Print a term for debugging purposes. The predicate print/1
acts as if defined as below.
print(Term) :-
current_prolog_flag(print_write_options, Options), !,
write_term(Term, Options).
print(Term) :-
write_term(Term, [ portray(true),
numbervars(true),
quoted(true)
]).
The print/1
predicate is used primarily through the ~p escape sequence
of format/2,
which is commonly used in the recipes used by
print_message/2
to emit messages.
The classical definition of this predicate is equivalent to the ISO
predicate write_term/2
using the options portray(true) and
numbervars(true). The portray(true) option
allows the user to implement application-specific printing of terms
printed during debugging to facilitate easy understanding of the output.
See also
portray/1
and library(portray_text). SWI-Prolog adds quoted(true)
to (1) facilitate the copying/pasting of terms that are not affected by
portray/1
and to (2) allow numbers, atoms and strings to be more easily
distinguished, e.g., 42, '42' and "42".
