deriving Read wibble

[Sigbjorn Finne (Intl Vendor)]

Hi,

loopy behaviour from derived Read code - loading the following

\begin{code}
module Main(main) where

infix 4 :^:
data Tree a 
  =  Leaf a  | Tree a :^: Tree a 
      deriving (Show, Read)

val1 :: Tree Int
val1 = Leaf 2

main = do
  print val1
  print ((read (show val1))::Tree Int)
\end{code}

into Hugs98 (March1999) gives,

Prelude> :l Foo
..
Main> main
Leaf 2

ERROR: Control stack overflow
Main> 

--sigbjorn