From 181da0c3e14dc2794f1a68766fc2c46c8948f527 Mon Sep 17 00:00:00 2001
From: simonpj <unknown>
Date: Wed, 30 Jun 1999 09:49:55 +0000
Subject: [PATCH] [project @ 1999-06-30 09:49:55 by simonpj] Add a test for
deriving Show (f (f a)); makes Hugs hang
---
ghc/tests/deriving/should_fail/drvfail001.hs | 25 +++++++++++++++++++
.../deriving/should_fail/drvfail001.stderr | 7 ++++++
2 files changed, 32 insertions(+)
create mode 100644 ghc/tests/deriving/should_fail/drvfail001.hs
create mode 100644 ghc/tests/deriving/should_fail/drvfail001.stderr
diff --git a/ghc/tests/deriving/should_fail/drvfail001.hs b/ghc/tests/deriving/should_fail/drvfail001.hs
new file mode 100644
index 000000000000..aa7867f34f63
--- /dev/null
+++ b/ghc/tests/deriving/should_fail/drvfail001.hs
@@ -0,0 +1,25 @@
+{- From: Ian Bayley
+ Sent: Tuesday, June 29, 1999 3:39 PM
+ To: hugs-bugs@haskell.org
+ Subject: Show for higher-order nested datatypes
+
+
+ Is "deriving Show" meant to work for higher-order nested datatypes ?
+ Hugs hangs when loading in the following file:
+-}
+
+module Foo where
+
+type SqMat a = SM Nil a
+
+data SM f a = ZeroS (f (f a)) | SuccS (SM (Cons f) a)
+ deriving Show
+
+
+data Nil a = MkNil deriving Show
+
+data Cons f a = MkCons a (f a)
+ deriving Show
+
+
+
diff --git a/ghc/tests/deriving/should_fail/drvfail001.stderr b/ghc/tests/deriving/should_fail/drvfail001.stderr
new file mode 100644
index 000000000000..887f7cd25ed0
--- /dev/null
+++ b/ghc/tests/deriving/should_fail/drvfail001.stderr
@@ -0,0 +1,7 @@
+
+drvfail001.hs:11:
+ No instance for `Show (f (f a))'
+ When deriving classes for `SM'
+
+Compilation had errors
+
--
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