-% -----------------------------------------------------------------------------
-% $Id: Err.lhs,v 1.4 2002/04/11 12:03:43 simonpj Exp $
-%
-% (c) The University of Glasgow, 1994-2000
-%
-
-\section[GHC.Err]{Module @GHC.Err@}
-
-The GHC.Err module defines the code for the wired-in error functions,
-which have a special type in the compiler (with "open tyvars").
-
-We cannot define these functions in a module where they might be used
-(e.g., GHC.Base), because the magical wired-in type will get confused
-with what the typechecker figures out.
-
\begin{code}
-{-# OPTIONS -fno-implicit-prelude #-}
+{-# OPTIONS_GHC -fno-implicit-prelude #-}
+-----------------------------------------------------------------------------
+-- |
+-- Module : GHC.Err
+-- Copyright : (c) The University of Glasgow, 1994-2002
+-- License : see libraries/base/LICENSE
+--
+-- Maintainer : cvs-ghc@haskell.org
+-- Stability : internal
+-- Portability : non-portable (GHC extensions)
+--
+-- The "GHC.Err" module defines the code for the wired-in error functions,
+-- which have a special type in the compiler (with \"open tyvars\").
+--
+-- We cannot define these functions in a module where they might be used
+-- (e.g., "GHC.Base"), because the magical wired-in type will get confused
+-- with what the typechecker figures out.
+--
+-----------------------------------------------------------------------------
+
module GHC.Err
(
irrefutPatError
, recConError
, runtimeError -- :: Addr# -> a -- Addr# points to UTF8 encoded C string
- , absentErr, parError -- :: a
- , seqError -- :: a
+ , absentErr -- :: a
+ , divZeroError -- :: a
, error -- :: String -> a
, assertError -- :: String -> Bool -> a -> a
, undefined -- :: a
) where
+#ifndef __HADDOCK__
import GHC.Base
import GHC.List ( span )
import GHC.Exception
+#endif
\end{code}
%*********************************************************
%*********************************************************
\begin{code}
--- error stops execution and displays an error message
+-- | 'error' stops execution and displays an error message.
error :: String -> a
error s = throw (ErrorCall s)
+-- | A special case of 'error'.
-- It is expected that compilers will recognize this and insert error
--- messages which are more appropriate to the context in which undefined
+-- messages which are more appropriate to the context in which 'undefined'
-- appears.
undefined :: a
encoding saves bytes of string junk.
\begin{code}
-absentErr, parError, seqError :: a
+absentErr :: a
absentErr = error "Oops! The program has entered an `absent' argument!\n"
-parError = error "Oops! Entered GHCerr.parError (a GHC bug -- please report it!)\n"
-seqError = error "Oops! Entered seqError (a GHC bug -- please report it!)\n"
\end{code}
\begin{code}
}
not_bar c = c /= '|'
\end{code}
+
+Divide by zero. We put it here because it is needed relatively early
+in the libraries before the Exception type has been defined yet.
+
+\begin{code}
+{-# NOINLINE divZeroError #-}
+divZeroError :: a
+divZeroError = throw (ArithException DivideByZero)
+\end{code}
+