mpg-ref-debugging - SICStus Prolog

debugging

Prints out current debugging state

debugging/0 displays information on the terminal about the current debugging state. It shows

The top-level state of the debugger, which is one of
debug
The debugger is on but will not show anything or stop for user interaction until a spypoint is reached.

trace
The debugger is on and will show everything. As soon as you type a goal, you will start seeing a debugging trace. After printing each trace message, the debugger may or may not stop for user interaction: this depends on the type of leashing in force (see below).

zip
The debugger is on but will not show anything or stop for user interaction until a spypoint is reached. The debugger does not even keep any information of the execution of the goal till the spypoint is reached and hence you will not be able to see the ancestors of the goal when you reach the spypoint.

off
The debugger is off.

The top-level state can be controlled by the predicates debug/0, nodebug/0, trace/0, notrace/0 zip/0, nozip/0, and prolog_flag/3.
The type of leashing in force. When the debugger prints a message saying that it is passing through a particular port (one of Call, Exit, Redo, Fail, or Exception) of a particular procedure, it stops for user interaction only if that port is leashed. The predicate leash/1 can be used to select which of the seven ports you want to be leashed.
All the current spypoints. Spypoints are controlled by the predicates spy/[1,2], nospy/1, nospyall/0, add_breakpoint/2, disable_breakpoints/1, enable_breakpoints/1, and remove_breakpoints/1.