(goops.info.gz) Generic Function Internals

Info Catalog

(goops.info.gz) Basic Generic Function Creation

(goops.info.gz) Creating Generic Functions

(goops.info.gz) Extending Guiles Primitives

 
 Generic Function Internals
 --------------------------
 
 `define-generic' calls `ensure-generic' to upgrade a pre-existing
 procedure value, or `make' with metaclass `<generic>' to create a new
 generic function.
 
 `define-accessor' calls `ensure-accessor' to upgrade a pre-existing
 procedure value, or `make-accessor' to create a new accessor.
 
  - procedure: ensure-generic old-definition [name]
      Return a generic function with name NAME, if possible by using or
      upgrading OLD-DEFINITION.  If unspecified, NAME defaults to `#f'.
 
      If OLD-DEFINITION is already a generic function, it is returned
      unchanged.
 
      If OLD-DEFINITION is a Scheme procedure or procedure-with-setter,
      `ensure-generic' returns a new generic function that uses
      OLD-DEFINITION for its default procedure and setter.
 
      Otherwise `ensure-generic' returns a new generic function with no
      defaults and no methods.
 
  - procedure: make-generic [name]
      Return a new generic function with name `(car NAME)'.  If
      unspecified, NAME defaults to `#f'.
 
 `ensure-generic' calls `make' with metaclasses `<generic>' and
 `<generic-with-setter>', depending on the previous value of the
 variable that it is trying to upgrade.
 
 `make-generic' is a simple wrapper for `make' with metaclass
 `<generic>'.
 
  - procedure: ensure-accessor proc [name]
      Return an accessor with name NAME, if possible by using or
      upgrading PROC.  If unspecified, NAME defaults to `#f'.
 
      If PROC is already an accessor, it is returned unchanged.
 
      If PROC is a Scheme procedure, procedure-with-setter or generic
      function, `ensure-accessor' returns an accessor that reuses the
      reusable elements of PROC.
 
      Otherwise `ensure-accessor' returns a new accessor with no defaults
      and no methods.
 
  - procedure: make-accessor [name]
      Return a new accessor with name `(car NAME)'.  If unspecified,
      NAME defaults to `#f'.
 
 `ensure-accessor' calls `make' with metaclass `<generic-with-setter>',
 as well as calls to `ensure-generic', `make-accessor' and (tail
 recursively) `ensure-accessor'.
 
 `make-accessor' calls `make' twice, first with metaclass `<generic>' to
 create a generic function for the setter, then with metaclass
 `<generic-with-setter>' to create the accessor, passing the setter
 generic function as the value of the `#:setter' keyword.
 

Info Catalog

(goops.info.gz) Basic Generic Function Creation

(goops.info.gz) Creating Generic Functions

(goops.info.gz) Extending Guiles Primitives