log_enabled is the cached result of whether there exists an enabled logging function. Its main use is to guard logging operations to avoid performing unnecessary computations.

Type of a logging function. It needs to be boxed for higher-rank polymorphism reasons

make key name desc registers a new logger and returns its pp.

set_debug value key enables or disables the loggers corresponding to every character of str according to value.

set_default_debug str declares the debug flags of str to be enabled by default.

get_activated_loggers () fetches the list of activated loggers, listed in a string

reset_loggers () resets the debug flags to those by default.

log_summary () gives the keys and descriptions for logging options.