scsh-0.6/scheme/alt/jar-defrecord.scm

48 lines
1.5 KiB
Scheme

; Copyright (c) 1993-1999 by Richard Kelsey and Jonathan Rees. See file COPYING.
; This is JAR's define-record-type, which doesn't resemble Richard's.
; There's no implicit name concatenation, so it can be defined
; entirely using syntax-rules. Example:
; (define-record-type foo :foo
; (make-foo x y)
; foo? - predicate name is optional
; (x foo-x)
; (y foo-y)
; (z foo-z set-foo-z!))
(define-syntax define-record-type
(syntax-rules ()
((define-record-type ?id ?type
(?constructor ?arg ...)
(?field . ?field-stuff)
...)
(begin (define ?type (make-record-type '?id '(?field ...)))
(define ?constructor (record-constructor ?type '(?arg ...)))
(define-accessors ?type (?field . ?field-stuff) ...)))
((define-record-type ?id ?type
(?constructor ?arg ...)
?pred
?more ...)
(begin (define-record-type ?id ?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))))
((define-accessor ?type ?field)
(begin))))