Sends Mesg to Obj. A send message. The class of Obj must have a method defined for this message.
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.
either argument is unbound.
Mesg is not callable or Obj is not a valid object.
Mesg is not a defined message for Obj.
For reasons of efficiency, an Existence Error
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.