Picat Exception Handling and Debugging Flashcards
6 cards from real Picat practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Picat Exception Handling and Debugging flashcards as text
Which construct catches exceptions in Picat?
Answer: catch(Goal, Error, Handler)
`catch(Goal, Error, Handler)` executes Goal and runs Handler if a matching exception is raised.
How do you raise an exception in Picat?
Answer: throw(Error)
`throw(Error)` raises an exception carrying the given error term in Picat.
What is the standard ISO format for a type error term in Picat?
Answer: error(type_error(Type, Value), _)
ISO standard errors in Picat use `error(type_error(Type, Culprit), Context)` as the thrown term.
Which error type is thrown when a predicate requires an instantiated argument but receives a variable?
Answer: instantiation_error
`instantiation_error` is thrown when a predicate receives an insufficiently instantiated (unbound) argument.
What happens if no `catch` clause matches a thrown exception in Picat?
Answer: The exception propagates up the call stack
An unmatched exception continues propagating up the call stack until a matching catch or the top level is reached.
How can you write a catch clause that matches any exception regardless of type in Picat?
Answer: catch(Goal, _, Handler)
Using `_` as the error pattern in `catch/3` acts as a wildcard matching any exception term.