►Fundamentals II (Honors)
Introduction to Class-based Program Design
▼Class system
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require
provide
define-class
set-field!
super
implements
constructor
this
fields
define/ public
define/ private
new
field
send
define-interface
Version: 5.3.0.1
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5 Class 3

 #lang class/3

(require module-name ...)
Imports all the modules named module-names.

(provide id ...)
Makes all of the ids available to other modules.

(define-class class-name
  super-spec
  implements-spec
  fields-spec
  constructor-spec
  method-spec ...)
 
super-spec = 
  | (super super-name)
     
implements-spec = 
  | (implements interface-name ...)
     
fields-spec = 
  | (fields field-name ...)
     
constructor-spec = 
  | (constructor (arg ...) body ...)
     
method-spec = 
(define/public (method-name arg ...)
  body)
  | 
(define/private (method-name arg ...)
  body)
Defines a new class named class-name, just as with class/2. However, the body of each method may use set-field! to change the value of a field. For example.

> (define-class c%
    (fields x)
    (define/public (double-x!) (set-field! x (* (field x) 2))))
> (define c (c% 5))
> (send c x)

5

> (send c double-x!)
> (send c x)

10

(set-field! f e)
Changes the value of field f to be the result of e.

(super class-or-interface-name)
(implements interface-name ...)
(constructor (args ...) body)
See define-class and define-interface.

this
(fields id ...)
(define/public (method-name id ...) body)
(define/private (method-name id ...) body)
(new class-name arg ...)
(field field-name)
(send object message arg ...)
These have the same meaning as in class/0.

(define-interface interface-name
  (super super-interface) ...
  (method-name ...))
This has the same meaning as in class/1.

}

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