bb_contains_key/2

checks whether a key is member of the blackboard.

bb_contains_key(+Board, ?Key)

Blackboards are collections of (Key,Value) tuples. bb_contains_key/2 allows to retrieve the Key part of the blackboard.

If Key is not a free variable then bb_contains_key/2 succeeds if the blackboard Board contains the key Key.
If Key is a free variable then by backtracking bb_contains_key/2 lists all keys which are elements of the blackboard Board.

Arguments 

Board                  blackboard
Key                    ground term

Examples

Assume there exists a blackboard 'blackboard' with elements (100, abc), (101, element101), (102, abc).

bb_contains_key(blackboard, 100). Succeeds.
bb_contains_key(blackboard, X). Succeeds three times with substitution
X <- 100
X <- 101
X <- 102

Standard

This predicate is not part of the ISO-Prolog Standard.

See also

bb_clear/1, bb_clear_2/2, bb_create/1, bb_contains/2, bb_contains_key/2, bb_get/3, bb_get_4/4, bb_put/3, bb_put_4/4, bb_remove/2. bb_keys/2. bb_elements/2.

Darueber read on...