Picat Picat Exception Handling and Debugging 2

Question 1

Which built-in activates Picat's execution tracer for debugging?

Accepted Answer

trace

Answer

`trace` activates the Picat tracer, printing each goal as it is called, exited, or failed.

Question 2

What does `spy(Predicate)` do in Picat?

Accepted Answer

Sets a breakpoint on a specific predicate

Answer

`spy(Predicate)` sets a spy point so the debugger activates only when that predicate is called.

Question 3

Which predicate prints the current execution call stack in Picat?

Accepted Answer

print_backtrace

Answer

`print_backtrace` prints the current execution stack, which is helpful for diagnosing errors.

Question 4

How do you measure the execution time of a goal in Picat?

Accepted Answer

time(Goal)

Answer

`time(Goal)` executes Goal and prints the elapsed wall-clock time and inference count.

Question 5

What does `listing(Predicate)` display in Picat's interactive session?

Accepted Answer

The source clauses of the named predicate

Answer

`listing(Predicate)` prints all source clauses for the specified predicate to standard output.

Picat Practice Test