Section "objects"

This section mainly deals with accessing and modifying an unordered map data type, a Prolog reference type. The predicate ir_object_new/1 creates a new unordered map. Keys are restricted to atoms. Values are accessed or modified unchanged as Prolog terms, and can be unordered map data types itself, allowing for the nesting of objects.

The unordered map data type is not meant to provide a Prolog feature term, since the data type does neither participate in unification or nor in Prolog garbage collection. Although not forbidden, non-atomic values are therefore not recommended and should be restricted to proper ground terms. On the other hand, the native garbage collection stays intact.

The following object access predicates are provided:
ir_object_new(O):
The predicate succeeds in O with a new host object.
ir_object_current(O, K, V):
The predicate succeeds in V with the value of the key K in the host object O.
ir_object_set(O, K, V):
The predicate sets the value of the key K in the host object O to V.
ir_object_keys(O, L):
The predicate succeeds in L with the keys of the host object O.
ir_float_value(P, H):
If P is instantiated, then the predicate succeeds in H with the host float of P, otherwise in P with the Prolog float of H.

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