2.9.7 Miscellaneous (version 2)

bool is_null()

t.is_null() is the same as t.C_ == PlTerm::null

bool not_null()

t.not_null() is the same as t.C_ != PlTerm::null

bool reset()

t.reset() is the same as t.C_ = PlTerm::null

bool reset(term_t)

t.reset(x) is the same as t.C_ = x

int PlTerm::type()

Yields the actual type of the term as PL_term_type(). Return values are PL_VARIABLE, PL_FLOAT, PL_INTEGER, PL_ATOM, PL_STRING or PL_TERM

To avoid very confusing combinations of constructors and therefore possible undesirable effects a number of subclasses of PlTerm have been defined that provide constructors for creating special Prolog terms. These subclasses are defined below.