You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
24 lines
603 B
Racket
24 lines
603 B
Racket
#lang racket/base
|
|
(require "racket.rkt")
|
|
(provide (all-defined-out))
|
|
|
|
#|
|
|
approximates
|
|
https://github.com/mbutterick/restructure/blob/master/src/Enum.coffee
|
|
|#
|
|
|
|
(define-subclass xenomorph-base% (Enum type [options empty])
|
|
|
|
(define/augment (decode stream . _)
|
|
(define index (send type decode stream))
|
|
(or (list-ref options index) index))
|
|
|
|
(define/augment (size . _) (send type size))
|
|
|
|
(define/augment (encode stream val [ctx #f])
|
|
(define index (index-of options val))
|
|
(unless index
|
|
(raise-argument-error 'Enum:encode "valid option" val))
|
|
(send type encode stream index)))
|
|
|