chibi-scheme/lib/srfi/99/records/syntactic.scm
Alex Shinn 8b5eb68238 File descriptors maintain a reference count of ports open on them
They can be close()d explicitly with close-file-descriptor, and
will close() on gc, but only explicitly closing the last port on
them will close the fileno.  Notably needed for network sockets
where we open separate input and output ports on the same socket.
2014-02-20 22:32:50 +09:00

116 lines
5.6 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)))
'())
;; accessors
,@(map (lambda (f)
(let ((g (if (and (pair? f) (pair? (cdr f)))
(cadr f)
(string->symbol
(string-append name-str
"-"
(id->string (if (pair? f) (car f) 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 (and (pair? f)
(if (and (pair? (cdr f)) (pair? (cddr f)))
(car (cddr f))
(string->symbol
(string-append name-str
"-"
(id->string (car 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-name
(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)))))))))))
'()))))))