2010-m1s1-compilation/lisp/squash-lisp-3.lisp
2011-01-13 00:00:49 +01:00

297 lines
13 KiB
Common Lisp

(require 'match "match")
(defun squash-lisp-3-internal (expr globals &optional (local-env (cons nil nil)) (getset (cons nil nil)) (top-level (cons nil nil)))
"Lorsqu'une variable à l'intérieur d'une `lambda' référence une déclaration à l'extérieur de la `lambda', on la marque comme étant *capturée*.
On fusionne tous les `let' d'une `lambda' en les remontant dans un `let' unique à la racine de la `lamdba'.
[Abandonné, fait dans la compilation] On fusionne tous les `tagbody' d'une `lambda' en les remontant dans un `tagbody' unique à la
racine de la `lambda' ? + transformation des if en tagbody.
On sort toutes les lambdas (fonctions anonymes), on les nomme avec un symbole unique, et on les met au top-level.
local-env : car = variables locales, cdr = variables capturées."
(macrolet ((transform (expr &optional (local-env 'local-env)) `(squash-lisp-3-internal ,expr globals ,local-env getset top-level)))
(cond-match
expr
;; simple-tagbody est équivalent à un progn, mais nécessaire pour les macrolet.
((:type (? (member x '(progn simple-tagbody))) :body _*)
(let ((res (list 'progn))
(is-tagbody (eq type 'simple-tagbody)))
(labels ((squash-progn (body)
(dolist (e body)
(if (and (consp e) (eq 'progn (car e)))
(squash-progn (cdr e))
(if (and (consp e) (eq 'simple-tagbody (car e)))
(progn (setq is-tagbody t)
(squash-progn (cdr e)))
(push e res))))))
(squash-progn (mapcar (lambda (x) (transform x)) body)))
;; TODO : ici : filtrer les expressions de `res' qui sont sans effet de bord, sauf la dernière.
(setq res (reverse res))
(setq res (append (remove ''nil (butlast res) :test #'equal) (last res)))
(setq res (if (cdr res) ;; res != '(progn)
(if (cddr res) ;; res != '(progn single-expr)
res
(cadr res))
'(quote nil)))
(when is-tagbody (setf (car res) 'simple-tagbody))
res))
((if :condition _ :si-vrai _ :si-faux _)
`(if ,(transform condition)
,(transform si-vrai)
,(transform si-faux)))
((unwind-protect :body _ :cleanup _)
`(unwind-protect ,(transform body)
,(transform cleanup)))
;; tagbody-unwind-catch est équivalent à unwind-catch, mais nécessaire pour les macrolet.
((:type (? (member x '(unwind-catch tagbody-unwind-catch))) :object _ :body (progn _*) :catch-code _)
`(,type ,(transform object)
,(transform body)
,(transform catch-code)))
((unwind :object _)
`(unwind ,(transform object)))
((unwind-for-tagbody :object _ :post-unwind-code _)
`(unwind-for-tagbody ,(transform object)
,(transform post-unwind-code)))
((jump-label :name $$)
expr)
((jump :dest $$)
expr)
((let :vars ($$*) :body _)
(setf (car local-env) (append vars (car local-env)))
(dolist (v vars)
(when (assoc v (car getset))
(error "squash-lisp-3-internal : Assertion failed ! Duplicate definition of ~w" v))
(push (cons v (cons nil nil)) (car getset)))
(transform body))
((named-lambda :name $$ :params (&rest :params-sym $$) :unused _ :body (let ($$*) _*))
(let* ((closure-sym (derived-symbol "CLOSURE"))
(new-local-env (progn (push (cons params-sym (cons nil nil)) (car getset))
(push (cons closure-sym (cons nil nil)) (car getset))
(cons (list closure-sym params-sym) nil)))
(tbody (transform body new-local-env))
(transitive-captures nil)
(here-captures nil))
;; on "nomme" la lambda, et ce nom est global
(push name (car globals))
;; on transforme les get-var de variables capturées en get-captured-var
(dolist (cap (cdr new-local-env))
(unless (or (member cap here-captures) (member cap transitive-captures))
(if (member cap (car new-local-env))
(let ((gs (assoc cap (car getset))))
(unless gs (error "squash-lisp-3-internal : Assertion failed ! ~w is captured, but not in getset." cap))
(dolist (getter (cadr gs))
(setf (car getter) 'get-captured-var))
(dolist (setter (cddr gs))
(setf (car setter) 'set-captured-var))
(push cap here-captures))
(progn
(push cap (cdr local-env))
(push cap transitive-captures)))))
;; on construit la lambda au top-level
(push `(set ',name (lambda (,closure-sym &rest ,params-sym) (get-var ,closure-sym) ,unused
(let (,@(remove closure-sym (remove params-sym (car new-local-env)))
,@transitive-captures)
(progn
,@(mapcar (lambda (x) `(make-captured-var ,x)) here-captures)
,@(loop for x in transitive-captures
collect `(setq ,x (funcall (fdefinition 'car) (get-var ,closure-sym)))
collect `(setq ,closure-sym (funcall (fdefinition 'cdr) (get-var ,closure-sym))))
,tbody))))
(car top-level))
;; on remplace toute la lambda par un accès à sa définition au top-level
`(make-closure ,name ,@transitive-captures)))
((funcall :fun _ :params _*)
`(funcall ,@(mapcar (lambda (x) (transform x)) (cons fun params))))
((quote _)
expr)
((get-var :name $$)
(if (member name (car globals))
expr
(let ((getter (list 'get-var name))
(assoc (assoc name (car getset))))
(unless (member name (car local-env))
(pushnew name (cdr local-env)))
(unless assoc
(error "squash-lisp-3-internal : Assertion failed ! ~w used as local but not in getset alist." name))
(push getter (cadr assoc))
getter)))
((setq :name $$ :value _)
(if (member name (car globals))
expr
(let ((setter (list 'setq name (transform value)))
(assoc (assoc name (car getset))))
(unless (member name (car local-env))
(pushnew name (cdr local-env)))
(unless assoc
(error "squash-lisp-3-internal : Assertion failed ! ~w used as local but not in getset alist." name))
(push setter (cddr assoc))
setter)))
((fdefinition (quote $$))
expr)
((symbol-value (quote $$))
expr)
((set (quote :var $$) :value _)
`(set ',var ,(transform value)))
(_
(error "squash-lisp-3-internal : Assertion failed ! this should not be here : ~w" expr)))))
(defun squash-lisp-3 (expr globals)
(let* ((tl (cons nil nil))
(lsym (make-symbol "MAIN"))
(psym (make-symbol "NO-PARAMETERS")))
(squash-lisp-3-internal `(named-lambda ,lsym (&rest ,psym) (get-var ,psym) (let () ,expr)) globals (cons nil nil) (cons nil nil) tl)
`(top-level ,lsym ,globals (progn ,@(reverse (car tl))))))
(defun squash-lisp-3-check-2 (expr)
"Vérifie si expr est bien un résultat valable de squash-lisp-1.
Permet aussi d'avoir une «grammaire» du simple-lisp niveau 1.
Attention : il y a quelques invariants qui ne sont pas présents dans cette vérification."
(cond-match
expr
;; simple-tagbody est équivalent à un progn, mais nécessaire pour les macrolet.
(((? (member x '(progn simple-tagbody))) :body _*)
(every #'squash-lisp-3-check-2 body))
((if :condition _ :si-vrai _ :si-faux _)
(and (squash-lisp-3-check-2 condition)
(squash-lisp-3-check-2 si-vrai)
(squash-lisp-3-check-2 si-faux)))
((unwind-protect :body _ :cleanup _)
(and (squash-lisp-3-check-2 body)
(squash-lisp-3-check-2 cleanup)))
;; tagbody-unwind-catch est équivalent à unwind-catch, mais nécessaire pour les macrolet.
(((? (member x '(unwind-catch tagbody-unwind-catch))) :object _ :body (progn _*) :catch-code _)
(and (squash-lisp-3-check-2 object)
(squash-lisp-3-check-2 body)
(squash-lisp-3-check-2 catch-code)))
((unwind :object _)
(squash-lisp-3-check-2 object))
((unwind-for-tagbody :object _ :post-unwind-code _)
(and (squash-lisp-3-check-2 object)
(squash-lisp-3-check-2 post-unwind-code)))
((jump-label :name $$)
t)
((jump :dest $$)
t)
;; ((let ($$*) :body _)
;; (squash-lisp-3-check-2 body))
;; ((lambda (&rest $$) :unused _ :body (let ($$*) _*))
;; (squash-lisp-3-check-2 body))
((funcall :fun _ :params _*)
(every #'squash-lisp-3-check-2 (cons fun params)))
((quote _)
t)
((get-var $$)
t)
((setq :name $$ :value _)
(squash-lisp-3-check-2 value))
((fdefinition (quote $$))
t)
((symbol-value (quote $$))
t)
((set (quote $$) :value _)
(squash-lisp-3-check-2 value))
((make-closure $$ $$*)
t)
((make-captured-var $$)
t)
((get-captured-var $$)
t)
((set-captured-var $$ :value _)
(squash-lisp-3-check-2 value))
(_
(warn "squash-lisp-3-check-2: Assertion failed ! This should not be here : ~w" expr)
nil)))
(defun squash-lisp-3-check-1 (expr)
(cond-match
expr
((set (quote $$) (lambda ($$ &rest $$) (get-var $$) (get-var $$) (let ($$*) :body _)))
(squash-lisp-3-check-2 body))
(_
(warn "~&squash-lisp-3-check : this should not be here :~&~w" expr)
nil)))
(defun squash-lisp-3-check (expr)
(cond-match expr
((top-level $$ (($$*) . ($$*)) (progn :body _*))
(every #'squash-lisp-3-check-1 body))
(_ (warn "~&squash-lisp-3-check : this should not be here :~&~w" expr)
nil)))
(defun nice-squash-lisp-3-check (expr)
(match (top-level $$ (($$*) . ($$*)) (progn (set '$$ (lambda ($$ &rest $$) (get-var $$) (get-var $$) (let ($$*) (? squash-lisp-3-check-2))))*))
expr))
(defun squash-lisp-1+3 (expr &optional (etat (list nil nil nil)))
(let ((globals (cons nil nil)))
(squash-lisp-3 (squash-lisp-1 expr t etat nil nil globals) globals)))
(defun squash-lisp-3-wrap (expr)
`(macrolet ((unwind-catch (object body catch-code)
(let ((bname (make-symbol "BLOCK")))
`(block ,bname
(catch ,object (return-from ,bname ,body))
,catch-code)))
(tagbody-unwind-catch (object body catch-code)
catch-code ;; unused variable
;; les (progn object) et (progn x) sert à permettre l'expansion des macros sur x
;; (il est possible qu'elles ne soient pas expansées à la racine du tagbody)
`(tagbody (progn ,object) ,@(mapcar (lambda (x) (if (eq (car x) 'jump-label) (cadr x) (progn x))) (cdr body))))
(simple-tagbody (&rest body)
`(tagbody ,@(mapcar (lambda (x) (if (eq (car x) 'jump-label) (cadr x) (progn x))) body)))
(unwind (object)
`(throw ,object nil))
(unwind-for-tagbody (object post-unwind-code)
object ;; unused variable
post-unwind-code)
(top-level (main globals body)
globals
`(progn
,body
(funcall ,main nil)))
(jump (dest)
`(go ,dest))
(get-var (x)
x)
(make-closure (fun &rest vars)
(let ((args-sym (make-symbol "AR")))
`(lambda (&rest ,args-sym)
(apply ,fun (list ,@vars) ,args-sym))))
(make-captured-var (x)
`(setq ,x (cons nil nil)))
(get-captured-var (x)
`(car ,x))
(set-captured-var (x v)
`(setf (car ,x) ,v)))
,expr))
(require 'test-unitaire "test-unitaire")
(erase-tests squash-lisp-3)
(deftest (squash-lisp-3 internal progn)
(squash-lisp-3-internal '(progn
(progn (progn) (progn))
(progn)
(progn (progn) (progn) (progn)))
'(nil . nil))
''nil)
(deftest (squash-lisp-3 internal progn)
(squash-lisp-3-internal '(progn) '(nil . nil))
''nil)
(deftest (squash-lisp-3 internal progn)
(squash-lisp-3-internal '(progn (symbol-value 'a)) '((a) . nil))
'(symbol-value 'a))
(deftest (squash-lisp-3 internal progn)
(squash-lisp-3-internal '(progn
(progn (progn (symbol-value 'a)) (progn))
(progn)
(progn (progn) (progn) (progn)))
'((a) . nil))
'(progn (symbol-value 'a) 'nil))
;(run-tests squash-lisp-3)