;;;; a simple code walker for PCL
;;;;
-;;;; The code which implements the macroexpansion environment manipulation
-;;;; mechanisms is in the first part of the file, the real walker follows it.
+;;;; The code which implements the macroexpansion environment
+;;;; manipulation mechanisms is in the first part of the file, the
+;;;; real walker follows it.
;;;; This software is part of the SBCL system. See the README file for
;;;; more information.
;;;; specification.
(in-package "SB-WALKER")
-
-(sb-int:file-comment
- "$Header$")
\f
-;;;; environment frobbing stuff
+;;;; environment hacking stuff, necessarily SBCL-specific
;;; Here in the original PCL were implementations of the
-;;; implementation-specific environment hacking functions for each of the
-;;; implementations this walker had been ported to. This functionality was
-;;; originally factored out in order to make PCL portable from one Common Lisp
-;;; to another. As of 19981107, that portability was fairly stale and (because
-;;; of the scarcity of CLTL1 implementations and the strong interdependence of
-;;; the rest of ANSI Common Lisp on the CLOS system) fairly irrelevant. It was
-;;; fairly thoroughly put out of its misery by WHN in his quest to clean up the
-;;; system enough that it can be built from scratch using any ANSI Common Lisp.
+;;; implementation-specific environment hacking functions for each of
+;;; the implementations this walker had been ported to. This
+;;; functionality was originally factored out in order to make PCL
+;;; portable from one Common Lisp to another. As of 19981107, that
+;;; portability was fairly stale and (because of the scarcity of CLTL1
+;;; implementations and the strong interdependence of the rest of ANSI
+;;; Common Lisp on the CLOS system) fairly irrelevant. It was fairly
+;;; thoroughly put out of its misery by WHN in his quest to clean up
+;;; the system enough that it can be built from scratch using any ANSI
+;;; Common Lisp.
;;;
-;;; This code just hacks 'macroexpansion environments'. That is, it is only
-;;; concerned with the function binding of symbols in the environment. The
-;;; walker needs to be able to tell if the symbol names a lexical macro or
-;;; function, and it needs to be able to build environments which contain
-;;; lexical macro or function bindings. It must be able, when walking a
-;;; MACROLET, FLET or LABELS form to construct an environment which reflects
-;;; the bindings created by that form. Note that the environment created
-;;; does NOT have to be sufficient to evaluate the body, merely to walk its
-;;; body. This means that definitions do not have to be supplied for lexical
-;;; functions, only the fact that that function is bound is important. For
-;;; macros, the macroexpansion function must be supplied.
+;;; This code just hacks 'macroexpansion environments'. That is, it is
+;;; only concerned with the function binding of symbols in the
+;;; environment. The walker needs to be able to tell if the symbol
+;;; names a lexical macro or function, and it needs to be able to
+;;; build environments which contain lexical macro or function
+;;; bindings. It must be able, when walking a MACROLET, FLET or LABELS
+;;; form to construct an environment which reflects the bindings
+;;; created by that form. Note that the environment created does NOT
+;;; have to be sufficient to evaluate the body, merely to walk its
+;;; body. This means that definitions do not have to be supplied for
+;;; lexical functions, only the fact that that function is bound is
+;;; important. For macros, the macroexpansion function must be
+;;; supplied.
;;;
-;;; This code is organized in a way that lets it work in implementations that
-;;; stack cons their environments. That is reflected in the fact that the
-;;; only operation that lets a user build a new environment is a WITH-BODY
-;;; macro which executes its body with the specified symbol bound to the new
-;;; environment. No code in this walker or in PCL will hold a pointer to
-;;; these environments after the body returns. Other user code is free to do
-;;; so in implementations where it works, but that code is not considered
-;;; portable.
+;;; This code is organized in a way that lets it work in
+;;; implementations that stack cons their environments. That is
+;;; reflected in the fact that the only operation that lets a user
+;;; build a new environment is a WITH-BODY macro which executes its
+;;; body with the specified symbol bound to the new environment. No
+;;; code in this walker or in PCL will hold a pointer to these
+;;; environments after the body returns. Other user code is free to do
+;;; so in implementations where it works, but that code is not
+;;; considered portable.
;;;
;;; There are 3 environment hacking tools. One macro,
-;;; WITH-AUGMENTED-ENVIRONMENT, which is used to create new environments, and
-;;; two functions, ENVIRONMENT-FUNCTION and ENVIRONMENT-MACRO, which are used
-;;; to access the bindings of existing environments
+;;; WITH-AUGMENTED-ENVIRONMENT, which is used to create new
+;;; environments, and two functions, ENVIRONMENT-FUNCTION and
+;;; ENVIRONMENT-MACRO, which are used to access the bindings of
+;;; existing environments
;;; In SBCL, as in CMU CL before it, the environment is represented
;;; with a structure that holds alists for the functional things,
-;;; variables, blocks, etc. Only the c::lexenv-functions slot is
-;;; relevant. It holds: Alist (name . what), where What is either a
-;;; Functional (a local function) or a list (MACRO . <function>) (a
+;;; variables, blocks, etc.
+;;; Except for SYMBOL-MACROLET, only the SB-C::LEXENV-FUNCTIONS slot
+;;; is relevant. It holds: Alist (Name . What), where What is either
+;;; a functional (a local function) or a list (MACRO . <function>) (a
;;; local macro, with the specifier expander.) Note that Name may be a
;;; (SETF <name>) function.
+;;; Accessors are defined below, eg (ENV-WALK-FUNCTION ENV).
+;;;
+;;; If WITH-AUGMENTED-ENVIRONMENT is called from WALKER-ENVIRONMENT-BIND
+;;; this code hides the WALKER version of an environment
+;;; inside the SB-C::LEXENV structure.
+;;;
+;;; In CMUCL (and former SBCL), This used to be a list of lists of form
+;;; (<gensym-name> MACRO . #<interpreted-function>) in the :functions slot
+;;; in a C::LEXENV.
+;;; This form was accepted by the compiler, but this was a crude hack,
+;;; because the <interpreted-function> was used as a structure to hold the
+;;; bits of interest, {function, form, declarations, lexical-variables},
+;;; a list, which was not really an interpreted function.
+;;; Instead this list was COERCEd to a #<FUNCTION ...>!
+;;;
+;;; Instead, we now use a special sort of "function"-type for that
+;;; information, because the functions slot in SB-C::LEXENV is
+;;; supposed to have a list of <Name MACRO . #<function> elements.
+;;; So, now we hide our bits of interest in the walker-info slot in
+;;; our new BOGO-FUNCTION.
+;;;
+;;; MACROEXPAND-1 is the only SBCL function that gets called with the
+;;; constructed environment argument.
+
+(/show "walk.lisp 108")
(defmacro with-augmented-environment
((new-env old-env &key functions macros) &body body)
,macros)))
,@body))
-;;; KLUDGE: In CMU CL, when X was an arbitrary list, even one which did
-;;; not name a function or describe a lambda expression, (EVAL
-;;; `(FUNCTION ,X)) would still return a FUNCTION object, and no error
-;;; would be signalled until/unless you tried to FUNCALL the resulting
-;;; FUNCTION object. (This behavior was also present in (COERCE X
-;;; 'FUNCTION), which was defined in terms of (EVAL `(FUNCTION ,X)).)
-;;; This function provides roughly the same behavior as the old CMU CL
-;;; (COERCE X 'FUNCTION), for the benefit of PCL code which relied
-;;; on being able to coerce bogus things without raising errors
-;;; as long as it never tried to actually call them.
-(defun bogo-coerce-to-function (x)
- (or (ignore-errors (coerce x 'function))
- (lambda (&rest rest)
- (declare (ignore rest))
- (error "can't FUNCALL bogo-coerced-to-function ~S" x))))
+;;; a unique tag to show that we're the intended caller of BOGO-FUNCTION
+(defvar *bogo-function-magic-tag*
+ '(:bogo-function-magic-tag))
+;;; The interface of BOGO-FUNCTIONs (previously implemented as
+;;; FUNCALLABLE-INSTANCES) is just these two operations, so we can
+;;; do them with ordinary closures.
+;;;
+;;; KLUDGE: BOGO-FUNCTIONS are sorta weird, and MNA and I have both
+;;; hacked on this code without really figuring out what they're for.
+;;; (He changed them to work after some changes in the IR1 interpreter
+;;; made functions not be built lazily, and I changed them so that
+;;; they don't need FUNCALLABLE-INSTANCE stuff, so that the F-I stuff
+;;; can become less general.) There may be further simplifications or
+;;; clarifications which could be done. -- WHN 2001-10-19
+(defun walker-info-to-bogo-function (walker-info)
+ (lambda (magic-tag &rest rest)
+ (aver (not rest)) ; else someone is using me in an unexpected way
+ (aver (eql magic-tag *bogo-function-magic-tag*)) ; else ditto
+ walker-info))
+(defun bogo-function-to-walker-info (bogo-function)
+ (declare (type function bogo-function))
+ (funcall bogo-function *bogo-function-magic-tag*))
+
(defun with-augmented-environment-internal (env functions macros)
;; Note: In order to record the correct function definition, we
;; would have to create an interpreted closure, but the
- ;; with-new-definition macro down below makes no distinction between
+ ;; WITH-NEW-DEFINITION macro down below makes no distinction between
;; FLET and LABELS, so we have no idea what to use for the
;; environment. So we just blow it off, 'cause anything real we do
- ;; would be wrong. We still have to make an entry so we can tell
+ ;; would be wrong. But we still have to make an entry so we can tell
;; functions from macros.
- (let ((env (or env (sb-kernel:make-null-lexenv))))
+ (let ((lexenv (sb-kernel::coerce-to-lexenv env)))
(sb-c::make-lexenv
- :default env
+ :default lexenv
:functions
(append (mapcar (lambda (f)
- (cons (car f) (sb-c::make-functional :lexenv env)))
+ (cons (car f) (sb-c::make-functional :lexenv lexenv)))
functions)
(mapcar (lambda (m)
(list* (car m)
'sb-c::macro
- (bogo-coerce-to-function (cadr m))))
- macros)))))
+ (if (eq (car m) *key-to-walker-environment*)
+ (walker-info-to-bogo-function (cadr m))
+ (coerce (cadr m) 'function))))
+ macros)))))
(defun environment-function (env fn)
(when env
(let ((entry (assoc macro (sb-c::lexenv-functions env) :test #'eq)))
(and entry
(eq (cadr entry) 'sb-c::macro)
- (function-lambda-expression (cddr entry))))))
+ (if (eq macro *key-to-walker-environment*)
+ (values (bogo-function-to-walker-info (cddr entry)))
+ (values (function-lambda-expression (cddr entry))))))))
+\f
+;;;; other environment hacking, not so SBCL-specific as the
+;;;; environment hacking in the previous section
(defmacro with-new-definition-in-environment
((new-env old-env macrolet/flet/labels-form) &body body)
(eval `(defmacro ,gensym ,llist ,@body))
(macro-function gensym)))
\f
-;;; Now comes the real walker.
-;;;
-;;; As the walker walks over the code, it communicates information to itself
-;;; about the walk. This information includes the walk function, variable
-;;; bindings, declarations in effect etc. This information is inherently
-;;; lexical, so the walker passes it around in the actual environment the
-;;; walker passes to macroexpansion functions. This is what makes the
-;;; nested-walk-form facility work properly.
+;;;; the actual walker
+
+;;; As the walker walks over the code, it communicates information to
+;;; itself about the walk. This information includes the walk
+;;; function, variable bindings, declarations in effect etc. This
+;;; information is inherently lexical, so the walker passes it around
+;;; in the actual environment the walker passes to macroexpansion
+;;; functions. This is what makes the NESTED-WALK-FORM facility work
+;;; properly.
(defmacro walker-environment-bind ((var env &rest key-args)
&body body)
`(with-augmented-environment
(defun note-lexical-binding (thing env)
(push (list thing :lexical-var) (cadddr (env-lock env))))
-(defun variable-lexical-p (var env)
+(defun var-lexical-p (var env)
(let ((entry (member var (env-lexical-variables env) :key #'car)))
(when (eq (cadar entry) :lexical-var)
entry)))
(when (eq (cadar entry) :macro)
entry)))
-(defvar *variable-declarations* '(special))
+(defvar *var-declarations* '(special))
-(defun variable-declaration (declaration var env)
- (if (not (member declaration *variable-declarations*))
+(defun var-declaration (declaration var env)
+ (if (not (member declaration *var-declarations*))
(error "~S is not a recognized variable declaration." declaration)
- (let ((id (or (variable-lexical-p var env) var)))
+ (let ((id (or (var-lexical-p var env) var)))
(dolist (decl (env-declarations env))
(when (and (eq (car decl) declaration)
(eq (cadr decl) id))
(return decl))))))
-(defun variable-special-p (var env)
- (or (not (null (variable-declaration 'special var env)))
- (variable-globally-special-p var)))
+(defun var-special-p (var env)
+ (or (not (null (var-declaration 'special var env)))
+ (var-globally-special-p var)))
-(defun variable-globally-special-p (symbol)
- (eq (sb-int:info :variable :kind symbol) :special))
+(defun var-globally-special-p (symbol)
+ (eq (info :variable :kind symbol) :special))
\f
;;;; handling of special forms
-;;; Here are some comments from the original PCL on the difficulty of doing
-;;; this portably across different CLTL1 implementations. This is no longer
-;;; directly relevant because this code now only runs on SBCL, but the comments
-;;; are retained for culture: they might help explain some of the design
-;;; decisions which were made in the code.
+;;; Here are some comments from the original PCL on the difficulty of
+;;; doing this portably across different CLTL1 implementations. This
+;;; is no longer directly relevant because this code now only runs on
+;;; SBCL, but the comments are retained for culture: they might help
+;;; explain some of the design decisions which were made in the code.
;;;
;;; and I quote...
;;;
;;; program needs no special knowledge about macros...
;;;
;;; So all we have to do here is a define a way to store and retrieve
-;;; templates which describe how to walk the 24 special forms and we are all
-;;; set...
+;;; templates which describe how to walk the 24 special forms and we
+;;; are all set...
;;;
-;;; Well, its a nice concept, and I have to admit to being naive enough that
-;;; I believed it for a while, but not everyone takes having only 24 special
-;;; forms as seriously as might be nice. There are (at least) 3 ways to
-;;; lose:
+;;; Well, its a nice concept, and I have to admit to being naive
+;;; enough that I believed it for a while, but not everyone takes
+;;; having only 24 special forms as seriously as might be nice. There
+;;; are (at least) 3 ways to lose:
;;
-;;; 1 - Implementation x implements a Common Lisp special form as a macro
-;;; which expands into a special form which:
+;;; 1 - Implementation x implements a Common Lisp special form as
+;;; a macro which expands into a special form which:
;;; - Is a common lisp special form (not likely)
;;; - Is not a common lisp special form (on the 3600 IF --> COND).
;;;
-;;; * We can safe ourselves from this case (second subcase really) by
-;;; checking to see whether there is a template defined for something
-;;; before we check to see whether we can macroexpand it.
+;;; * We can safe ourselves from this case (second subcase really)
+;;; by checking to see whether there is a template defined for
+;;; something before we check to see whether we can macroexpand it.
;;;
;;; 2 - Implementation x implements a Common Lisp macro as a special form.
;;;
;;; * This is a screw, but not so bad, we save ourselves from it by
;;; defining extra templates for the macros which are *likely* to
-;;; be implemented as special forms. (DO, DO* ...)
+;;; be implemented as special forms. [Note: As of sbcl-0.6.9, these
+;;; extra templates have been deleted, since this is not a problem
+;;; in SBCL and we no longer try to make this walker portable
+;;; across other possibly-broken CL implementations.]
;;;
;;; 3 - Implementation x has a special form which is not on the list of
;;; Common Lisp special forms.
;;;
-;;; * This is a bad sort of a screw and happens more than I would like
-;;; to think, especially in the implementations which provide more
-;;; than just Common Lisp (3600, Xerox etc.).
-;;; The fix is not terribly staisfactory, but will have to do for
+;;; * This is a bad sort of a screw and happens more than I would
+;;; like to think, especially in the implementations which provide
+;;; more than just Common Lisp (3600, Xerox etc.).
+;;; The fix is not terribly satisfactory, but will have to do for
;;; now. There is a hook in get walker-template which can get a
;;; template from the implementation's own walker. That template
;;; has to be converted, and so it may be that the right way to do
;;; interface to its walker which looks like the interface to this
;;; walker.
-;;; FIXME: In SBCL, we probably don't need to put DEFMACROs inside EVAL-WHEN.
-(eval-when (:compile-toplevel :load-toplevel :execute)
-
-(defmacro get-walker-template-internal (x) ;Has to be inside eval-when because
- `(get ,x 'walker-template)) ;Golden Common Lisp doesn't hack
- ;compile time definition of macros
- ;right for setf.
+(defmacro get-walker-template-internal (x)
+ `(get ,x 'walker-template))
(defmacro define-walker-template (name
&optional (template '(nil repeat (eval))))
`(eval-when (:load-toplevel :execute)
(setf (get-walker-template-internal ',name) ',template)))
-) ; EVAL-WHEN
-
(defun get-walker-template (x)
(cond ((symbolp x)
- (or (get-walker-template-internal x)
- (get-implementation-dependent-walker-template x)))
+ (get-walker-template-internal x))
((and (listp x) (eq (car x) 'lambda))
'(lambda repeat (eval)))
(t
(error "can't get template for ~S" x))))
-
-;;; FIXME: This can go away in SBCL.
-(defun get-implementation-dependent-walker-template (x)
- (declare (ignore x))
- ())
\f
;;;; the actual templates
;;; ANSI special forms
-(define-walker-template block (nil nil repeat (eval)))
-(define-walker-template catch (nil eval repeat (eval)))
-(define-walker-template declare walk-unexpected-declare)
-(define-walker-template eval-when (nil quote repeat (eval)))
-(define-walker-template flet walk-flet)
-(define-walker-template function (nil call))
-(define-walker-template go (nil quote))
-(define-walker-template if walk-if)
-(define-walker-template labels walk-labels)
-(define-walker-template lambda walk-lambda)
-(define-walker-template let walk-let)
-(define-walker-template let* walk-let*)
-(define-walker-template locally walk-locally)
-(define-walker-template macrolet walk-macrolet)
+(define-walker-template block (nil nil repeat (eval)))
+(define-walker-template catch (nil eval repeat (eval)))
+(define-walker-template declare walk-unexpected-declare)
+(define-walker-template eval-when (nil quote repeat (eval)))
+(define-walker-template flet walk-flet)
+(define-walker-template function (nil call))
+(define-walker-template go (nil quote))
+(define-walker-template if walk-if)
+(define-walker-template labels walk-labels)
+(define-walker-template lambda walk-lambda)
+(define-walker-template let walk-let)
+(define-walker-template let* walk-let*)
+(define-walker-template locally walk-locally)
+(define-walker-template macrolet walk-macrolet)
(define-walker-template multiple-value-call (nil eval repeat (eval)))
(define-walker-template multiple-value-prog1 (nil return repeat (eval)))
(define-walker-template multiple-value-setq walk-multiple-value-setq)
(define-walker-template multiple-value-bind walk-multiple-value-bind)
-(define-walker-template progn (nil repeat (eval)))
-(define-walker-template progv (nil eval eval repeat (eval)))
-(define-walker-template quote (nil quote))
-(define-walker-template return-from (nil quote repeat (return)))
-(define-walker-template setq walk-setq)
+(define-walker-template progn (nil repeat (eval)))
+(define-walker-template progv (nil eval eval repeat (eval)))
+(define-walker-template quote (nil quote))
+(define-walker-template return-from (nil quote repeat (return)))
+(define-walker-template setq walk-setq)
(define-walker-template symbol-macrolet walk-symbol-macrolet)
-(define-walker-template tagbody walk-tagbody)
-(define-walker-template the (nil quote eval))
-(define-walker-template throw (nil eval eval))
+(define-walker-template tagbody walk-tagbody)
+(define-walker-template the (nil quote eval))
+(define-walker-template throw (nil eval eval))
(define-walker-template unwind-protect (nil return repeat (eval)))
;;; SBCL-only special forms
-(define-walker-template sb-ext:truly-the (nil quote eval))
-
-;;; extra templates
-(define-walker-template do walk-do)
-(define-walker-template do* walk-do*)
-(define-walker-template prog walk-prog)
-(define-walker-template prog* walk-prog*)
-(define-walker-template cond (nil repeat ((test repeat (eval)))))
+(define-walker-template sb-ext:truly-the (nil quote eval))
\f
(defvar *walk-form-expand-macros-p* nil)
-(defun macroexpand-all (form &optional environment)
- (let ((*walk-form-expand-macros-p* t))
- (walk-form form environment)))
-
(defun walk-form (form
&optional environment
(walk-function
- #'(lambda (subform context env)
- (declare (ignore context env))
- subform)))
+ (lambda (subform context env)
+ (declare (ignore context env))
+ subform)))
(walker-environment-bind (new-env environment :walk-function walk-function)
(walk-form-internal form :eval new-env)))
-;;; NESTED-WALK-FORM provides an interface that allows nested macros, each
-;;; of which must walk their body, to just do one walk of the body of the
-;;; inner macro. That inner walk is done with a walk function which is the
-;;; composition of the two walk functions.
-;;;
-;;; This facility works by having the walker annotate the environment that
-;;; it passes to MACROEXPAND-1 to know which form is being macroexpanded.
-;;; If then the &WHOLE argument to the macroexpansion function is eq to
-;;; the ENV-WALK-FORM of the environment, NESTED-WALK-FORM can be certain
-;;; that there are no intervening layers and that a nested walk is OK.
-;;;
-;;; KLUDGE: There are some semantic problems with this facility. In particular,
-;;; if the outer walk function returns T as its WALK-NO-MORE-P value, this will
-;;; prevent the inner walk function from getting a chance to walk the subforms
-;;; of the form. This is almost never what you want, since it destroys the
-;;; equivalence between this NESTED-WALK-FORM function and two separate
-;;; WALK-FORMs.
-(defun nested-walk-form (whole form
- &optional environment
- (walk-function
- #'(lambda (subform context env)
- (declare (ignore context env))
- subform)))
- (if (eq whole (env-walk-form environment))
- (let ((outer-walk-function (env-walk-function environment)))
- (throw whole
- (walk-form
- form
- environment
- #'(lambda (f c e)
- ;; First loop to make sure the inner walk function
- ;; has done all it wants to do with this form.
- ;; Basically, what we are doing here is providing
- ;; the same contract walk-form-internal normally
- ;; provides to the inner walk function.
- (let ((inner-result nil)
- (inner-no-more-p nil)
- (outer-result nil)
- (outer-no-more-p nil))
- (loop
- (multiple-value-setq (inner-result inner-no-more-p)
- (funcall walk-function f c e))
- (cond (inner-no-more-p (return))
- ((not (eq inner-result f)))
- ((not (consp inner-result)) (return))
- ((get-walker-template (car inner-result)) (return))
- (t
- (multiple-value-bind (expansion macrop)
- (walker-environment-bind
- (new-env e :walk-form inner-result)
- (macroexpand-1 inner-result new-env))
- (if macrop
- (setq inner-result expansion)
- (return)))))
- (setq f inner-result))
- (multiple-value-setq (outer-result outer-no-more-p)
- (funcall outer-walk-function
- inner-result
- c
- e))
- (values outer-result
- (and inner-no-more-p outer-no-more-p)))))))
- (walk-form form environment walk-function)))
-
-;;; WALK-FORM-INTERNAL is the main driving function for the code walker. It
-;;; takes a form and the current context and walks the form calling itself or
-;;; the appropriate template recursively.
+;;; WALK-FORM-INTERNAL is the main driving function for the code
+;;; walker. It takes a form and the current context and walks the form
+;;; calling itself or the appropriate template recursively.
;;;
;;; "It is recommended that a program-analyzing-program process a form
;;; that is a list whose car is a symbol as follows:
;;;
;;; 1. If the program has particular knowledge about the symbol,
-;;; process the form using special-purpose code. All of the
-;;; standard special forms should fall into this category.
-;;; 2. Otherwise, if macro-function is true of the symbol apply
-;;; either macroexpand or macroexpand-1 and start over.
+;;; process the form using special-purpose code. All of the
+;;; standard special forms should fall into this category.
+;;; 2. Otherwise, if MACRO-FUNCTION is true of the symbol apply
+;;; either MACROEXPAND or MACROEXPAND-1 and start over.
;;; 3. Otherwise, assume it is a function call. "
(defun walk-form-internal (form context env)
;; First apply the walk-function to perform whatever translation
(not (fboundp fn))
(special-operator-p fn))
;; This shouldn't happen, since this walker is now
- ;; maintained as part of SBCL, so it should know about all
- ;; the special forms that SBCL knows about.
+ ;; maintained as part of SBCL, so it should know
+ ;; about all the special forms that SBCL knows
+ ;; about.
(error "unexpected special form ~S" fn))
(t
- ;; Otherwise, walk the form as if it's just a standard
- ;; function call using a template for standard function
- ;; call.
+ ;; Otherwise, walk the form as if it's just a
+ ;; standard function call using a template for
+ ;; standard function call.
(walk-template
newnewform '(call repeat (eval)) context env))))))))))))
(repeat
(walk-template-handle-repeat form
(cdr template)
- ;; For the case where nothing happens
- ;; after the repeat optimize out the
- ;; call to length.
+ ;; For the case where nothing
+ ;; happens after the repeat
+ ;; optimize away the call to
+ ;; LENGTH.
(if (null (cddr template))
()
(nthcdr (- (length form)
(relist-internal x args nil)))
(defun relist* (x &rest args)
- (relist-internal x args 't))
+ (relist-internal x args t))
(defun relist-internal (x args *p)
(if (null (cdr args))
form
(walk-declarations (cdr body) fn env t)))
((and (listp form) (eq (car form) 'declare))
- ;; We got ourselves a real live declaration. Record it, look for more.
+ ;; We got ourselves a real live declaration. Record it, look
+ ;; for more.
(dolist (declaration (cdr form))
(let ((type (car declaration))
(name (cadr declaration))
(args (cddr declaration)))
- (if (member type *variable-declarations*)
+ (if (member type *var-declarations*)
(note-declaration `(,type
- ,(or (variable-lexical-p name env) name)
+ ,(or (var-lexical-p name env) name)
,.args)
env)
(note-declaration declaration env))
(not (symbolp (caddr arg)))
(note-lexical-binding (caddr arg) env))))
(t
- (error "Can't understand something in the arglist ~S" arglist))))
+ (error "can't understand something in the arglist ~S" arglist))))
(defun walk-let (form context env)
(walk-let/let* form context env nil))
(defun walk-let* (form context env)
(walk-let/let* form context env t))
-(defun walk-prog (form context env)
- (walk-prog/prog* form context env nil))
-
-(defun walk-prog* (form context env)
- (walk-prog/prog* form context env t))
-
-(defun walk-do (form context env)
- (walk-do/do* form context env nil))
-
-(defun walk-do* (form context env)
- (walk-do/do* form context env t))
-
(defun walk-let/let* (form context old-env sequentialp)
(walker-environment-bind (new-env old-env)
(let* ((let/let* (car form))
(relist*
form locally walked-body)))
-(defun walk-prog/prog* (form context old-env sequentialp)
- (walker-environment-bind (new-env old-env)
- (let* ((possible-block-name (second form))
- (blocked-prog (and (symbolp possible-block-name)
- (not (eq possible-block-name 'nil)))))
- (multiple-value-bind (let/let* block-name bindings body)
- (if blocked-prog
- (values (car form) (cadr form) (caddr form) (cdddr form))
- (values (car form) nil (cadr form) (cddr form)))
- (let* ((walked-bindings
- (walk-bindings-1 bindings
- old-env
- new-env
- context
- sequentialp))
- (walked-body
- (walk-declarations
- body
- #'(lambda (real-body real-env)
- (walk-tagbody-1 real-body context real-env))
- new-env)))
- (if block-name
- (relist*
- form let/let* block-name walked-bindings walked-body)
- (relist*
- form let/let* walked-bindings walked-body)))))))
-
-(defun walk-do/do* (form context old-env sequentialp)
- (walker-environment-bind (new-env old-env)
- (let* ((do/do* (car form))
- (bindings (cadr form))
- (end-test (caddr form))
- (body (cdddr form))
- (walked-bindings (walk-bindings-1 bindings
- old-env
- new-env
- context
- sequentialp))
- (walked-body
- (walk-declarations body #'walk-repeat-eval new-env)))
- (relist* form
- do/do*
- (walk-bindings-2 bindings walked-bindings context new-env)
- (walk-template end-test '(test repeat (eval)) context new-env)
- walked-body))))
-
(defun walk-let-if (form context env)
(let ((test (cadr form))
(bindings (caddr form))
(body (cdddr form)))
(walk-form-internal
`(let ()
- (declare (special ,@(mapcar #'(lambda (x) (if (listp x) (car x) x))
+ (declare (special ,@(mapcar (lambda (x) (if (listp x) (car x) x))
bindings)))
(flet ((.let-if-dummy. () ,@body))
(if ,test
(defun walk-multiple-value-setq (form context env)
(let ((vars (cadr form)))
- (if (some #'(lambda (var)
- (variable-symbol-macro-p var env))
+ (if (some (lambda (var)
+ (variable-symbol-macro-p var env))
vars)
- (let* ((temps (mapcar #'(lambda (var)
- (declare (ignore var))
- (gensym))
+ (let* ((temps (mapcar (lambda (var)
+ (declare (ignore var))
+ (gensym))
vars))
- (sets (mapcar #'(lambda (var temp) `(setq ,var ,temp))
+ (sets (mapcar (lambda (var temp) `(setq ,var ,temp))
vars
temps))
(expanded `(multiple-value-bind ,temps ,(caddr form)
(walked-body
(walk-declarations
body
- #'(lambda (real-body real-env)
- (setq walked-bindings
- (walk-bindings-1 bindings
- old-env
- new-env
- context
- nil))
- (walk-repeat-eval real-body real-env))
+ (lambda (real-body real-env)
+ (setq walked-bindings
+ (walk-bindings-1 bindings
+ old-env
+ new-env
+ context
+ nil))
+ (walk-repeat-eval real-body real-env))
new-env)))
(relist* form mvb walked-bindings mv-form walked-body))))
(if sequentialp
new-env
old-env))
- (cddr binding)) ; Save cddr for DO/DO*;
- ; it is the next value
- ; form. Don't walk it
- ; now though.
+ ;; Save cddr for DO/DO*; it is
+ ;; the next value form. Don't
+ ;; walk it now, though.
+ (cddr binding))
(note-lexical-binding (car binding) new-env)))
(walk-bindings-1 (cdr bindings)
old-env
(walker-environment-bind
(new-env old-env
:lexical-variables
- (append (mapcar #'(lambda (binding)
- `(,(car binding)
- :macro . ,(cadr binding)))
+ (append (mapcar (lambda (binding)
+ `(,(car binding)
+ :macro . ,(cadr binding)))
bindings)
(env-lexical-variables old-env)))
(relist* form 'symbol-macrolet bindings
new-env))))))
(defun walk-if (form context env)
- (let ((predicate (cadr form))
- (arm1 (caddr form))
- (arm2
- (if (cddddr form)
- ;; FIXME: This should go away now that we're no longer trying
- ;; to support any old weird CLTL1.
- (progn
- (warn "In the form:~%~S~%~
- IF only accepts three arguments, you are using ~D.~%~
- It is true that some Common Lisps support this, but ~
- it is not~%~
- truly legal Common Lisp. For now, this code ~
- walker is interpreting ~%~
- the extra arguments as extra else clauses. ~
- Even if this is what~%~
- you intended, you should fix your source code."
- form
- (length (cdr form)))
- (cons 'progn (cdddr form)))
- (cadddr form))))
+ (destructuring-bind (if predicate arm1 &optional arm2) form
+ (declare (ignore if)) ; should be 'IF
(relist form
'if
(walk-form-internal predicate context env)
(walk-form-internal arm1 context env)
(walk-form-internal arm2 context env))))
\f
-;;;; tests tests tests
+;;;; examples
#|
-;;; Here are some examples of the kinds of things you should be able to do
-;;; with your implementation of the macroexpansion environment hacking
-;;; mechanism.
+;;; Here are some examples of the kinds of things you should be able
+;;; to do with your implementation of the macroexpansion environment
+;;; hacking mechanism.
;;;
-;;; WITH-LEXICAL-MACROS is kind of like MACROLET, but it only takes names
-;;; of the macros and actual macroexpansion functions to use to macroexpand
-;;; them. The win about that is that for macros which want to wrap several
-;;; MACROLETs around their body, they can do this but have the macroexpansion
-;;; functions be compiled. See the WITH-RPUSH example.
+;;; WITH-LEXICAL-MACROS is kind of like MACROLET, but it only takes
+;;; names of the macros and actual macroexpansion functions to use to
+;;; macroexpand them. The win about that is that for macros which want
+;;; to wrap several MACROLETs around their body, they can do this but
+;;; have the macroexpansion functions be compiled. See the WITH-RPUSH
+;;; example.
;;;
-;;; If the implementation had a special way of communicating the augmented
-;;; environment back to the evaluator that would be totally great. It would
-;;; mean that we could just augment the environment then pass control back
-;;; to the implementations own compiler or interpreter. We wouldn't have
-;;; to call the actual walker. That would make this much faster. Since the
-;;; principal client of this is defmethod it would make compiling defmethods
-;;; faster and that would certainly be a win.
+;;; If the implementation had a special way of communicating the
+;;; augmented environment back to the evaluator that would be totally
+;;; great. It would mean that we could just augment the environment
+;;; then pass control back to the implementations own compiler or
+;;; interpreter. We wouldn't have to call the actual walker. That
+;;; would make this much faster. Since the principal client of this is
+;;; defmethod it would make compiling defmethods faster and that would
+;;; certainly be a win.
(defmacro with-lexical-macros (macros &body body &environment old-env)
(with-augmented-environment (new-env old-env :macros macros)
(walk-form (cons 'progn body) :environment new-env)))
(defun expand-rpush (form env)
+ (declare (ignore env))
`(push ,(caddr form) ,(cadr form)))
(defmacro with-rpush (&body body)
`(with-lexical-macros ,(list (list 'rpush #'expand-rpush)) ,@body))
-
-;;; Unfortunately, I don't have an automatic tester for the walker.
-;;; Instead there is this set of test cases with a description of
-;;; how each one should go.
-(defmacro take-it-out-for-a-test-walk (form)
- `(take-it-out-for-a-test-walk-1 ',form))
-
-(defun take-it-out-for-a-test-walk-1 (form)
- (terpri)
- (terpri)
- (let ((copy-of-form (copy-tree form))
- (result (walk-form form nil
- #'(lambda (x y env)
- (format t "~&Form: ~S ~3T Context: ~A" x y)
- (when (symbolp x)
- (let ((lexical (variable-lexical-p x env))
- (special (variable-special-p x env)))
- (when lexical
- (format t ";~3T")
- (format t "lexically bound"))
- (when special
- (format t ";~3T")
- (format t "declared special"))
- (when (boundp x)
- (format t ";~3T")
- (format t "bound: ~S " (eval x)))))
- x))))
- (cond ((not (equal result copy-of-form))
- (format t "~%Warning: Result not EQUAL to copy of start."))
- ((not (eq result form))
- (format t "~%Warning: Result not EQ to copy of start.")))
- (pprint result)
- result))
-
-(defmacro foo (&rest ignore) ''global-foo)
-
-(defmacro bar (&rest ignore) ''global-bar)
-
-(take-it-out-for-a-test-walk (list arg1 arg2 arg3))
-(take-it-out-for-a-test-walk (list (cons 1 2) (list 3 4 5)))
-
-(take-it-out-for-a-test-walk (progn (foo) (bar 1)))
-
-(take-it-out-for-a-test-walk (block block-name a b c))
-(take-it-out-for-a-test-walk (block block-name (list a) b c))
-
-(take-it-out-for-a-test-walk (catch catch-tag (list a) b c))
-;;; This is a fairly simple macrolet case. While walking the body of the
-;;; macro, x should be lexically bound. In the body of the macrolet form
-;;; itself, x should not be bound.
-(take-it-out-for-a-test-walk
- (macrolet ((foo (x) (list x) ''inner))
- x
- (foo 1)))
-
-;;; A slightly more complex macrolet case. In the body of the macro x
-;;; should not be lexically bound. In the body of the macrolet form itself
-;;; x should be bound. Note that THIS CASE WILL CAUSE AN ERROR when it
-;;; tries to macroexpand the call to foo.
-(take-it-out-for-a-test-walk
- (let ((x 1))
- (macrolet ((foo () (list x) ''inner))
- x
- (foo))))
-
-(take-it-out-for-a-test-walk
- (flet ((foo (x) (list x y))
- (bar (x) (list x y)))
- (foo 1)))
-
-(take-it-out-for-a-test-walk
- (let ((y 2))
- (flet ((foo (x) (list x y))
- (bar (x) (list x y)))
- (foo 1))))
-
-(take-it-out-for-a-test-walk
- (labels ((foo (x) (bar x))
- (bar (x) (foo x)))
- (foo 1)))
-
-(take-it-out-for-a-test-walk
- (flet ((foo (x) (foo x)))
- (foo 1)))
-
-(take-it-out-for-a-test-walk
- (flet ((foo (x) (foo x)))
- (flet ((bar (x) (foo x)))
- (bar 1))))
-
-(take-it-out-for-a-test-walk (prog () (declare (special a b))))
-(take-it-out-for-a-test-walk (let (a b c)
- (declare (special a b))
- (foo a) b c))
-(take-it-out-for-a-test-walk (let (a b c)
- (declare (special a) (special b))
- (foo a) b c))
-(take-it-out-for-a-test-walk (let (a b c)
- (declare (special a))
- (declare (special b))
- (foo a) b c))
-(take-it-out-for-a-test-walk (let (a b c)
- (declare (special a))
- (declare (special b))
- (let ((a 1))
- (foo a) b c)))
-(take-it-out-for-a-test-walk (eval-when ()
- a
- (foo a)))
-(take-it-out-for-a-test-walk (eval-when (eval when load)
- a
- (foo a)))
-
-(take-it-out-for-a-test-walk (multiple-value-bind (a b) (foo a b) (list a b)))
-(take-it-out-for-a-test-walk (multiple-value-bind (a b)
- (foo a b)
- (declare (special a))
- (list a b)))
-(take-it-out-for-a-test-walk (progn (function foo)))
-(take-it-out-for-a-test-walk (progn a b (go a)))
-(take-it-out-for-a-test-walk (if a b c))
-(take-it-out-for-a-test-walk (if a b))
-(take-it-out-for-a-test-walk ((lambda (a b) (list a b)) 1 2))
-(take-it-out-for-a-test-walk ((lambda (a b) (declare (special a)) (list a b))
- 1 2))
-(take-it-out-for-a-test-walk (let ((a a) (b a) (c b)) (list a b c)))
-(take-it-out-for-a-test-walk (let* ((a a) (b a) (c b)) (list a b c)))
-(take-it-out-for-a-test-walk (let ((a a) (b a) (c b))
- (declare (special a b))
- (list a b c)))
-(take-it-out-for-a-test-walk (let* ((a a) (b a) (c b))
- (declare (special a b))
- (list a b c)))
-(take-it-out-for-a-test-walk (let ((a 1) (b 2))
- (foo bar)
- (declare (special a))
- (foo a b)))
-(take-it-out-for-a-test-walk (multiple-value-call #'foo a b c))
-(take-it-out-for-a-test-walk (multiple-value-prog1 a b c))
-(take-it-out-for-a-test-walk (progn a b c))
-(take-it-out-for-a-test-walk (progv vars vals a b c))
-(take-it-out-for-a-test-walk (quote a))
-(take-it-out-for-a-test-walk (return-from block-name a b c))
-(take-it-out-for-a-test-walk (setq a 1))
-(take-it-out-for-a-test-walk (setq a (foo 1) b (bar 2) c 3))
-(take-it-out-for-a-test-walk (tagbody a b c (go a)))
-(take-it-out-for-a-test-walk (the foo (foo-form a b c)))
-(take-it-out-for-a-test-walk (throw tag-form a))
-(take-it-out-for-a-test-walk (unwind-protect (foo a b) d e f))
-
-(defmacro flet-1 (a b) ''outer)
-(defmacro labels-1 (a b) ''outer)
-
-(take-it-out-for-a-test-walk
- (flet ((flet-1 (a b) () (flet-1 a b) (list a b)))
- (flet-1 1 2)
- (foo 1 2)))
-(take-it-out-for-a-test-walk
- (labels ((label-1 (a b) () (label-1 a b)(list a b)))
- (label-1 1 2)
- (foo 1 2)))
-(take-it-out-for-a-test-walk (macrolet ((macrolet-1 (a b) (list a b)))
- (macrolet-1 a b)
- (foo 1 2)))
-
-(take-it-out-for-a-test-walk (macrolet ((foo (a) `(inner-foo-expanded ,a)))
- (foo 1)))
-
-(take-it-out-for-a-test-walk (progn (bar 1)
- (macrolet ((bar (a)
- `(inner-bar-expanded ,a)))
- (bar 2))))
-
-(take-it-out-for-a-test-walk (progn (bar 1)
- (macrolet ((bar (s)
- (bar s)
- `(inner-bar-expanded ,s)))
- (bar 2))))
-
-(take-it-out-for-a-test-walk (cond (a b)
- ((foo bar) a (foo a))))
-
-(let ((the-lexical-variables ()))
- (walk-form '(let ((a 1) (b 2))
- #'(lambda (x) (list a b x y)))
- ()
- #'(lambda (form context env)
- (when (and (symbolp form)
- (variable-lexical-p form env))
- (push form the-lexical-variables))
- form))
- (or (and (= (length the-lexical-variables) 3)
- (member 'a the-lexical-variables)
- (member 'b the-lexical-variables)
- (member 'x the-lexical-variables))
- (error "Walker didn't do lexical variables of a closure properly.")))
-|#
+|#
\ No newline at end of file
projects / sbcl.git / blobdiff