From: Simon Marlow <simonmar@microsoft.com>
Date: Thu, 6 Apr 2006 11:24:44 +0000 (+0000)
Subject: in the show instance for Exception, print the type of dynamic exceptions
X-Git-Tag: 2007-09-13~397
X-Git-Url: http://git.megacz.com/?a=commitdiff_plain;h=aa95003f89ac4330e8348434155dedcb6c7efcf7;p=ghc-base.git

in the show instance for Exception, print the type of dynamic exceptions
Unfortunately this requires some recursve module hackery to get at
the show instance for Typeable.
---

diff --git a/Data/Dynamic.hs-boot b/Data/Dynamic.hs-boot
index 822ef67..63c81b9 100644
--- a/Data/Dynamic.hs-boot
+++ b/Data/Dynamic.hs-boot
@@ -1,3 +1,5 @@
 {-# OPTIONS -fno-implicit-prelude #-}
 module Data.Dynamic where
+import {-# SOURCE #-} Data.Typeable (TypeRep)
 data Dynamic
+dynTypeRep :: Dynamic -> TypeRep
diff --git a/Data/Typeable.hs-boot b/Data/Typeable.hs-boot
new file mode 100644
index 0000000..4250e56
--- /dev/null
+++ b/Data/Typeable.hs-boot
@@ -0,0 +1,3 @@
+{-# OPTIONS -fno-implicit-prelude #-}
+module Data.Typeable where
+data TypeRep
diff --git a/GHC/Dynamic.hs b/GHC/Dynamic.hs
new file mode 100644
index 0000000..e86b027
--- /dev/null
+++ b/GHC/Dynamic.hs
@@ -0,0 +1,11 @@
+{-# OPTIONS -fno-implicit-prelude #-}
+module GHC.Dynamic (
+ 	Dynamic, TypeRep, dynTypeRep, showsTypeRep
+  ) where
+
+import Data.Dynamic	( Dynamic, dynTypeRep )
+import Data.Typeable	( TypeRep )
+import GHC.Show ( ShowS, shows )
+
+showsTypeRep :: TypeRep -> ShowS
+showsTypeRep = shows
diff --git a/GHC/Dynamic.hs-boot b/GHC/Dynamic.hs-boot
new file mode 100644
index 0000000..a926421
--- /dev/null
+++ b/GHC/Dynamic.hs-boot
@@ -0,0 +1,10 @@
+{-# OPTIONS -fno-implicit-prelude #-}
+module GHC.Dynamic (
+ 	Dynamic, TypeRep, dynTypeRep, showsTypeRep
+  ) where
+
+import {-# SOURCE #-} Data.Dynamic	( Dynamic, dynTypeRep )
+import {-# SOURCE #-} Data.Typeable	( TypeRep )
+import GHC.Show		( ShowS )
+
+showsTypeRep :: TypeRep -> ShowS
diff --git a/GHC/IOBase.lhs b/GHC/IOBase.lhs
index 78a334d..27f7dab 100644
--- a/GHC/IOBase.lhs
+++ b/GHC/IOBase.lhs
@@ -55,7 +55,7 @@ import GHC.List
 import GHC.Read
 
 #ifndef __HADDOCK__
-import {-# SOURCE #-} Data.Dynamic
+import {-# SOURCE #-} GHC.Dynamic
 #endif
 
 -- ---------------------------------------------------------------------------
@@ -743,7 +743,7 @@ instance Show Exception where
   showsPrec _ (RecConError err)	         = showString err
   showsPrec _ (RecUpdError err)	         = showString err
   showsPrec _ (AssertionFailed err)      = showString err
-  showsPrec _ (DynException _err)        = showString "unknown exception"
+  showsPrec _ (DynException err)         = showString "exception :: " . showsTypeRep (dynTypeRep err)
   showsPrec _ (AsyncException e)	 = shows e
   showsPrec _ (BlockedOnDeadMVar)	 = showString "thread blocked indefinitely"
   showsPrec _ (BlockedIndefinitely)	 = showString "thread blocked indefinitely"