MethodDefinition-class        package:methods        R Documentation

Classes to Represent Method Definitions

Description:

     These classes extend the basic class '"function"' when functions
     are to be stored and used as method definitions.

Details:

     Method definition objects are functions with additional
     information defining how the function is being used as a method. 
     The 'target' slot is the class signature for which the method will
     be dispatched, and the 'defined' slot the signature for which the
     method was orignally specified (that is, the one that appeared in
     some call to 'setMethod').

Objects from the Class:

     The action of setting a method by a call to 'setMethod' creates an
     object of this class.  It's unwise to create them directly.

     The class '"SealedMethodDefinition"' is created by a call to
     'setMethod' with argument 'sealed = TRUE'.  It has the same
     representation as '"MethodDefinition"'.

Slots:

     '.Data': Object of class '"function"'; the data part of the
          definition. 

     'target': Object of class '"signature"'; the signature for which
          the method was wanted. 

     'defined': Object of class '"signature"'; the signature for which
          a method was found.  If the method was inherited, this will
          not be identical to 'target'. 

Extends:

     Class '"function"', from data part.
      Class '"PossibleMethod"', directly.
      Class '"OptionalMethods"', by class '"function"'.

See Also:

     class 'MethodsList-class' for the objects defining sets of methods
     associated with a particular generic function.  The individual
     method definitions stored in these objects are from class
     'MethodDefinition', or an extension. 'MethodWithNext-class' for an
     extension used by 'callNextMethod'.

