10.13.6.2 <</2

Synopsis

+Obj << +Att

Arguments

Obj

object

Att

term

Description

Send a message to Obj to store the value of Att in the object. A put message. Att must be an attribute that can be stored in objects of Obj's class.

A clause with <</2 as the principal functor of its head is a method definition clause. Such clauses only occur within the scope of a class definition. They are expanded at compile time.

Put methods are automatically generated for public slots.

Exceptions

instantiation_error

either argument is unbound.

domain_error

Mesg is not callable or Obj is not a valid object.

existence_error

Mesg is not a defined message for Obj.

Caveat

For reasons of efficiency, an existence_error exception will only be raised if the code that sends the message is compiled with debugging enabled (see debug_message), or if the message is not determined at compile-time. In other circumstances, the message will simply fail.

Calls to the <</2 predicate will be compiled into more efficient code if the obj_decl module is loaded at compile time.

See Also

<-/2, >>/2, direct_message/4, message/4, store_slot/2