2 {-# OPTIONS_GHC -XNoImplicitPrelude #-}
3 {-# OPTIONS_HADDOCK hide #-}
4 -----------------------------------------------------------------------------
7 -- Copyright : (c) The University of Glasgow, 1994-2002
8 -- License : see libraries/base/LICENSE
10 -- Maintainer : cvs-ghc@haskell.org
11 -- Stability : internal
12 -- Portability : non-portable (GHC extensions)
14 -- The "GHC.Err" module defines the code for the wired-in error functions,
15 -- which have a special type in the compiler (with \"open tyvars\").
17 -- We cannot define these functions in a module where they might be used
18 -- (e.g., "GHC.Base"), because the magical wired-in type will get confused
19 -- with what the typechecker figures out.
21 -----------------------------------------------------------------------------
27 , divZeroError -- :: a
28 , overflowError -- :: a
30 , error -- :: String -> a
43 %*********************************************************
45 \subsection{Error-ish functions}
47 %*********************************************************
50 -- | 'error' stops execution and displays an error message.
52 error s = throw (ErrorCall s)
54 -- | A special case of 'error'.
55 -- It is expected that compilers will recognize this and insert error
56 -- messages which are more appropriate to the context in which 'undefined'
60 undefined = error "Prelude.undefined"
63 %*********************************************************
65 \subsection{Compiler generated errors + local utils}
67 %*********************************************************
69 Used for compiler-generated error message;
70 encoding saves bytes of string junk.
75 absentErr = error "Oops! The program has entered an `absent' argument!\n"
78 Divide by zero and arithmetic overflow.
79 We put them here because they are needed relatively early
80 in the libraries before the Exception type has been defined yet.
83 {-# NOINLINE divZeroError #-}
85 divZeroError = throw DivideByZero
87 {-# NOINLINE overflowError #-}
89 overflowError = throw Overflow