Interoperability Macros for roos and racket/class🔗ℹ

package: roos

This module provides a compatibility layer between the roos object system and the standard racket/class system. It exports the macros send, ->, and new, which automatically dispatch to the appropriate implementation based on the type of the given object or class.

1 Macros🔗ℹ

syntax
send

(send obj method arg ...) A generic message-send macro that works for both Roos objects and standard Racket class objects. If obj is a Roos object (roos-object?), it uses the Roos dispatch (->). Otherwise, it falls back to the original send from racket/class.

Examples:

> (def-roos (t x) this (supers)
(y x)
((f a) (* a x)))
> (define o (new t 5))
> (send o f 2)
10

syntax
->

(-> obj method arg ...) Similar to send, but uses a cleaner Racket-style method call syntax. Dispatches to either Roos or Racket based on the object type.

Examples:

> (def-roos (t x) this (supers)
(y x)
((f a) (* a x)))
> (define o (new t 5))
> (-> o f 3)
15

syntax
new

(new class arg ...) Creates a new object. If class is a Roos class (roos-class?), then roos-new is used. Otherwise, the standard new from racket/class is used, supporting initialization arguments such as (init-field val).

(require roos/class) ; instead of racket/class

(define (t% x)
  (class object%
    (init-field (y* x))
    (define/public (y) y*)
    (define/public (y! x) (set! y* x))
    (define/public (f a) (* (send this y) a))
    (super-new)))

(def-roos (t x) this (supers)
  (y x)
  ((f a) (* (-> this y) a)))

(displayln
(let ((cl (t% 5)))
   (let ((o (new cl)))
     (= (send o f 2) 10))))

(displayln
(let ((cl (t% 6)))
   (let ((o (new cl)))
     (= (-> o f 3) 18))))

(displayln
(let ((o (new t 8)))
   (= (-> o f 4) 32)))

(displayln
(= (send (new t 4) f 2) 8))

2 Implementation Notes🔗ℹ

The original Racket send and -> are renamed to old-send and old-> internally.
The Roos-aware macros detect the object or class type and route to the correct implementation.
new* is a helper macro that transforms arguments into (v x) form when needed.

3 Testing🔗ℹ

The module includes an internal test suite using RackUnit. It validates consistent behavior of send, ->, and new across both Racket classes and Roos classes.