content: {-
  From: Jon Hill <hilly@dcs.qmw.ac.uk@jess.gla.ac.uk@pp.dcs.glasgow.ac.uk>
  To: glasgow-haskell-bugs
  Subject: Unfriendly error message
  Date: Thu, 25 Jun 1992 09:22:55 +0100
  
  Hello again,
  
  I came across a rather nasty error message when I gave a function an
  incorrect type signature (the context is wrong). I can remember reading 
  in the source about this problem - I just thought I'd let you know anyway :-)
  -}
  module ShouldFail where
  
  
  test::(Num a, Eq a) => a -> Bool
  test x = (x `mod` 3) == 0
  
  {-
  granite> ndph bug002.ldh
  Data Parallel Haskell Compiler, version 0.01 (Glasgow 0.07)
  
   
  "<unknown>", line <unknown>: Cannot express dicts in terms of dictionaries available:
  dicts_encl:
     "<built-in>", line : dict.87 :: <Num a>
     "<built-in>", line : dict.88 :: <Eq a>
  dicts_encl':
     "<built-in>", line : dict.87 :: <Num a>
     "<built-in>", line : dict.88 :: <Eq a>
  dicts:
     "<built-in>", line : dict.87 :: <Num a>
     "<built-in>", line : dict.88 :: <Eq a>
  super_class_dict: "<built-in>", line : dict.80 :: <Integral a>
  Fail: Compilation errors found
  
  dph: execution of the Haskell compiler had trouble
  
  -}
  