Classes with defined Methods: classd.ss

The class/d macro provides a syntax for class expressions that uses define-style syntax to bind instance variables, instead of the letrec-style syntax of class:

  (class/d superclass-expr initialization-variables
     (variable-spec-clause   )
     definition-or-expression
       )

  variable-spec-clause is one of:
     (public variable ...) 
     (override variable ...) 
     (inherit variable ...) 
     (rename (variable variable) ...) 

The superclass-expr and initialization-variables have the same form as in a class expression.

Each definition-or-expression is either an expression or a definition using define, #%define, define-values, #%define-values, define-struct, or #%define-struct. The set of recognized definition forms is fixed; macro expressions that expand to define, for example, are not recognized as definition. No variable can be defined more than once.

A public or override variable-spec-clause indicates that the definitions (in the definition-or-expressions) for the corresponding variables in bind instance variables. Defined variables that are not mentioned in any public or override clause create private instance variables. An inherit or rename clause binds variables to inherited and renamed instance variables (and cannot be redefined in any definition-or-expression).

The definition-or-expressions are evaluated in the order in which they are specified. A definition for an instance variable sets the variable's value immediately, so that calls to methods in the object see the installed value. Prior to its definition, the value of a declared public or override instance variable is the undefined value, as for class.

The class/d* and class/d*/names forms implement define-based analogues of class* and class*/names:

  (class/d* superclass-expr (interface-expr   ) initialization-variables
     (variable-spec-clause   )
     definition-or-expression
       ) 
  (class/d*/names local-names superclass-expr (interface-expr   ) initialization-variables
     (variable-spec-clause   )
     definition-or-expression
       )