Errors

Description

In Funky errors are handled via so-called error objects.

In the case an error occurs:

if a function would return a single value, it returns an error object instead

if a function would return several values, it returns the expected number of results, replacing each result with the error object

if a function would return no value at all, it will return a single error object to its caller, which results in an error in the caller and leads to propagation of the error

Error objects can contain only very few and special methods. Any attempt to access other methods will propagate the error.

To check whether a value is an error object or not, use std::is_an_error.

Example

load $buf filename on buf.is_an_error: Error " Could not load file "@(filename)"!

std::Error	displays an error message and terminates the program
std::check	checks its argument
std::errno_of	retrieves the errno value of the error object
std::error_category_of	retrieves the error category of the error object
std::error_check	raises an error if any of its arguments is an error object
std::error_details_of	retrieves the error details of the error object
std::error_message_text_of	retrieves the error message text of the error object
std::is_an_error	returns true if the argument denotes an error-object
std::try	recover an error object
std_types::error	the prototype object for all error objects
std_types::error.std::is_an_error	error objects are errors
std_types::error/std::error_category_of	returns the error category of the error object
std_types::error/std::error_details_of	returns the error details of the error object
std_types::error/std::error_message_text_of	returns the error message text of the error object
std_types::object.std::is_an_error	objects are not errors by default
std_types::undefined.std::is_an_error	the special undefined object is not an error