mes/lib/srfi/srfi-9.scm
Jan Nieuwenhuizen 28ae662e0e srfi-9 records!
2016-07-24 00:14:40 +02:00

45 lines
1.5 KiB
Scheme

;; Copyright (c) 1993 by Richard Kelsey and Jonathan Rees. See file COPYING.
;; There's no implicit name concatenation, so it can be defined
;; entirely using syntax-rules. Example:
;; (define-record-type foo
;; (make-foo x y)
;; foo? - predicate name is optional
;; (x foo-x)
;; (y foo-y)
;; (z foo-z set-foo-z!))
;; Copyright (c) 1993-2004 by Richard Kelsey and Jonathan Rees. See file COPYING.
(define-syntax define-record-type
(syntax-rules ()
((define-record-type type
(constructor arg ...)
(field . field-stuff)
...)
(begin (define type (make-record-type 'type '(field ...)))
(define constructor (record-constructor type '(arg ...)))
(define-accessors type (field . field-stuff) ...)))
((define-record-type type
(constructor arg ...)
pred
more ...)
(begin (define-record-type type
(constructor arg ...)
more ...)
(define pred (record-predicate type))))))
;; Straightforward version
(define-syntax define-accessors
(syntax-rules ()
((define-accessors type field-spec ...)
(begin (define-accessor type . field-spec) ...))))
(define-syntax define-accessor
(syntax-rules ()
((define-accessor type field accessor)
(define accessor (record-accessor type 'field)))
((define-accessor type field accessor modifier)
(begin (define accessor (record-accessor type 'field))
(define modifier (record-modifier type 'field))))))