Always display inferred variables using braces

We now always show "forall {a}. T" for inferred variables,
previously this was controlled by -fprint-explicit-foralls.

This implements part 1 of https://github.com/ghc-proposals/ghc-proposals/pull/179.

Part of GHC ticket #16320.

Furthermore, when printing a levity restriction error, we now display
the HsWrap of the expression. This lets users see the full elaboration with
-fprint-typechecker-elaboration (see also #17670)

3 files changed, 15 insertions, 15 deletions

diff --git a/testsuite/tests/patsyn/should_compile/T11213.stderr b/testsuite/tests/patsyn/should_compile/T11213.stderr
index 212e3e9334..8d65044ec6 100644
--- a/testsuite/tests/patsyn/should_compile/T11213.stderr
+++ b/testsuite/tests/patsyn/should_compile/T11213.stderr
@@ -4,48 +4,48 @@ T11213.hs:19:1: warning: [-Wmissing-pattern-synonym-signatures (in -Wall)]
 
 T11213.hs:20:1: warning: [-Wmissing-pattern-synonym-signatures (in -Wall)]
     Pattern synonym with no type signature:
-      pattern Pe :: () => forall a. a -> Ex
+      pattern Pe :: () => forall {a}. a -> Ex
 
 T11213.hs:21:1: warning: [-Wmissing-pattern-synonym-signatures (in -Wall)]
     Pattern synonym with no type signature:
-      pattern Pu :: forall p. p -> p
+      pattern Pu :: forall {p}. p -> p
 
 T11213.hs:22:1: warning: [-Wmissing-pattern-synonym-signatures (in -Wall)]
     Pattern synonym with no type signature:
-      pattern Pue :: forall a. () => forall a1. a -> a1 -> (a, Ex)
+      pattern Pue :: forall {a}. () => forall {a1}. a -> a1 -> (a, Ex)
 
 T11213.hs:23:1: warning: [-Wmissing-pattern-synonym-signatures (in -Wall)]
     Pattern synonym with no type signature:
-      pattern Pur :: forall a. (Eq a, Num a) => a -> [a]
+      pattern Pur :: forall {a}. (Eq a, Num a) => a -> [a]
 
 T11213.hs:24:1: warning: [-Wmissing-pattern-synonym-signatures (in -Wall)]
     Pattern synonym with no type signature:
-      pattern Purp :: forall a1 a2.
+      pattern Purp :: forall {a1} {a2}.
                       (Eq a1, Num a1) =>
                       Show a2 => a1 -> a2 -> ([a1], UnivProv a2)
 
 T11213.hs:25:1: warning: [-Wmissing-pattern-synonym-signatures (in -Wall)]
     Pattern synonym with no type signature:
-      pattern Pure :: forall a.
+      pattern Pure :: forall {a}.
                       (Eq a, Num a) =>
-                      forall a1. a -> a1 -> ([a], Ex)
+                      forall {a1}. a -> a1 -> ([a], Ex)
 
 T11213.hs:26:1: warning: [-Wmissing-pattern-synonym-signatures (in -Wall)]
     Pattern synonym with no type signature:
-      pattern Purep :: forall a.
+      pattern Purep :: forall {a}.
                        (Eq a, Num a) =>
-                       forall a1. Show a1 => a -> a1 -> ([a], ExProv)
+                       forall {a1}. Show a1 => a -> a1 -> ([a], ExProv)
 
 T11213.hs:27:1: warning: [-Wmissing-pattern-synonym-signatures (in -Wall)]
     Pattern synonym with no type signature:
-      pattern Pep :: () => forall a. Show a => a -> ExProv
+      pattern Pep :: () => forall {a}. Show a => a -> ExProv
 
 T11213.hs:28:1: warning: [-Wmissing-pattern-synonym-signatures (in -Wall)]
     Pattern synonym with no type signature:
-      pattern Pup :: forall a. () => Show a => a -> UnivProv a
+      pattern Pup :: forall {a}. () => Show a => a -> UnivProv a
 
 T11213.hs:29:1: warning: [-Wmissing-pattern-synonym-signatures (in -Wall)]
     Pattern synonym with no type signature:
-      pattern Puep :: forall b.
+      pattern Puep :: forall {b}.
                       () =>
-                      forall a. Show a => a -> b -> (ExProv, b)
+                      forall {a}. Show a => a -> b -> (ExProv, b)
diff --git a/testsuite/tests/patsyn/should_compile/T12484.stderr b/testsuite/tests/patsyn/should_compile/T12484.stderr
index d51b6fe393..6e73612518 100644
--- a/testsuite/tests/patsyn/should_compile/T12484.stderr
+++ b/testsuite/tests/patsyn/should_compile/T12484.stderr
@@ -1,4 +1,4 @@
 
 T12484.hs:6:1: warning: [-Wmissing-pattern-synonym-signatures (in -Wall)]
     Pattern synonym with no type signature:
-      pattern RP :: forall a. a -> (a, Bool)
+      pattern RP :: forall {a}. a -> (a, Bool)
diff --git a/testsuite/tests/patsyn/should_compile/T14394.stdout b/testsuite/tests/patsyn/should_compile/T14394.stdout
index f59f62cb78..83e745c60a 100644
--- a/testsuite/tests/patsyn/should_compile/T14394.stdout
+++ b/testsuite/tests/patsyn/should_compile/T14394.stdout
@@ -1,7 +1,7 @@
 pattern Foo :: () => (b ~ a) => a :~~: b
   	-- Defined at <interactive>:5:1
 pattern Bar
-  :: forall k1 k2 (a :: k1) (b :: k2).
+  :: forall {k1} {k2} {a :: k1} {b :: k2}.
      () =>
      (k2 ~ k1, b ~~ a) =>
      a :~~: b