base-4.18.1.0: Basic libraries

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)
Safe Haskell | Trustworthy
Language | Haskell2010

GHC.Err

Description

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.

Synopsis

- absentErr :: a
- error :: forall (r :: RuntimeRep). forall (a :: TYPE r). HasCallStack => [Char] -> a
- errorWithoutStackTrace :: forall (r :: RuntimeRep). forall (a :: TYPE r). [Char] -> a
- undefined :: forall (r :: RuntimeRep). forall (a :: TYPE r). HasCallStack => a

# Documentation

absentErr :: a Source #

Used for compiler-generated error message; encoding saves bytes of string junk.

error :: forall (r :: RuntimeRep). forall (a :: TYPE r). HasCallStack => [Char] -> a Source #

`error` stops execution and displays an error message.

errorWithoutStackTrace :: forall (r :: RuntimeRep). forall (a :: TYPE r). [Char] -> a Source #

A variant of `error` that does not produce a stack trace.

Since: base-4.9.0.0

undefined :: forall (r :: RuntimeRep). forall (a :: TYPE r). HasCallStack => a Source #

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` appears.