Availability:built-in
[YAP]create_prolog_flag(+Key,
+Value, +Options)Create a new Prolog flag. The ISO standard does not foresee creation of
new flags, but many libraries introduce new flags. Options is
a list of the options below. See also user_flags.
- access(+Access)
- Define access rights for the flag. Values are
read_write
and read_only. The default is read_write.
- type(+Atom)
- Define a type restriction. Possible values are
boolean, atom, integer, float
and term. The default is determined from the initial value.
Note that term restricts the term to be ground.
- keep(+Boolean)
- If
true, do not modify the flag if it already exists.
Otherwise (default), this predicate behaves as set_prolog_flag/2
if the flag already exists.
