racket/collects/mzlib/class-old.ss
2005-05-27 18:56:37 +00:00

1000 lines
31 KiB
Scheme

;; Object system, same as MzScheme version 103 and earlier.
;; This was a fairly simple implementation until it was extended to
;; handle primitive classes (e.g., for MrEd). Now it's a mess.
(module class-old mzscheme
(require-for-syntax (lib "stx.ss""syntax")
(lib "name.ss""syntax"))
(define insp (current-inspector))
(define-values (prop:object object? object-ref) (make-struct-type-property 'object))
(define-struct class (name
object-make object-slot-ref object-slot-set!
width method-prim-vec
pos supers
interface
public-ht public-ids
init-old-indices ;; rename
init-define-indices ;; override, public
replace-indices ;; override
init-new-indices ;; inherit, override, public
go go-arity
struct:prim prop:dispatch prim-methods
immediate-primitive?))
;; simplistic implementation for now:
(define-struct interface (name supers public-ids class))
(define undefined (letrec ([x x]) x))
(define object<%> (make-interface 'object% null null #f))
(define object% (make-class 'object%
'make-obj 'slot-ref 'slot-set! 0 (vector)
0 (vector #f)
object<%>
(make-hash-table)
null null null null null
(lambda ()
(let ([object%-init (lambda () (void))])
object%-init))
0
#f #f #f #f))
(set-interface-class! object<%> object%)
(vector-set! (class-supers object%) 0 object%)
(define-values (struct:obj make-obj)
(let-values ([(struct:obj make-obj obj? obj-accessor obj-mutator)
(make-struct-type 'object #f 0 0 #f (list (cons prop:object (box object%))) insp)])
(set-class-object-make! object% make-obj)
(set-class-object-slot-ref! object% obj-accessor)
(set-class-object-slot-set!! object% obj-mutator)
(values struct:obj make-obj)))
(define (obj-class o)
(unbox (object-ref o)))
(define (slot-ref o p)
(unbox/prim-resolve ((class-object-slot-ref (unbox (object-ref o))) o p) o))
(define (make-naming-constructor type name)
(let-values ([(struct: make- ? -accessor -mutator)
(make-struct-type name type 0 0 #f null insp)])
make-))
(define skip (gensym))
(define-struct lazy-prim-method (m))
(define (unbox/prim-resolve b o)
(let ([v (unbox b)])
(if (lazy-prim-method? v)
(begin
(set-box! b (lambda r (apply (lazy-prim-method-m v) o r)))
(unbox b))
v)))
(define (make-prim-class struct:prim prim-side-box prop:dispatch prim-init name super old-mnames new-mnames methods)
(let ([c (compose-class name (or super object%) null
null ;; rename
null ;; inherit
old-mnames ;; override
new-mnames ;; public
(let ([lazys
(map make-lazy-prim-method
methods)])
(lambda (this super-init . pub-defines+pub-mutables)
(lambda args
(if super (super-init skip) (super-init))
(unless (and (pair? args)
(eq? (car args) skip))
(apply prim-init this args))
(unless (null? pub-defines+pub-mutables)
;; "define" all methods with lazy tokens:
(let loop ([ms lazys]
[l pub-defines+pub-mutables]) ; longer than ms
(unless (null? ms)
(let ([m (car ms)])
(set-box! (car l) m))
(loop (cdr ms) (cdr l))))))))
(box 0)
(list struct:prim prop:dispatch methods))])
(set-box! prim-side-box c)
c))
(define-struct (exn:object exn) ())
(define (obj-error where . msg)
(raise
(make-exn:object
(string-append
(format "~a: " where)
(apply format msg))
(current-continuation-marks))))
(define (for-class name)
(if name (format " for class: ~a" name) ""))
(define (for-intf name)
(if name (format " for interface: ~a" name) ""))
(define (get-implement-requirement interfaces where for)
(let loop ([class #f]
[supers interfaces])
(if (null? supers)
class
(let ([c (interface-class (car supers))])
(loop
(cond
[(not c) class]
[(not class) c]
[(subclass? c class) class]
[(subclass? class c) c]
[else
(obj-error
where
"conflicting class implementation requirements in superinterfaces~a"
for)])
(cdr supers))))))
(define (compose-class name super interfaces
use-pre-ids ;; rename
use-final-ids ;; inherit
replace-ids ;; override
new-ids ;; public
go go-arity
primitive)
(unless (class? super)
(obj-error 'class*/names "superclass expression returned a non-class: ~a~a"
super
(for-class name)))
(let ([name (or name
(let ([s (class-name super)])
(and s
(not (eq? super object%))
(if (symbol? s)
(format "derived-from-~a" s)
s))))])
(for-each
(lambda (intf)
(unless (interface? intf)
(obj-error 'class*/names "interface expression returned a non-interface: ~a~a"
intf
(for-class name))))
interfaces)
(let ([ht (make-hash-table)]
[super-public-ids (class-public-ids super)])
;; Put superclass ids in table, with pos
(let loop ([ids super-public-ids][p 0])
(unless (null? ids)
(hash-table-put! ht (car ids) p)
(loop (cdr ids) (add1 p))))
;; Put new ids in table, with pos
(let loop ([ids new-ids][p (class-width super)])
(unless (null? ids)
(when (hash-table-get ht (car ids) (lambda () #f))
(obj-error 'class*/names "superclass already contains ivar: ~a~a"
(car ids)
(for-class name)))
(hash-table-put! ht (car ids) p)
(loop (cdr ids) (add1 p))))
;; Check that superclass has expected ids, and get indices
(let ([get-indices
(lambda (ids)
(map
(lambda (id)
(hash-table-get
ht id
(lambda ()
(obj-error 'class*/names
"superclass does not provide an expected ivar: ~a~a"
id
(for-class name)))))
ids))]
[width (+ (class-width super) (length new-ids))]
[prop:dispatch (or (and primitive (cadr primitive))
(class-prop:dispatch super))]
[methods (and primitive
(list->vector
(append (if (class-prim-methods super)
(vector->list (class-prim-methods super))
null)
(caddr primitive))))])
(let ([define-indices (get-indices (append replace-ids new-ids))]
[use-pre-indices (get-indices use-pre-ids)]
[use-final-indices (get-indices use-final-ids)]
[replace-indices (get-indices replace-ids)]
[new-indices (get-indices new-ids)]
[method-prim-vec (make-vector width (and primitive #t))])
;; Copy super's method prim flags:
(let ([svec (class-method-prim-vec super)])
(let loop ([i (class-width super)])
(unless (zero? i)
(let ([i (sub1 i)])
(vector-set! method-prim-vec i (vector-ref svec i))
(loop i)))))
;; If not prim, set prim-method flag for overridings
(unless primitive
(for-each (lambda (i)
(vector-set! method-prim-vec i #f))
replace-indices))
;; Check here that all interface ivars are satisfied
(for-each
(lambda (intf)
(for-each
(lambda (var)
(unless (hash-table-get ht var (lambda () #f))
(obj-error 'class*/names
"interface-required variable missing: ~a~a~a"
var
(for-class name)
(for-intf (interface-name intf)))))
(interface-public-ids intf)))
interfaces)
(let ([c (get-implement-requirement interfaces 'class*/names (for-class name))])
(when (and c (not (subclass? super c)))
(obj-error 'class*/names
"interface-required implementation not satisfied~a~a"
(for-class name)
(let ([r (class-name c)])
(if r
(format " required class: ~a" r)
"")))))
;; Make the class and its interface
(let* ([class-make (if name
(make-naming-constructor
struct:class
(string->symbol (format "class:~a" name)))
make-class)]
[interface-make (if name
(make-naming-constructor
struct:interface
(string->symbol (format "interface:~a" name)))
make-interface)]
[public-ids (append super-public-ids new-ids)]
[super-interfaces (cons (class-interface super) interfaces)]
[i (interface-make name super-interfaces public-ids #f)]
[struct:prim (or (and primitive (car primitive))
(class-struct:prim super))]
[c (class-make name
'object-make 'object-slot-ref 'object-slot-set!
width method-prim-vec
(add1 (class-pos super))
(list->vector (append (vector->list (class-supers super)) (list #f)))
i
ht public-ids
use-pre-indices ;; rename
define-indices ;; override, public
replace-indices ;; override
(append use-final-indices replace-indices new-indices) ;; inherit, override, public
go (if (box? go-arity)
(make-arity-at-least (unbox go-arity))
go-arity)
struct:prim prop:dispatch methods
(and primitive #t))]
[obj-name (if name
(string->symbol (format "object:~a" name))
'object)])
(let-values ([(struct:object object-make object-slot-ref object-slot-set!)
(let-values ([(t make p a m)
(make-struct-type obj-name
(or struct:prim #f)
0 ;; No init fields
;; Unless prim, add uninit fields for slots:
(if primitive
0
width)
'uninitialized-slot ;; anything for uninit val
(append
(if (and struct:prim (not primitive))
;; Need dispatcher
(list (cons prop:dispatch
(lambda (ivar-name)
(let ([pos (hash-table-get ht ivar-name)])
(if (vector-ref method-prim-vec pos)
#f
(lambda (o . args)
(apply (slot-ref o pos) args)))))))
null)
;; Add/override backbox:
(list
(cons prop:object (box #f))))
insp)])
(values t
make
(if primitive
;; No slots - selector always manufactures a value
(lambda (o p)
(box (lambda r (apply (vector-ref methods p) o r))))
;; Normal object slots:
a)
m))])
(set-box! (object-ref struct:object) c)
(set-class-object-make! c object-make)
(set-class-object-slot-ref! c object-slot-ref)
(set-class-object-slot-set!! c object-slot-set!)
(vector-set! (class-supers c) (class-pos c) c)
(set-interface-class! i c)
c)))))))
(define (compose-interface name supers vars)
(for-each
(lambda (intf)
(unless (interface? intf)
(obj-error 'interface
"superinterface expression returned a non-interface: ~a~a"
intf
(for-intf name))))
supers)
(let ([ht (make-hash-table)])
(for-each
(lambda (var)
(hash-table-put! ht var #t))
vars)
;; Check that vars don't already exist in supers:
(for-each
(lambda (super)
(for-each
(lambda (var)
(when (hash-table-get ht var (lambda () #f))
(obj-error 'interface "variable already in superinterface: ~a~a~a"
var
(for-intf name)
(let ([r (interface-name super)])
(if r
(format " already in: ~a" r)
"")))))
(interface-public-ids super)))
supers)
;; Check for [conflicting] implementation requirements
(let ([class (get-implement-requirement supers 'interface (for-intf name))]
[interface-make (if name
(make-naming-constructor
struct:interface
(string->symbol (format "interface:~a" name)))
make-interface)])
;; Add supervars to table:
(for-each
(lambda (super)
(for-each
(lambda (var) (hash-table-put! ht var #t))
(interface-public-ids super)))
supers)
;; Done
(interface-make name supers (hash-table-map ht (lambda (k v) k)) class))))
(define (make-object c . args)
(unless (class? c)
(apply raise-type-error 'make-object "class" 0 c args))
(let ([this ((class-object-make c))])
(let ([slot-ref (class-object-slot-ref c)]
[slot-set! (class-object-slot-set! c)]
[making-prim? (class-immediate-primitive? c)])
(unless (class-immediate-primitive? c)
(let loop ([n (class-width c)])
(unless (= n 0)
(slot-set! this (sub1 n) (box undefined))
(loop (sub1 n)))))
(let ([setup (let setup-class ([c c])
(if (zero? (class-pos c))
(lambda ()
((class-go c)))
(let ([super (vector-ref (class-supers c)
(sub1 (class-pos c)))])
(let ([super-setup (setup-class super)])
(let ([old-boxes (map (lambda (i)
(slot-ref this i))
(class-init-old-indices c))])
(for-each (lambda (i)
(slot-set! this i (box undefined)))
(if making-prim?
null
(class-replace-indices c)))
(let ([define-boxes (map (lambda (i)
(slot-ref this i))
(if making-prim?
null
(class-init-define-indices c)))])
(lambda ()
(let ([new-boxes (map (lambda (i)
(slot-ref this i))
(if making-prim?
null
(class-init-new-indices c)))]
[super-init (super-setup)]
[super-called? #f])
(letrec ([init (apply
(class-go c)
this
(lambda args
(when super-called?
(obj-error (or (object-name init)
'object-init)
"multiple intializations of superclass"))
(set! super-called? #t)
(apply super-init args)
;; Force lazy method boxes that might be used directly:
(when (and (class-struct:prim c)
(not (class-immediate-primitive? c)))
(for-each (lambda (b) (unbox/prim-resolve b this)) old-boxes)
(for-each (lambda (b) (unbox/prim-resolve b this)) new-boxes)))
(append
define-boxes ;; override, public
old-boxes ;; rename
new-boxes))]) ;; inherit, override, public
(lambda args
(apply init args)
(unless super-called?
(obj-error
(or (object-name init)
'object-init)
"initialization did not invoke superclass initializer"))))))))))))])
(apply (setup) args)
this))))
(define (is-a? v c)
(cond
[(class? c)
(and (object? v)
(subclass? (obj-class v) c))]
[(interface? c)
(and (object? v)
(implementation? (obj-class v) c))]
[else (raise-type-error 'is-a? "class or interface" 1 v c)]))
(define (subclass? v c)
(unless (class? c)
(raise-type-error 'subclass? "class" 1 v c))
(and (class? v)
(let ([p (class-pos c)])
(and (<= p (class-pos v))
(eq? c (vector-ref (class-supers v) p))))))
(define class->interface class-interface)
(define (object-interface o) (class-interface (obj-class o)))
(define (implementation? v i)
(unless (interface? i)
(raise-type-error 'implementation? "interface" 1 v i))
(and (class? v)
(interface-extension? (class->interface v) i)))
(define (interface-extension? v i)
(unless (interface? i)
(raise-type-error 'interface-extension? "interface" 1 v i))
(and (interface? i)
(let loop ([v v])
(or (eq? v i)
(ormap loop (interface-supers v))))))
(define (ivar-in-interface? s i)
(unless (symbol? s)
(raise-type-error 'ivar-in-interface? "symbol" 0 s i))
(unless (interface? i)
(raise-type-error 'ivar-in-interface? "interface" 1 s i))
(and (memq s (interface-public-ids i)) #t))
(define (interface->ivar-names i)
(unless (interface? i)
(raise-type-error 'interface->ivar-names "interface" i))
; copy list
(map values (interface-public-ids i)))
(define (class-initialization-arity c)
(unless (class? c)
(raise-type-error 'class-initialization-arity "class" c))
(class-go-arity c))
(define (ivar/proc o n)
(unless (object? o)
(raise-type-error 'ivar/proc "object" 0 o n))
(let ([c (obj-class o)])
(let ([p (hash-table-get
(class-public-ht c)
n
(lambda () #f))])
(if p
(slot-ref o p)
(begin
(unless (symbol? n)
(raise-type-error 'ivar/proc "symbol" 1 o n))
(obj-error 'ivar
"instance variable not found: ~e~a in: ~e"
n
(for-class (class-name c))
o))))))
(define-syntax ivar
(lambda (stx)
(syntax-case stx ()
[(_ o m)
(identifier? (syntax m))
(syntax (ivar/proc o 'm))])))
(define-syntax send
(lambda (stx)
(syntax-case stx ()
[(_ o m arg ...)
(identifier? (syntax m))
(syntax ((ivar o m) arg ...))])))
(define-syntax send*
(lambda (stx)
(syntax-case stx ()
[(_ obj (meth arg ...) ...)
(syntax/loc stx
(let ([o obj])
(send o meth arg ...)
...))])))
(define (make-generic/proc c n)
(unless (or (class? c) (interface? c))
(raise-type-error 'make-generic "class or interface" 0 c n))
(unless (symbol? n)
(raise-type-error 'make-generic/proc "symbol" 1 c n))
(if (class? c)
(let ([p (hash-table-get
(class-public-ht c)
n
(lambda () #f))])
(if p
(lambda (o)
(unless (is-a? o c)
(let ([name (string->symbol (format "generic~a" (for-class (class-name c))))])
(if (object? o)
(obj-error name
"object not an instance of the generic's class: ~e"
o)
(raise-type-error
name
"object"
o))))
(slot-ref o p))
(obj-error 'make-generic
"instance variable not found: ~e~a"
n
(for-class (class-name c)))))
(begin
(unless (memq n (interface-public-ids c))
(obj-error 'make-generic
"instance variable not found: ~e~a"
n
(for-intf (interface-name c))))
(lambda (o)
(unless (is-a? o c)
(let ([name (string->symbol (format "generic~a" (for-intf (interface-name c))))])
(if (object? o)
(obj-error name
"object not an instance of the generic's interface: ~e"
o)
(raise-type-error
name
"object"
o))))
(ivar/proc o n)))))
(define-syntax make-generic
(lambda (stx)
(syntax-case stx ()
[(_ c n)
(identifier? (syntax n))
(syntax
(make-generic/proc c 'n))])))
(define needs-init (gensym))
(define-syntax class*/names
(lambda (stx)
(syntax-case stx ()
[(_ (this-id super-init-id)
super-expr
(interface-expr ...)
init-vars
clauses ...)
(let ([se (lambda (msg expr)
(raise-syntax-error #f msg stx expr))])
;; Check this and super-init:
(unless (identifier? (syntax this-id))
(se "not an identifier" (syntax this-id)))
(unless (identifier? (syntax super-init-id))
(se "not an identifier" (syntax super-init-id)))
;; Unpack init arguments, with default expressions:
(let-values ([(init-ids init-defs init-rest-id)
(let loop ([inits (syntax init-vars)][need-def? #f])
(syntax-case inits ()
[() (values null null #f)]
[id (identifier? (syntax id))
(values null null (syntax id))]
[(id . rest) (identifier? (syntax id))
(begin
(when need-def?
(se "expected identifier with default value" (syntax id)))
(let-values ([(ids defs rest) (loop (syntax rest) #f)])
(values (cons (syntax id) ids)
(cons #f defs)
rest)))]
[((id def) . rest) (identifier? (syntax id))
(let-values ([(ids defs rest) (loop (syntax rest) #f)])
(values (cons (syntax id) ids)
(cons (syntax def) defs)
rest))]
[(first . rest)
(se "bad initialization declaration" (syntax first))]
[else (se "improper identifier list" (syntax init-vars))]))])
;; Unpack all body clauses:
(let* ([extract-ivars
;; Unpacks a public, private, or override clause
(lambda (kind can-rename? decls)
(map
(lambda (decl)
(syntax-case decl ()
[id (identifier? (syntax id))
(list kind (syntax id) (syntax id) (syntax (void)))]
[(id expr) (identifier? (syntax id))
(list kind (syntax id) (syntax id) (syntax expr))]
[(id) (and can-rename? (identifier? (syntax id)))
(list kind (syntax id) (syntax id) (syntax (void)))]
[((iid eid) expr) (and can-rename?
(identifier? (syntax iid))
(identifier? (syntax eid)))
(list kind (syntax iid) (syntax eid) (syntax expr))]
[else (se (format "bad ~a clause" kind) (syntax decl))]))
(syntax->list decls)))]
[body
;; Make a list of normalized clause-like lists, e.g:
;; (list (list 'public internal-id extenal-id expr) ...)
(apply
append
(map
(lambda (clause)
(syntax-case clause (public override private rename inherit sequence)
[(public decl ...)
(extract-ivars 'public #t (syntax (decl ...)))]
[(override decl ...)
(extract-ivars 'override #t (syntax (decl ...)))]
[(private decl ...)
(extract-ivars 'private #f (syntax (decl ...)))]
[(rename (iid eid) ...)
(let ([iids (syntax->list (syntax (iid ...)))]
[eids (syntax->list (syntax (eid ...)))])
(for-each (lambda (s)
(unless (identifier? s)
(se "expected an identifier" s)))
(append iids eids))
(map (lambda (iid eid)
(list 'rename iid eid))
iids eids))]
[(inherit id ...)
(map
(lambda (decl)
(syntax-case decl ()
[id (identifier? (syntax id))
(list 'inherit (syntax id) (syntax id))]
[(iid eid) (and (identifier? (syntax iid))
(identifier? (syntax eid)))
(list 'inherit (syntax iid) (syntax eid))]
[else (se "bad inherit clause" decl)]))
(syntax->list (syntax (id ...))))]
[(sequence expr ...)
(map
(lambda (expr)
(list 'sequence expr))
(syntax->list (syntax (expr ...))))]
[else (se "not a class clause" clause)]))
(syntax->list (syntax (clauses ...)))))]
[get-info (lambda (tags select)
(let loop ([body body])
(cond
[(null? body) null]
[(memq (caar body) tags)
(cons (select (car body)) (loop (cdr body)))]
[else (loop (cdr body))])))])
;; Extract internal and external ids, and create xformed body:
(let ([new-eids (get-info '(public) caddr)]
[use-pre-eids (get-info '(rename) caddr)]
[use-final-eids (get-info '(inherit) caddr)]
[replace-eids (get-info '(override) caddr)]
[inherited-ids (get-info '(inherit rename) cadr)]
[public-ids (get-info '(public override) cadr)]
[private-ids (get-info '(private) cadr)]
[immutable-boxed-ids (append (get-info '(rename) cadr) ;; order matters!
(get-info '(inherit) cadr))]
[mutable-boxed-ids (append (get-info '(override) cadr) ;; order matters!
(get-info '(public) cadr))])
(let* ([define-eids (append replace-eids new-eids)]
[define-iids (generate-temporaries define-eids)]
[body-exprs
(map
;; Map each declaration clause to a set!:
(lambda (clause)
(if (eq? (car clause) 'sequence)
(cadr clause)
(with-syntax ([id (cadr clause)]
[expr (cadddr clause)])
(if (memq (car clause) '(public override))
(let ([eid (caddr clause)])
(with-syntax ([nid (let loop ([de define-eids]
[di define-iids])
(if (eq? eid (car de))
(car di)
(loop (cdr de) (cdr di))))])
;; let sets name for expr:
(syntax (set-box! nid (let ([id expr]) id)))))
(syntax (set! id expr))))))
(get-info '(public override private sequence) values))]
[name (syntax-local-infer-name stx)])
;; Check for duplicates:
(cond
[(check-duplicate-identifier
(append new-eids use-final-eids replace-eids))
=> (lambda (name)
(se "duplicate declaration of external name" name))]
[(check-duplicate-identifier
(append init-ids (if init-rest-id (list init-rest-id) null)
public-ids inherited-ids private-ids))
=> (lambda (name)
(se "duplicate declaration of identifier" name))]
[else (void)])
;; ---------- build the result ----------
;; References to non-private ivars are converted to box
;; references.
(with-syntax ([use-pre-eids use-pre-eids]
[use-final-eids use-final-eids]
[replace-eids replace-eids]
[new-eids new-eids]
[define-eids define-eids]
[(define-iid ...) define-iids]
[(immutable-box-id ...) (generate-temporaries immutable-boxed-ids)]
[(mutable-box-id ...) (generate-temporaries mutable-boxed-ids)]
[(immutable-boxed-id ...) immutable-boxed-ids]
[(mutable-boxed-id ...) mutable-boxed-ids]
[(private-id ...) private-ids]
[body-exprs (if (null? body-exprs)
(syntax ((void)))
body-exprs)]
[init (datum->syntax-object
#f
(if name
(string->symbol (format "~a-init" name))
'init)
#f)]
[name (datum->syntax-object #f name #f)])
(with-syntax ([go
;; Create a sequence of case-lambda
;; clauses, to implement init variable defaults:
(let loop ([vars-so-far null]
[vars-w/def-so-far null]
[def-so-far null]
[init-ids init-ids]
[init-defs init-defs])
(cond
[(null? init-ids)
(with-syntax ([(var ...) (reverse vars-so-far)]
[(maybe-inited ...) (generate-temporaries vars-w/def-so-far)]
[(dvar ...) (reverse vars-w/def-so-far)]
[(def ...) (reverse def-so-far)]
[rest-id (if init-rest-id
init-rest-id
null)])
(syntax
([(var ... maybe-inited ... . rest-id)
(let ([dvar undefined] ...)
(set! dvar (if (eq? maybe-inited needs-init)
def
maybe-inited)) ...
.
body-exprs)])))]
[else
(with-syntax ([rest (loop (if (car init-defs)
vars-so-far
(cons (car init-ids) vars-so-far))
(if (car init-defs)
(cons (car init-ids) vars-w/def-so-far)
null)
(if (car init-defs)
(cons (car init-defs) def-so-far)
null)
(cdr init-ids)
(cdr init-defs))])
(if (car init-defs)
(with-syntax ([(var ...) (reverse vars-so-far)]
[(wd-var ...) (reverse vars-w/def-so-far)])
(syntax ([(var ... wd-var ...) (init var ... wd-var ... needs-init)]
. rest)))
(syntax rest)))]))]
[go-arity (datum->syntax-object
#f
(let ([req (let loop ([l init-defs][c 0])
(if (or (null? l) (car l))
c
(loop (cdr l) (add1 c))))]
[cnt (length init-ids)])
(cond
[init-rest-id
(box req)]
[(< req cnt)
(let loop ([req req])
(if (= req cnt)
(list req)
(cons req (loop (add1 req)))))]
[else req]))
#f)])
;; Assemble the result as a `compose-class-info' call,
;; which does all the run-time checks, and knows how
;; to allocate objects and pass boxes to the init
;; function.
(syntax/loc
stx
(compose-class
'name
super-expr
(list interface-expr ...)
'use-pre-eids ;; rename
'use-final-eids ;; inherit
'replace-eids ;; override
'new-eids ;; public
(lambda (this-id super-init-id
define-iid ... ;; override, public
immutable-box-id ... ;; rename, inherit
mutable-box-id ...) ;; override, public
(let-syntax ([immutable-boxed-id
(make-set!-transformer
(lambda (stx)
(syntax-case stx (set!)
[vr (identifier? (syntax vr))
(syntax (unbox immutable-box-id))]
[(set! vr val)
(raise-syntax-error
#f
"cannot mutate an inherit or rename variable"
stx)]
[(vr . args) (syntax ((unbox immutable-box-id) . args))])))]
...
[mutable-boxed-id
(make-set!-transformer
(lambda (stx)
(syntax-case stx (set!)
[vr (identifier? (syntax vr))
(syntax (unbox mutable-box-id))]
[(set! vr val)
(syntax
(set-box! mutable-box-id
;; let vr gives val the right name
(let ([vr val]) vr)))]
[(vr . args) (syntax ((unbox mutable-box-id) . args))])))]
...)
(let ([private-id undefined] ...)
(letrec ([init (case-lambda . go)])
init))))
'go-arity
#f)))))))))]
;; Error cases
;; --
[(_ bad-this-super
super-expr
(interface-expr ...)
init-vars
clauses ...)
(raise-syntax-error
#f
"bad this and super bindings"
stx
(syntax bad-this-super))]
;; --
[(_ this-super
super-expr
bad-interface-seq
init-vars
clauses ...)
(raise-syntax-error
#f
"expected sequence of interface expressions"
stx
(syntax bad-interface-seq))]
;;
[(_ this-super
super-expr
interface-seq)
(raise-syntax-error
#f
"missing initialization arguments"
stx
(syntax bad-this-super))]
[(_ this-super
super-expr)
(raise-syntax-error
#f
"missing interface expressions"
stx
(syntax bad-this-super))]
[(_ this-super)
(raise-syntax-error
#f
"missing this and super-init bindings"
stx
(syntax bad-this-super))])))
(define-syntax class*
(lambda (stx)
(syntax-case stx ()
[(_ super-expr
(interface-expr ...)
init-vars
clauses ...)
(with-syntax ([this (datum->syntax-object (stx-car stx) 'this stx)]
[super-init (datum->syntax-object (stx-car stx) 'super-init stx)])
(syntax/loc
stx
(class*/names (this super-init)
super-expr
(interface-expr ...)
init-vars
clauses ...)))])))
(define-syntax :class
(lambda (stx)
(syntax-case stx ()
[(_ super-expr
init-vars
clauses ...)
(with-syntax ([class* (datum->syntax-object (stx-car stx) 'class* stx)])
(syntax/loc stx (class* super-expr () init-vars clauses ...)))])))
(define-syntax class*-asi
(lambda (stx)
(syntax-case stx ()
[(_ super (interface ...) body ...)
(syntax/loc stx (class* super (interface ...) args
body ...))])))
(define-syntax class-asi
(lambda (stx)
(syntax-case stx ()
[(_ super body ...)
(syntax/loc stx (class* super () args
body ...))])))
(define-syntax :interface
(lambda (stx)
(syntax-case stx ()
[(_ (interface-expr ...) var ...)
(let ([vars (syntax->list (syntax (var ...)))]
[name (syntax-local-infer-name stx)])
(for-each
(lambda (v)
(unless (identifier? v)
(raise-syntax-error #f
"not an identifier"
stx
v)))
vars)
(let ([dup (check-duplicate-identifier vars)])
(when dup
(raise-syntax-error #f
"duplicate name"
stx
dup)))
(with-syntax ([name (datum->syntax-object #f name #f)])
(syntax/loc
stx
(compose-interface
'name
(list interface-expr ...)
'(var ...)))))])))
(provide (rename :class class) class* class*/names
class-asi class*-asi
(rename :interface interface)
make-object object? is-a? subclass? class? interface?
class->interface object-interface
implementation? interface-extension?
ivar-in-interface? interface->ivar-names
class-initialization-arity
ivar send send* make-generic
ivar/proc make-generic/proc
object% ;; object<%>
exn:object? struct:exn:object make-exn:object
prop:object make-prim-class))