Environment Control

.BD .C please 3 +Key, -Old, +New The predicate please/3is a solution to avoid large numbers of environment control predicates. Later versions will support other environment control as now provided via the predicates style_check/2, leash/1, unknown/2, the tracer predicates, etc. These predicates are then moved into a library for backwards compatibility. The currently available options are:

optimise on/off (default: off)

Switch optimise mode for the compiler on or off (see also the command line option -O). Currently optimised compilation only implies compilation of arithmetic, making it fast, but invisible to the tracer. Later versions might imply various other optimisations such as incorporating a number of basic predicates in the virtual machine (var/1, fail/0, =/2, etc.) to gain speed at the cost of crippling the debugger. Also source level optimisations such as integrating small predicates into their callers, eliminating constant expressions and other predictable constructs. Source code optimisation is never applied to predicates that are declared dynamic (see dynamic/1).

autoload on/off (default: on)

If on autoloading of library functions is enabled. If off autoloading is disabled. See section .

verbose_autoload on/off (default: off)

If on the normal consult message will be printed if a library is autoloaded. By default this message is suppressed. Intended to be used for debugging purposes (e.g. where does this predicate come from?).