ [a]) => a -> Int 
             foo x = length [x,y]  
-      in (y,foo y)
+        in (y,foo y)
 
 
 -- This example demonstrates why we need to push in 
@@ -20,5 +20,12 @@ bar y = let foo :: (F Int ~ [a]) => a -> Int
 -- Given/Solved, it will be discarded when we meet the given (F Int ~ [a]) and 
 -- we will not be able to solve the implication constraint.
 
+-- Oct 14: actually this example is _really_ strange, and doesn't illustrate
+-- the real issue in Trac #4935, for which there is a separate test
+--
+-- The example here requires us to infer a type
+--   bar :: F Int ~ [a] => ...
+-- which is a strange type to quantify over; better to complain about
+-- having no instance for F Int.
 
 

testsuite/tests/indexed-types/should_compile/PushedInAsGivens.stderr

+
+PushedInAsGivens.hs:10:31:
+    Couldn't match expected type ‘a1’ with actual type ‘a’
+      because type variable ‘a1’ would escape its scope
+    This (rigid, skolem) type variable is bound by
+      the type signature for foo :: (F Int ~ [a1]) => a1 -> Int
+      at PushedInAsGivens.hs:9:20-44
+    Relevant bindings include
+      x :: a1 (bound at PushedInAsGivens.hs:10:17)
+      foo :: a1 -> Int (bound at PushedInAsGivens.hs:10:13)
+      y :: a (bound at PushedInAsGivens.hs:9:5)
+      bar :: a -> (a, Int) (bound at PushedInAsGivens.hs:9:1)
+    In the expression: y
+    In the first argument of ‘length’, namely ‘[x, y]’
+
+PushedInAsGivens.hs:11:15:
+    Couldn't match expected type ‘[a]’ with actual type ‘F Int’
+    Relevant bindings include
+      y :: a (bound at PushedInAsGivens.hs:9:5)
+      bar :: a -> (a, Int) (bound at PushedInAsGivens.hs:9:1)
+    In the expression: foo y
+    In the expression: (y, foo y)
+    In the expression:
+      let
+        foo :: (F Int ~ [a]) => a -> Int
+        foo x = length [...]
+      in (y, foo y)

testsuite/tests/indexed-types/should_compile/Simple13.hs

@@ -16,3 +16,33 @@ mkf p = undefined
 foo :: a ~ [F a] => a -> a
 foo p = same p (mkf p)
 
+{- p :: a
+
+  [G] g : a ~ [F a]
+  [W] w : a ~ [F a]
+
+---> 
+  g' = g;[x]                g'=aq4
+  [G] g'  : a ~ [fsk]       g=aqW
+  [W] x : F a ~ fsk         x=aq3
+
+  [W] w : a ~ [F a]
+
+  --> subst a
+       x = F g' ; x2
+   [W] x2 : F fsk ~ fsk     x2=aq5
+
+  -->  (subst a)
+      w = g' ; w2
+  [W] w2 : [fsk] ~ [F a]
+
+  --> decompose 
+       w2 = [w3]
+   [W] w3 : fsk ~ F a
+
+
+
+cycle is
+   aq3 = Sym (F aq4) ; aq5    x = Sym (F g') ; x2
+   aq4 = apw ; aq3            g' = 
+-}

testsuite/tests/indexed-types/should_compile/Simple8.hs

@@ -8,7 +8,7 @@ type family F a
 -- works if one of the duplicates is removed.
 
 type instance F () = ()
-type instance F () = ()
+-- type instance F () = ()
 
 foo :: F () -> ()
 foo x = x

testsuite/tests/indexed-types/should_compile/T3017.stderr

 TYPE SIGNATURES
   emptyL :: forall a. ListColl a
   test2 ::
-    forall c t t1. (Coll c, Num t1, Num t, Elem c ~ (t, t1)) => c -> c
+    forall c t t1. (Num t, Num t1, Coll c, Elem c ~ (t, t1)) => c -> c
 TYPE CONSTRUCTORS
   class Coll c where
     type family Elem c :: * open

testsuite/tests/indexed-types/should_compile/T3208b.stderr

 
 T3208b.hs:15:10:
-    Could not deduce (STerm o0 ~ STerm a)
+    Could not deduce (STerm o0 ~ OTerm o0)
     from the context (OTerm a ~ STerm a, OBJECT a, SUBST a)
       bound by the type signature for
                  fce' :: (OTerm a ~ STerm a, OBJECT a, SUBST a) => a -> c
       at T3208b.hs:14:9-56
-    NB: ‘STerm’ is a type function, and may not be injective
     The type variable ‘o0’ is ambiguous
-    Expected type: STerm o0
-      Actual type: OTerm o0
-    Relevant bindings include
-      f :: a (bound at T3208b.hs:15:6)
-      fce' :: a -> c (bound at T3208b.hs:15:1)
     In the expression: fce (apply f)
     In an equation for ‘fce'’: fce' f = fce (apply f)
 
 T3208b.hs:15:15:
-    Could not deduce (OTerm o0 ~ STerm a)
+    Could not deduce (OTerm o0 ~ OTerm a)
     from the context (OTerm a ~ STerm a, OBJECT a, SUBST a)
       bound by the type signature for
                  fce' :: (OTerm a ~ STerm a, OBJECT a, SUBST a) => a -> c
       at T3208b.hs:14:9-56
+    NB: ‘OTerm’ is a type function, and may not be injective
     The type variable ‘o0’ is ambiguous
+    Expected type: STerm a
+      Actual type: OTerm o0
     Relevant bindings include
       f :: a (bound at T3208b.hs:15:6)
       fce' :: a -> c (bound at T3208b.hs:15:1)

testsuite/tests/indexed-types/should_compile/T3826.hs

@@ -6,10 +6,56 @@ class C a where
   type E a
   c :: E a -> a -> a
 
-data T a = T a
+data T a = MkT a
+-- MkT :: a -> T a
 
-instance C (T a) where
-  type E (T a) = a
-  c x (T _) = T x
+instance C (T b) where
+  type E (T b) = b
+  c x (MkT _) = MkT x
+
+
+f t@(MkT x) = c x t
+
+{- c :: E alpha -> alpha -> alpha
+   t :: T beta
+   x :: beta
+   f :: T beta -> gamma
+
+
+   [W] C alpha
+   [W] E alpha ~ beta
+   [W] alpha ~ T beta
+   [W] gamma ~ alpha   
+
+--->                       beta = t_aqf  alpha = t_aqg
+   alpha := T beta
+   gamma := alpha
+
+   [W] E (T beta) ~ beta
+
+-->
+   [W] ufsk ~ beta      
+   [W] E (T beta) ~ ufsk
+
+--> (swap and subst)
+   beta := ufsk
+   [W] x : E (T ufsk) ~ ufsk   (do not rewrite RHS)
+
+take a step   ax: E (T beta) ~ beta
+
+-->
+   [W] ufsk 
+--------------------------
+ But what about this?
+--------------------------
+
+axiom F [a] = F [a]
+
+   x : F [a] ~ fsk
+step
+   ax : F [a] ~ F [a] 
+flatten
+   ax ; x : F [a] ~ fsk
+   x = ax ; x       Oh dear!
+-}
 
-f t@(T x) = c x t

testsuite/tests/indexed-types/should_compile/T4494.hs

@@ -10,3 +10,23 @@ bar = error "urk"
 
 call :: F Bool -> Int
 call x = bar (\_ -> x) (undefined :: H (F Bool))
+
+{-
+  [W] H (F Bool) ~ H alpha
+  [W] alpha ~ F Bool
+-->
+  F Bool  ~ fuv0
+  H fuv0  ~ fuv1
+  H alpha ~ fuv2
+
+  fuv1 ~ fuv2
+  alpha ~ fuv0
+
+flatten
+~~~~~~~
+fuv0 := alpha
+fuv1 := fuv2
+
+alpha := F Bool
+-}
+

testsuite/tests/indexed-types/should_compile/T7804.hs

@@ -8,3 +8,15 @@ data Proxy a = P
 
 sDFMap :: (forall a. Proxy f -> Proxy a -> Proxy (F f a)) -> Int
 sDFMap _ = 3
+
+
+{-
+flat cache
+ [G] F f_aqh aqj ~ fsk_aqp
+ [G] F f_aqg aqj ~ fsk_aqq
+
+ [W] aqk : f_aqh[2] ~ f_aqg
+ [w] aql : fsk_aqp ~ fsk_aqq
+
+ [G] F f_agh a_aqj ~ F f_aqg
+-}
\ No newline at end of file

testsuite/tests/indexed-types/should_compile/all.T

@@ -170,7 +170,7 @@ test('T4981-V2', normal, compile, [''])
 test('T4981-V3', normal, compile, [''])
 
 test('T5002', normal, compile, [''])
-test('PushedInAsGivens', normal, compile, [''])
+test('PushedInAsGivens', normal, compile_fail, [''])
 
 # Superclass equalities
 test('T4338', normal, compile, [''])

testsuite/tests/indexed-types/should_fail/ExtraTcsUntch.hs

 {-# LANGUAGE TypeFamilies, FunctionalDependencies, FlexibleContexts, GADTs, ScopedTypeVariables #-}
 
-module ExtraTcsUntch where 
+module ExtraTcsUntch where
 
 
-class C x y | x -> y where 
+class C x y | x -> y where
  op :: x -> y -> ()
 
 instance C [a] [a]
@@ -13,22 +13,24 @@ type family F a :: *
 h :: F Int -> ()
 h = undefined
 
-data TEx where 
-  TEx :: a -> TEx 
+data TEx where
+  TEx :: a -> TEx
 
 
 
-f x = 
+f x =
     let g1 :: forall b. b -> ()
         g1 _ = h [x]
+
         g2 z = case z of TEx y -> (h [[undefined]], op x [y])
+
     in (g1 '3', g2 undefined)
 
 
-{- This example comes from Note [Extra TcS Untouchables] in TcSimplify. It demonstrates 
+{- This example comes from Note [Extra TcS Untouchables] in TcSimplify. It demonstrates
    why when floating equalities out of an implication constraint we must record the free
    variables of the equalities as untouchables. With GHC 7.4.1 this program gives a Core
-   Lint error because of an existential escaping. 
+   Lint error because of an existential escaping.
 
     assuming x:beta
 
@@ -39,16 +41,21 @@ f x =
 
 
 
-   
+
 {- Assume x:beta
-   From g1 we get    (forall b.  F Int ~ [beta])
-   From g2 we get    (forall c. 0 => F Int ~ [[alpha]] /\ C beta [c])
-
-Floating we get
-   F Int ~ [beta], F Int ~ [[alpha]], alpha ~ alpha', forall c. C beta [c]
-=  { alpha := alpha' }
-=  beta ~ [alpha'], F Int ~ [[alpha']], forall c. C beta [c]
-=  { beta := [alpha']
-   F Int ~ [[alpha']], forall c. C [alpha'] [c]
-=  F Int ~ [[alpha']], forall c. (C [alpha'] [c], alpha' ~ c)
+   From g1 we get [W]    (forall b.  F Int ~ [beta])
+
+   From g2 we get [W]   (forall c. 0 => F Int ~ [[alpha]] /\ C beta [c])