1.15.1 The class PlException

This subclass of PlExceptionBase is used to represent exceptions. Currently defined methods are:

PlException :: PlException(const PlTerm &)

Create an exception from a general Prolog term. This provides the interface for throwing any Prolog terms as an exception.

std::string as_string()

The exception is translated into a message as produced by print_message/2. The character data is stored in a ring. Example:

  ...;
  try
  { PlCall("consult(load)");
  } catch ( PlException& ex )
  { cerr << ex.as_string() << endl;
  }

int plThrow()

Used in the PREDICATE() wrapper to pass the exception to Prolog. See PL_raise_exeption().

1.15.1.1 The function PlTypeError

A type error expresses that a term does not satisfy the expected basic Prolog type.

PlTypeError :: PlTypeError(const std::string& expected, const PlTerm &actual)

Creates an ISO standard Prolog error term expressing the expected type and actual term that does not satisfy this type.

1.15.1.2 The function PlDomainError

A domain error expresses that a term satisfies the basic Prolog type expected, but is unacceptable to the restricted domain expected by some operation. For example, the standard Prolog open/3 call expect an io_mode (read, write, append, ...). If an integer is provided, this is a type error, if an atom other than one of the defined io-modes is provided it is a domain error.

PlDomainError :: PlDomainError(const std::string& expected, const PlTerm &actual)

Creates an ISO standard Prolog error term expressing a the expected domain and the actual term found.