chibi-scheme/lib/srfi/99/records/syntactic.scm

110 lines
5.2 KiB
Scheme

(define-syntax define-record-type
(er-macro-transformer
(lambda (expr rename compare)
(let* ((id->string (lambda (x) (symbol->string (identifier->symbol x))))
(name+parent (cadr expr))
(name (if (pair? name+parent) (car name+parent) name+parent))
(parent (and (pair? name+parent) (cadr name+parent)))
(name-str (id->string name))
(procs (cddr expr))
(make (car procs))
(make-name (if (eq? make #t)
(string->symbol (string-append "make-" name-str))
(if (pair? make) (car make) make)))
(pred (cadr procs))
(pred-name (if (eq? pred #t)
(string->symbol (string-append name-str "?"))
pred))
(fields (cddr procs))
(field-names (map (lambda (x) (if (pair? x) (car x) x)) fields))
(make-fields (if (pair? make) (cdr make) (and (not parent) field-names)))
(_make (rename '%make))
(_define (rename 'define))
(_lambda (rename 'lambda))
(_let (rename 'let))
(_register (rename 'register-simple-type))
(_slot-set! (rename 'slot-set!))
(_vector->list (rename 'vector->list))
(_type_slot_offset (rename 'type-slot-offset))
(_rtd-all-field-names (rename 'rtd-all-field-names)))
`(,(rename 'begin)
;; type
(,_define ,name (,_register ,name-str ,parent ',field-names))
;; predicate
,@(if pred-name
`((,_define ,pred-name
(,(rename 'make-type-predicate)
,(id->string pred-name)
,name)))
#f)
;; accessors
,@(map (lambda (f)
(let ((g (if (and (pair? f) (pair? (cdr f)))
(cadr f)
(and (identifier? f)
(string->symbol
(string-append name-str "-" (id->string f)))))))
(and g
`(,_define ,g
(,(rename 'make-getter)
,(id->string g)
,name
(,_type_slot_offset ,name ',(if (pair? f) (car f) f)))))))
fields)
,@(map (lambda (f)
(let ((s (if (and (pair? f) (pair? (cdr f)) (pair? (cddr f)))
(car (cddr f))
(and (identifier? f)
(string->symbol
(string-append name-str "-" (id->string f) "-set!"))))))
(and s
`(,_define ,s
(,(rename 'make-setter)
,(id->string s)
,name
(,_type_slot_offset ,name ',(if (pair? f) (car f) f)))))))
fields)
;; constructor
,(if make-fields
(let ((fields (map (lambda (f) (cons (rename f) f)) make-fields)))
`(,_define ,make-name
,(let lp ((ls fields) (sets '()))
(cond
((null? ls)
`(,_let ((,_make (,(rename 'make-constructor)
,(id->string make-name)
,name)))
(,_lambda ,(map car fields)
(,_let ((res (,_make)))
,@sets
res))))
(else
(let ((field (assq (cdar ls) fields)))
(cond
((and (pair? field) (pair? (cdr field)) (pair? (cddr field)))
(lp (cdr ls)
(cons (list (car (cddr field)) 'res (cdar ls)) sets)))
(else
(lp (cdr ls)
(cons `(,_slot-set! ,name res (,_type_slot_offset ,name ',(cdar ls)) ,(caar ls)) sets))))))))))
`(,_define ,make-name
(,_let ((,_make (,(rename 'make-constructor)
,(id->string make-name)
,name)))
(,_lambda args
(,_let ((res (,_make)))
(let lp ((a args)
(p (,_vector->list (,_rtd-all-field-names ,name))))
(cond
((null? a)
(if (null? p)
res
(error ,(string-append "not enough arguments to " (id->string make-name) ": missing")
p)))
((null? p)
(error ,(string-append "too many arguments to " (id->string make-name))
a))
(else
(,_slot-set! ,name res (,_type_slot_offset ,name (car p)) (car a))
(lp (cdr a) (cdr p)))))))))))))))