PL_warning()
prints a standard Prolog warning message to the standard error (user_error)
stream. Please note that new code should consider using PL_raise_exception()
to raise a Prolog exception. See also section
4.10.
- bool PL_warning(format,
a1, ...)
- Print an error message starting with‘
[WARNING: ’,
followed by the output from format, followed by a‘]’and
a newline. Then start the tracer. format and the arguments
are the same as for printf(2). Always returns FALSE.
- int PL_fatal_error(format,
a1, ...)
- As PL_warning(),
but using
[FATAL ERROR: at <time> ...] and
terminates the process after cleanup using abort(). If the
process is a Windows GUI application it uses a message box. This
function should be used if an unrepairable error is detected. For
example, Prolog uses it to signal it cannot find the compiled Prolog
startup or memory allocation fails in a place from where we cannot
gracefully generate an exception.235Currently
most memory allocation except for most of the big allocations such as
for the Prolog stacks.
- int PL_system_error(format,
a1, ...)
- As PL_fatal_error(),
but using
[ERROR: system error:] and provides additional
technical details such as the thread that trapped the error and
backtrace of the C and Prolog stacks. This function should be used to
when an unexpected and unrepairable error is detected. For example,
Prolog uses this after it finds an inconsistency in the data during
garbage collection.
- int PL_api_error(format,
a1, ...)
- As PL_system_error(),
but using
[ERROR: API error:] and provides additional
technical details such as the thread that trapped the error and
backtrace of the C and Prolog stacks. This function is used by the C API
and may be used by other language bindings to report invalid use of the
API. This function causes the process to be terminated.
- bool PL_print_message(atom_t
severity, ...)
- Calls print_message/2
using a term constructed from the remaining arguments that are passed to PL_unify_term().
This is similar to setting up a call to print_message/2
using PL_call_predicate(),
except that it saves and restores possibly pending exceptions and
delayed goals. The severity argument must be valid for
print_message/2.
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