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.
Documentation
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 #