create_protocol/3

Description

create_protocol(Identifier, Relations, Directives)

Creates a new, dynamic, protocol. This predicate is often used as a primitive to implement high-level protocol creation methods.

Note that, when opting for runtime generated protocol identifiers, it’s possible to run out of identifiers when using a backend Prolog compiler with bounded integer support. The portable solution, when creating a large number of dynamic protocols in long-running applications, is to recycle, whenever possible, the identifiers.

When using Logtalk multi-threading features, predicates calling this built-in predicate may need to be declared synchronized in order to avoid race conditions.

Modes and number of proofs

create_protocol(?protocol_identifier, @list(protocol_relation), @list(protocol_directive)) - one

Errors

Either Relations or Directives is a variable:
instantiation_error
Identifier is neither a variable nor a valid protocol identifier:
type_error(protocol_identifier, Identifier)
Identifier is already in use:
permission_error(modify, category, Identifier)
permission_error(modify, object, Identifier)
permission_error(modify, protocol, Identifier)
Relations is neither a variable nor a proper list:
type_error(list, Relations)
Repeated entity relation clause:
permission_error(repeat, entity_relation, extends/1)
Directives is neither a variable nor a proper list:
type_error(list, Directives)

Examples

| ?- create_protocol(
        logging,
        [extends(monitoring)],
        [public([log_file/1, log_on/0, log_off/0])]
     ).