Err package:base
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.
This is thrown when the user calls
error. The
String
is the argument given to
error.
Historically, there was a second
String for the location, but
it was subsumed by the backtrace mechanisms (since base-4.22).
Deprecated: ErrorCallWithLocation has been deprecated in favour of
ErrorCall (which does not have a location). Backtraces are now handled
by the backtrace exception mechanisms exclusively.
C-specific Marshalling support: Handling of C "errno" error codes.
Haskell representation for
errno values. The implementation
is deliberately exposed, to allow users to add their own definitions
of
Errno values.
Routines for testing return values and raising a userError
exception in case of values indicating an error state.
Throw an error when an illegal sequence is encountered
A description of a custom type error.
error stops execution and displays an error message.
A variant of
error that does not produce a stack trace.
Construct an
IOError based on the given
Errno value. The
optional information can be used to improve the accuracy of error
messages.
Calls
perror to indicate that there is a type error or similar
in the given argument.
Calls
perror to indicate an unknown format letter for a given
type.
Calls
perror to indicate that there is a missing argument in
the argument list.
Calls
perror to indicate that the format string ended early.
Deprecated: error appends the call stack now
The Haskell 2010 type for exceptions in the
IO monad. Any I/O
operation may raise an
IOError instead of returning a result.
For a more general type of exception, including also those that arise
in pure code, see
Exception.
In Haskell 2010, this is an opaque type.