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XCL-LOOP
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XCL-LOOP
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(DEFINE-FILE-INFO PACKAGE (DEFPACKAGE "LOOP" ( USE "LISP" "XCL")) READTABLE "XCL" BASE 10)
(il:filecreated " 8-Apr-2024 19:38:27" il:|{DSK}<home>larry>il>medley>sources>XCL-LOOP.;13| 61862
:edit-by "lmm"
:changes-to (il:vars il:xcl-loopcoms)
(il:functions cl::symbol-macrolet with-list-accumulator)
:previous-date " 2-Apr-2024 15:08:27" il:|{DSK}<home>larry>il>medley>sources>XCL-LOOP.;12|)
(il:prettycomprint il:xcl-loopcoms)
(il:rpaqq il:xcl-loopcoms
((file-environments il:loop)
(il:structures simple-program-error)
(il:variables *accumulators* *anonymous-accumulator* *boolean-terminator* *current-clause*
*current-keyword* *environment* *for-as-components* *for-as-subclauses*
*hash-group* *for-as-prepositions* *ignorable* *it-symbol* *it-visible-p*
*list-end-test* *loop-clauses* *loop-components* *loop-name* *loop-tokens*
*message-prefix* *symbol-group* *temporaries*)
(il:functions %keyword %list accumulate-in-list accumulation-clause accumulator-kind
accumulator-spec along-with always-never-thereis-clause ambiguous-loop-result-error
append-context appendf bindings bound-variables by-step-fun car-type cdr-type
check-multiple-bindings cl-external-p clause* clause1 compound-forms*
compound-forms+ conditional-clause constant-bindings constant-function-p
constant-vector constant-vector-p d-var-spec-p d-var-spec1 d-var-type-spec
declarations default-binding default-bindings default-type default-value
destructuring-multiple-value-bind destructuring-multiple-value-setq
dispatch-for-as-subclause do-clause empty-p enumerate extended-loop fill-in
finally-clause for for-as-across-subclause for-as-arithmetic-possible-prepositions
for-as-arithmetic-step-and-test-functions for-as-arithmetic-subclause
for-as-being-subclause for-as-clause for-as-equals-then-subclause for-as-fill-in
for-as-hash-subclause for-as-in-list-subclause for-as-on-list-subclause
for-as-package-subclause for-as-parallel-p form-or-it form1 gensym-ignorable
globally-special-p hash-d-var-spec initially-clause
invalid-accumulator-combination-error keyword1 keyword? let-form loop-error
loop-finish-test-forms loop-warn lp main-clause* mapappend
multiple-value-list-argument-form multiple-value-list-form-p name-clause? one
ordinary-bindings preposition1 preposition? psetq-forms quoted-form-p quoted-object
reduce-redundant-code repeat-clause return-clause selectable-clause simple-loop
simple-var-p simple-var1 stray-of-type-error cl::symbol-macrolet type-spec?
until-clause using-other-var variable-clause* while-clause with with-accumulators
with-binding-forms with-clause with-iterator-forms with-list-accumulator
with-loop-context with-numeric-accumulator with-temporaries zero)
(il:functions loop)
(il:prop (il:filetype il:makefile-environment il:copyright il:license)
il:xcl-loop)))
(define-file-environment il:loop :package (defpackage "LOOP" (:use "LISP" "XCL"))
:readtable "XCL")
(define-condition simple-program-error (simple-condition program-error)
nil)
(defvar *accumulators* nil)
(defvar *anonymous-accumulator* nil)
(defvar *boolean-terminator* nil)
(defvar *current-clause* nil)
(defvar *current-keyword* nil)
(defvar *environment*)
(defvar *for-as-components*)
(defvar *for-as-subclauses*
(let ((table (make-hash-table)))
(mapc #'(lambda (spec)
(destructuring-bind (subclause-name . keywords)
spec
(dolist (key keywords)
(setf (gethash key table)
subclause-name))))
'((for-as-arithmetic-subclause :from :downfrom :upfrom :to :downto :upto :below :above
:by)
(for-as-in-list-subclause :in)
(for-as-on-list-subclause :on)
(for-as-equals-then-subclause :=)
(for-as-across-subclause :across)
(for-as-being-subclause :being)))
table)
"A table mapping for-as prepositions to their processor function-designator.")
(defvar *hash-group* '(:hash-key :hash-keys :hash-value :hash-values))
(defvar *for-as-prepositions*
(let ((prepositions nil))
(maphash #'(lambda (key value)
(declare (ignore value))
(push key prepositions))
*for-as-subclauses*)
prepositions))
(defvar *ignorable* nil
"Ignorable temporary variables in *temporaries*.")
(defvar *it-symbol* nil)
(defvar *it-visible-p* nil)
(defvar *list-end-test* 'atom)
(defvar *loop-clauses*
(let ((table (make-hash-table)))
(mapc #'(lambda (spec)
(destructuring-bind (clause-name . keywords)
spec
(dolist (key keywords)
(setf (gethash key table)
clause-name))))
'((for-as-clause :for :as)
(with-clause :with)
(do-clause :do :doing)
(return-clause :return)
(initially-clause :initially)
(finally-clause :finally)
(accumulation-clause :collect :collecting :append :appending :nconc :nconcing :count
:counting :sum :summing :maximize :maximizing :minimize :minimizing)
(conditional-clause :if :when :unless)
(repeat-clause :repeat)
(always-never-thereis-clause :always :never :thereis)
(while-clause :while)
(until-clause :until)))
table)
"A table mapping loop keywords to their processor function-designator.")
(defvar *loop-components* nil)
(defvar *loop-name* nil)
(defvar *loop-tokens*)
(defvar *message-prefix* "")
(defvar *symbol-group* '(:symbol :symbols :present-symbol :present-symbols :external-symbol
:external-symbols))
(defvar *temporaries* nil
"Temporary variables used in with-clauses and for-as-clauses.")
(defun %keyword (designator)
(intern (string designator)
"KEYWORD"))
(defun %list (designator) (il:* il:\; "Edited 14-Mar-2024 11:46 by lmm")
(if (listp designator)
designator
(list designator)))
(defun accumulate-in-list (form accumulator-spec)
(destructuring-bind (name &key var splice &allow-other-keys)
accumulator-spec
(declare (ignore name))
(let* ((copy-f (ecase *current-keyword*
((:collect :collecting) 'list)
((:append :appending) 'copy-list)
((:nconc :nconcing) 'identity)))
(collecting-p (member *current-keyword* '(:collect :collecting)))
(last-f (if collecting-p
'cdr
'last))
(splicing-form (if collecting-p
`(rplacd ,splice (setq ,splice (list ,form)))
`(setf (cdr ,splice)
(,copy-f ,form)
,splice
(,last-f ,splice)))))
(if (globally-special-p var)
(lp :do `(if ,splice
,splicing-form
(setq ,splice (,last-f (setq ,var (,copy-f ,form))))))
(lp :do splicing-form)))))
(defun accumulation-clause ()
(let* ((form (form-or-it))
(name (if (preposition? :into)
(simple-var1)
(progn (setq *anonymous-accumulator* *current-keyword*)
(when *boolean-terminator* (ambiguous-loop-result-error))
nil)))
(accumulator-spec (accumulator-spec name)))
(destructuring-bind (name &rest plist &key var &allow-other-keys)
accumulator-spec
(declare (ignore name))
(ecase *current-keyword*
((:collect :collecting :append :appending :nconc :nconcing) (accumulate-in-list
form
accumulator-spec))
((:count :counting) (lp :if form :do `(incf ,var)))
((:sum :summing) (lp :do `(incf ,var ,form)))
((:maximize :maximizing :minimize :minimizing)
(let ((first-p (getf plist :first-p))
(fun (if (member *current-keyword* '(:maximize :maximizing))
'<
'>)))
(lp :do `(let ((value ,form))
(cond
(,first-p (setq ,first-p nil ,var value))
((,fun ,var value)
(setq ,var value)))))))))))
(defun accumulator-kind (key)
(ecase key
((:collect :collecting :append :appending :nconc :nconcing) :list)
((:sum :summing :count :counting) :total)
((:maximize :maximizing :minimize :minimizing) :limit)))
(defun accumulator-spec (name)
(let* ((kind (accumulator-kind *current-keyword*))
(spec (assoc name *accumulators*))
(plist (cdr spec)))
(if spec
(if (not (eq kind (getf plist :kind)))
(invalid-accumulator-combination-error (reverse (getf plist :keys)))
(progn (pushnew *current-keyword* (getf plist :keys))
(when (member kind '(:total :limit))
(multiple-value-bind (type supplied-p)
(type-spec?)
(when supplied-p
(push type (getf plist :types)))))))
(let ((var (or name (gensym "ACCUMULATOR-"))))
(setq plist `(:var ,var :kind ,kind :keys (,*current-keyword*)))
(ecase kind
(:list
(setf (getf plist :splice)
(gensym "SPLICE-"))
(unless name
(fill-in :results `((cdr ,var)))))
((:total :limit)
(multiple-value-bind (type supplied-p)
(type-spec?)
(when supplied-p
(push type (getf plist :types))))
(when (eq kind :limit)
(let ((first-p (gensym "FIRST-P-")))
(setf (getf plist :first-p)
first-p)
(with first-p t := t)))
(unless name
(fill-in :results `(,var)))))
(push (setq spec `(,name ,@plist))
*accumulators*)))
spec))
(defun along-with (var type &key equals (then equals))
(for-as-fill-in :bindings (apply #'bindings type var (when (quoted-form-p equals)
`(,equals))))
(unless (quoted-form-p equals)
(for-as-fill-in :after-head `((setq ,@(mapappend #'cdr (bindings type var equals))))))
(for-as-fill-in :after-tail `((setq ,@(mapappend #'cdr (bindings type var then))))))
(defun always-never-thereis-clause ()
(setq *boolean-terminator* *current-keyword*)
(when *anonymous-accumulator* (ambiguous-loop-result-error))
(ecase *current-keyword*
(:always
(lp :unless (form1)
:return nil :end)
(fill-in :results '(t)))
(:never (lp :always `(not ,(form1))))
(:thereis
(lp :if (form1)
:return :it :end)
(fill-in :results '(nil)))))
(defun ambiguous-loop-result-error ()
(error 'simple-program-error :format-control (append-context
"~S cannot be used without `into' preposition with ~S"
)
:format-arguments
`(,*anonymous-accumulator* ,*boolean-terminator*)))
(defun append-context (message)
(concatenate 'string message (let ((clause (ldiff *current-clause* *loop-tokens*)))
(format nil "~%Current LOOP context:~{ ~S~}" clause))))
(define-modify-macro appendf (&rest args) append
"Append onto list")
(defun bindings (d-type-spec d-var-spec &optional (value-form "NEVER USED" value-form-p))
(cond
((null value-form-p)
(default-bindings d-type-spec d-var-spec))
((quoted-form-p value-form)
(constant-bindings d-type-spec d-var-spec (quoted-object value-form)))
(t (ordinary-bindings d-type-spec d-var-spec value-form))))
(defun bound-variables (binding-form)
(let ((operator (first binding-form))
(second (second binding-form)))
(ecase operator
((let let* symbol-macrolet) (mapcar #'first second))
((multiple-value-bind) second)
((with-package-iterator with-hash-table-iterator) `(,(first second))))))
(defun by-step-fun ()
(if (preposition? :by)
(form1)
'#'cdr))
(defun car-type (d-type-spec)
(if (consp d-type-spec)
(car d-type-spec)
d-type-spec))
(defun cdr-type (d-type-spec)
(if (consp d-type-spec)
(cdr d-type-spec)
d-type-spec))
(defun check-multiple-bindings (variables)
(mapl #'(lambda (vars)
(when (member (first vars)
(rest vars))
(loop-error 'simple-program-error :format-control
"Variable ~S is bound more than once." :format-arguments
(list (first vars)))))
variables))
(defun cl-external-p (symbol)
(multiple-value-bind (cl-symbol status)
(find-symbol (symbol-name symbol)
"CL")
(and (eq symbol cl-symbol)
(eq status :external))))
(defun clause* ()
(loop (let ((key (keyword?)))
(unless key (return))
(clause1))))
(defun clause1 ()
(multiple-value-bind (clause-function-designator present-p)
(gethash *current-keyword* *loop-clauses*)
(unless present-p
(loop-error "Unknown loop keyword ~S encountered." (car *current-clause*)))
(let ((*message-prefix* (format nil "LOOP ~A clause: " *current-keyword*)))
(funcall clause-function-designator))))
(defun compound-forms* ()
(when (and *loop-tokens* (consp (car *loop-tokens*)))
(cons (pop *loop-tokens*)
(compound-forms*))))
(defun compound-forms+ ()
(or (compound-forms*)
(loop-error "At least one compound form is needed.")))
(defun conditional-clause ()
(let* ((*it-symbol* nil)
(middle (gensym "MIDDLE-"))
(bottom (gensym "BOTTOM-"))
(test-form (if (eq *current-keyword* :unless)
`(not ,(form1))
(form1)))
(condition-form `(unless ,test-form
(go ,middle))))
(lp :do condition-form)
(let ((*it-visible-p* t))
(selectable-clause))
(loop (unless (preposition? :and)
(return))
(selectable-clause))
(cond
((preposition? :else)
(lp :do `(go ,bottom))
(fill-in :body `(,middle))
(let ((*it-visible-p* t))
(selectable-clause))
(loop (unless (preposition? :and)
(return))
(selectable-clause))
(fill-in :body `(,bottom)))
(t (fill-in :body `(,middle))))
(preposition? :end)
(when *it-symbol*
(with *it-symbol*)
(setf (second condition-form)
`(setq ,*it-symbol* ,(second condition-form))))))
(defun constant-bindings (d-type-spec d-var-spec value)
(let ((bindings nil))
(labels ((dig (type var value)
(cond
((null var)
nil)
((simple-var-p var)
(appendf bindings `((,type ,var ',value))))
(t (dig (car-type type)
(car var)
(car value))
(dig (cdr-type type)
(cdr var)
(cdr value))))))
(dig d-type-spec d-var-spec value)
bindings)))
(defun constant-function-p (form)
(let ((expansion (macroexpand form *environment*)))
(and (consp expansion)
(eq (first expansion)
'function)
(symbolp (second expansion))
(let ((symbol (second expansion)))
(and (cl-external-p symbol)
(fboundp symbol))))))
(defun constant-vector (form)
(cond
((quoted-form-p form)
(quoted-object form))
((vectorp form)
form)
(t (error "~S is not a vector form." form))))
(defun constant-vector-p (form)
(or (quoted-form-p form)
(vectorp form)))
(defun d-var-spec-p (spec)
(or (simple-var-p spec)
(null spec)
(and (consp spec)
(d-var-spec-p (car spec))
(d-var-spec-p (cdr spec)))))
(defun d-var-spec1 ()
(unless (and *loop-tokens* (d-var-spec-p (car *loop-tokens*)))
(loop-error "A destructured-variable-spec is missing."))
(let ((d-var-spec (pop *loop-tokens*)))
d-var-spec))
(defun d-var-type-spec ()
(let ((var (d-var-spec1))
(type (type-spec?)))
(when (empty-p var)
(unless (member type '(nil t))
(loop-warn "Type spec ~S is ignored." type))
(setq var (gensym)
type t))
(values var type)))
(defun declarations (bindings)
(let ((declarations (mapcan #'(lambda (binding)
(destructuring-bind (type var . rest)
binding
(declare (ignore rest))
(unless (eq type 't)
`((type ,type ,var)))))
bindings)))
(when declarations
`((declare ,@declarations)))))
(defun default-binding (type var)
`(,(default-type type)
,var
,(default-value type)))
(defun default-bindings (d-type-spec d-var-spec)
(let ((bindings nil))
(labels ((dig (type var)
(cond
((null var)
nil)
((simple-var-p var)
(appendf bindings `(,(default-binding type var))))
(t (dig (car-type type)
(car var))
(dig (cdr-type type)
(cdr var))))))
(dig d-type-spec d-var-spec)
bindings)))
(defun default-type (type)
(if (eq type t)
t
(let ((value (default-value type)))
(if (typep value type)
type
(let ((default-type (type-of value)))
(if (subtypep type default-type)
default-type
(if (null value)
`(or null ,type)
`(or ,default-type ,type))))))))
(defun default-value (type)
(cond
((subtypep type 'bignum)
(1+ most-positive-fixnum))
((subtypep type 'integer)
0)
((subtypep type 'ratio)
1/10)
((subtypep type 'float)
0.0)
((subtypep type 'number)
0)
((subtypep type 'character)
#\Space)
((subtypep type 'string)
"")
((subtypep type 'bit-vector)
#*0)
((subtypep type 'vector)
#())
((subtypep type 'package)
*package*)
(t nil)))
(defun destructuring-multiple-value-bind (d-type-spec d-var-spec value-form)
(let ((mv-bindings nil)
(d-bindings nil)
(padding-temps nil)
temp)
(do ((vars d-var-spec (cdr vars))
(types d-type-spec (cdr-type types)))
((endp vars))
(if (listp (car vars))
(progn (setq temp (gensym))
(appendf mv-bindings `((t ,temp)))
(appendf d-bindings `((,(car-type types)
,(car vars)
,temp)))
(when (empty-p (car vars))
(push temp padding-temps)))
(appendf mv-bindings `((,(car-type types)
,(car vars))))))
(fill-in :binding-forms
`((multiple-value-bind ,(mapcar #'second mv-bindings)
,(multiple-value-list-argument-form value-form)
,@(declarations mv-bindings)
,@(when padding-temps
`((declare (ignore ,@padding-temps)))))))
(let ((bindings (mapappend #'(lambda (d-binding)
(apply #'bindings d-binding))
d-bindings)))
(when bindings
(fill-in :binding-forms `(,(let-form bindings)))))))
(defun destructuring-multiple-value-setq (d-var-spec value-form &key iterator-p)
(let (d-bindings mv-vars temp)
(do ((vars d-var-spec (cdr vars)))
((endp vars))
(if (listp (car vars))
(progn (setq temp (or (pop *temporaries*)
(gensym-ignorable)))
(appendf mv-vars `(,temp))
(appendf d-bindings `((t ,(car vars)
,temp))))
(appendf mv-vars `(,(car vars)))))
(let ((mv-setq-form `(multiple-value-setq ,mv-vars ,value-form))
(bindings nil))
(do ((d-bindings d-bindings (cdr d-bindings)))
((endp d-bindings))
(destructuring-bind (type var temp)
(car d-bindings)
(declare (ignore type var))
(push temp *temporaries*)
(appendf bindings (apply #'bindings (car d-bindings)))))
(when iterator-p
(setq mv-setq-form `(unless ,mv-setq-form (loop-finish))))
(if bindings
`(progn ,mv-setq-form (setq ,@(mapappend #'cdr bindings)))
mv-setq-form))))
(defun dispatch-for-as-subclause (var type)
(unless *loop-tokens* (loop-error "A preposition is missing."))
(let ((preposition (preposition1 *for-as-prepositions*)))
(multiple-value-bind (subclause-function-designator present-p)
(gethash preposition *for-as-subclauses*)
(unless present-p (loop-error "Unknown preposition ~S is supplied." preposition))
(push preposition *loop-tokens*)
(funcall subclause-function-designator var type))))
(defun do-clause ()
(fill-in :body (compound-forms+)))
(defun empty-p (d-var-spec)
(or (null d-var-spec)
(and (consp d-var-spec)
(empty-p (car d-var-spec))
(empty-p (cdr d-var-spec)))))
(defun enumerate (items)
(case (length items)
(1 (format nil "~S" (first items)))
(2 (format nil "~S and ~S" (first items)
(second items)))
(t (format nil "~{~S, ~}and ~S" (butlast items)
(first (last items))))))
(defmacro extended-loop (&rest tokens &environment environment)
(let
((*environment* environment))
(with-loop-context
tokens
(let
((body-tag (gensym "LOOP-BODY-"))
(epilogue-tag (gensym "LOOP-EPILOGUE-")))
(name-clause?)
(variable-clause*)
(main-clause*)
(when *loop-tokens* (error "Loop form tail ~S remained unprocessed." *loop-tokens*))
(reduce-redundant-code)
(destructuring-bind
(&key binding-forms iterator-forms initially head neck body tail finally results)
*loop-components*
(check-multiple-bindings (append *temporaries* (mapappend #'bound-variables binding-forms)
(mapcar #'(lambda (spec)
(getf (cdr spec)
:var))
*accumulators*)))
`(block ,*loop-name*
,(with-temporaries
`(,*temporaries* :ignorable ,*ignorable*)
(with-accumulators
*accumulators*
(with-binding-forms
binding-forms
(with-iterator-forms
iterator-forms
`(macrolet ((loop-finish nil '(go ,epilogue-tag)))
(tagbody ,@head ,@initially ,body-tag ,@neck ,@body ,@tail
(go ,body-tag)
,epilogue-tag
,@finally
,@(when results
`((return-from ,*loop-name* ,(car results))))))))))))))))
(defun fill-in (&rest args)
(when args
(appendf (getf *loop-components* (first args))
(second args))
(apply #'fill-in (cddr args))))
(defun finally-clause ()
(fill-in :finally (compound-forms+)))
(defun for (var type &rest rest)
(let ((*loop-tokens* rest))
(dispatch-for-as-subclause var type)))
(defun for-as-across-subclause (var type)
(preposition1 :across)
(let* ((form (form1))
(vector (if (constant-vector-p form)
form
(gensym "VECTOR-")))
(length (if (constant-vector-p form)
(length (constant-vector form))
(gensym "LENGTH-")))
(i (gensym "INDEX-"))
(at-least-one-iteration-p (and (constant-vector-p form)
(plusp length))))
(unless (constant-vector-p form)
(for-as-fill-in :bindings `((t ,vector ,form))
:bindings2
`((fixnum ,length (length ,vector)))))
(for-as-fill-in :bindings `((fixnum ,i 0))
:head-tests
(unless at-least-one-iteration-p
`((= ,i ,length)))
:tail-psetq
`(,i (1+ ,i))
:tail-tests
`((= ,i ,length)))
(along-with var type :equals (if at-least-one-iteration-p
`',(aref (constant-vector form)
0)
`(aref ,vector ,i))
:then
`(aref ,vector ,i))))
(defun for-as-arithmetic-possible-prepositions (used-prepositions)
(append (cond
((intersection '(:from :downfrom :upfrom)
used-prepositions)
nil)
((intersection '(:downto :above)
used-prepositions)
'(:from :downfrom))
((intersection '(:upto :below)
used-prepositions)
'(:from :upfrom))
(t '(:from :downfrom :upfrom)))
(cond
((intersection '(:to :downto :upto :below :above)
used-prepositions)
nil)
((find :upfrom used-prepositions)
'(:to :upto :below))
((find :downfrom used-prepositions)
'(:to :downto :above))
(t '(:to :downto :upto :below :above)))
(unless (find :by used-prepositions)
'(:by))))
(defun for-as-arithmetic-step-and-test-functions (used-prepositions)
(let ((up-p (subsetp used-prepositions '(:below :upto :upfrom :from :to :by))))
(values (if up-p
'+
'-)
(cond
((member :to used-prepositions)
(if up-p
'>
'<))
((member :upto used-prepositions)
'>)
((member :below used-prepositions)
'>=)
((member :downto used-prepositions)
'<)
((member :above used-prepositions)
'<=)
(t nil)))))
(defun for-as-arithmetic-subclause (var type)
(unless (simple-var-p var)
(loop-error "Destructuring on a number is invalid."))
(multiple-value-bind (subtype-p valid-p)
(subtypep type 'real)
(when (and (not subtype-p)
valid-p)
(setq type 'real)))
(let (from to by preposition used candidates bindings)
(loop (setq candidates (or (for-as-arithmetic-possible-prepositions used)
(return)))
(push (or (setq preposition (preposition? candidates))
(return))
used)
(let ((value-form (form1)))
(if (member preposition '(:from :downfrom :upfrom))
(progn (setq from value-form)
(appendf bindings `((,type ,var ,from))))
(progn (when (not (constantp value-form *environment*))
(let ((temp (gensym)))
(appendf bindings `((number ,temp ,value-form)))
(setq value-form temp)))
(ecase preposition
((:to :downto :upto :below :above) (setq to value-form))
(:by (setq by value-form)))))))
(unless (intersection used '(:from :downfrom :upfrom))
(appendf bindings `((,type ,var ,(zero type)))))
(multiple-value-bind (step test)
(for-as-arithmetic-step-and-test-functions used)
(let ((tests (when test
`((,test ,var ,to)))))
(for-as-fill-in :bindings bindings :head-tests tests :tail-psetq
`(,var (,step ,var ,(or by (one type))))
:tail-tests tests)))))
(defun for-as-being-subclause (var type)
(preposition1 :being)
(preposition1 '(:each :the))
(let* ((kind (preposition1 (append *hash-group* *symbol-group*))))
(cond
((find kind *hash-group*)
(for-as-hash-subclause var type kind))
((find kind *symbol-group*)
(for-as-package-subclause var type kind))
(t (loop-error "Internal logic error")))))
(defun for-as-clause ()
(let ((*for-as-components* nil))
(loop (multiple-value-bind (var type)
(d-var-type-spec)
(dispatch-for-as-subclause var type))
(unless (preposition? :and)
(return)))
(destructuring-bind (&key bindings bindings2 before-head head-psetq head-tests after-head
before-tail tail-psetq tail-tests after-tail)
*for-as-components*
(fill-in :binding-forms `(,@(when bindings
`(,(let-form bindings)))
,@(when bindings2
`(,(let-form bindings2))))
:head
`(,@before-head ,@(psetq-forms head-psetq)
,@(loop-finish-test-forms head-tests)
,@after-head)
:tail
`(,@before-tail ,@(psetq-forms tail-psetq)
,@(loop-finish-test-forms tail-tests)
,@after-tail)))))
(defun for-as-equals-then-subclause (var type)
(preposition1 :=)
(let* ((first (form1))
(then (if (preposition? :then)
(form1)
first))
(parallel-p (for-as-parallel-p)))
(for-as-fill-in :bindings (apply #'bindings type var (when (quoted-form-p first)
`(,first))))
(if (and (not parallel-p)
(consp var)
(multiple-value-list-form-p first))
(for-as-fill-in :before-head `(,(destructuring-multiple-value-setq var (
multiple-value-list-argument-form
first))))
(unless (quoted-form-p first)
(for-as-fill-in :head-psetq (mapappend #'cdr (bindings type var first)))))
(if (and (not parallel-p)
(consp var)
(multiple-value-list-form-p then))
(for-as-fill-in :before-tail `(,(destructuring-multiple-value-setq var (
multiple-value-list-argument-form
then))))
(for-as-fill-in :tail-psetq (mapappend #'cdr (bindings type var then))))))
(defun for-as-fill-in (&rest key-list-pairs)
(when key-list-pairs
(destructuring-bind (key list . rest)
key-list-pairs
(appendf (getf *for-as-components* key)
list)
(apply #'for-as-fill-in rest))))
(defun for-as-hash-subclause (var type kind)
(let* ((hash-table (progn (preposition1 '(:in :of))
(form1)))
(other-var (using-other-var kind))
(for-as-parallel-p (for-as-parallel-p))
(returned-p (or (pop *temporaries*)
(gensym-ignorable)))
(iterator (gensym))
narrow-typed-var narrow-type)
(when (and (simple-var-p var)
(not (typep 'nil type)))
(setq narrow-typed-var var narrow-type type)
(setq var (gensym)
type
`(or null ,type))
(for-as-fill-in :bindings `(,(default-binding narrow-type narrow-typed-var))))
(flet ((iterator-form nil `(with-hash-table-iterator (,iterator ,hash-table))))
(if for-as-parallel-p
(progn (unless (constantp hash-table *environment*)
(let ((temp (gensym "HASH-TABLE-")))
(for-as-fill-in :bindings `((t ,temp ,hash-table)))
(setq hash-table temp)))
(fill-in :iterator-forms `(,(iterator-form))))
(fill-in :binding-forms `(,(iterator-form)))))
(let* ((d-var-spec (hash-d-var-spec returned-p var other-var kind))
(d-mv-setq (destructuring-multiple-value-setq d-var-spec `(,iterator)
:iterator-p t))
(setters `(,d-mv-setq ,@(when narrow-typed-var
`((setq ,narrow-typed-var ,var))))))
(push returned-p *temporaries*)
(for-as-fill-in :bindings `(,@(bindings type var)
,@(when other-var (bindings t other-var)))
:after-head setters :after-tail setters))))
(defun for-as-in-list-subclause (var type)
(preposition1 :in)
(let ((*list-end-test* 'endp))
(for `(,var)
`(,type)
:on
(form1)
:by
(by-step-fun))))
(defun for-as-on-list-subclause (var type)
(preposition1 :on)
(let* ((form (form1))
(by-step-fun (by-step-fun))
(test *list-end-test*)
(list-var (if (simple-var-p var)
var
(gensym "LIST-")))
(list-type (if (simple-var-p var)
type
t))
(at-least-one-iteration-p (and (quoted-form-p form)
(not (funcall test (quoted-object form))))))
(for-as-fill-in :bindings `((,list-type ,list-var ,form)
,@(unless (constant-function-p by-step-fun)
(let ((temp (gensym "STEPPER-")))
(prog1 `((t ,temp ,by-step-fun))
(setq by-step-fun temp)))))
:head-tests
(unless at-least-one-iteration-p
`((,test ,list-var)))
:tail-psetq
`(,list-var (funcall ,by-step-fun ,list-var))
:tail-tests
`((,test ,list-var)))
(unless (simple-var-p var)
(along-with var type :equals (if at-least-one-iteration-p
form
list-var)
:then list-var))))
(defun for-as-package-subclause (var type kind)
(let* ((package (if (preposition? '(:in :of))
(form1)
'*package*))
(for-as-parallel-p (for-as-parallel-p))
(returned-p (or (pop *temporaries*)
(gensym-ignorable)))
(iterator (gensym))
(kinds (ecase kind
((:symbol :symbols) '(:internal :external :inherited))
((:present-symbol :present-symbols) '(:internal :external))
((:external-symbol :external-symbols) '(:external)))))
(unless (typep 'nil type)
(setq type `(or null ,type)))
(flet ((iterator-form nil `(with-package-iterator (,iterator ,package ,@kinds))))
(if for-as-parallel-p
(progn (unless (constantp package *environment*)
(let ((temp (gensym "PACKAGE-")))
(for-as-fill-in :bindings `((t ,temp ,package)))
(setq package temp)))
(fill-in :iterator-forms `(,(iterator-form))))
(fill-in :binding-forms `(,(iterator-form)))))
(let* ((d-var-spec `(,returned-p ,var))
(d-mv-setq (destructuring-multiple-value-setq d-var-spec `(,iterator)
:iterator-p t)))
(push returned-p *temporaries*)
(for-as-fill-in :bindings (bindings type var)
:after-head
`(,d-mv-setq)
:after-tail
`(,d-mv-setq)))))
(defun for-as-parallel-p ()
(or *for-as-components* (and *loop-tokens* (symbolp (car *loop-tokens*))
(string= (symbol-name (car *loop-tokens*))
"AND"))))
(defun form-or-it ()
(if (and *it-visible-p* (preposition? :it))
(or *it-symbol* (setq *it-symbol* (gensym)))
(form1)))
(defun form1 ()
(unless *loop-tokens* (loop-error "A normal lisp form is missing."))
(pop *loop-tokens*))
(defun gensym-ignorable ()
(let ((var (gensym)))
(push var *ignorable*)
var))
(defun globally-special-p (symbol)
(assert (symbolp symbol))
(il:variable-globally-special-p symbol))
(defun hash-d-var-spec (returned-p var other-var kind)
(if (find kind '(:hash-key :hash-keys))
`(,returned-p ,var ,other-var)
`(,returned-p ,other-var ,var)))
(defun initially-clause ()
(fill-in :initially (compound-forms+)))
(defun invalid-accumulator-combination-error (keys)
(loop-error "Accumulator ~S cannot be mixed with ~S." *current-keyword* (enumerate keys)))
(defun keyword1 (keyword-list-designator &key prepositionp)
(let ((keywords (%list keyword-list-designator)))
(or (keyword? keywords)
(let ((length (length keywords))
(kind (if prepositionp
"preposition"
"keyword")))
(case length
(0 (loop-error "A loop ~A is missing." kind))
(1 (loop-error "Loop ~A ~S is missing." kind (car keywords)))
(t (loop-error "One of the loop ~As ~S must be supplied." kind keywords)))))))
(defun keyword? (&optional keyword-list-designator)
(and *loop-tokens* (symbolp (car *loop-tokens*))
(let ((keyword-list (%list keyword-list-designator))
(keyword (%keyword (car *loop-tokens*))))
(and (or (null keyword-list)
(find keyword keyword-list))
(setq *current-clause* *loop-tokens* *loop-tokens* (rest *loop-tokens*)
*current-keyword* keyword)))))
(defun let-form (bindings)
`(let ,(mapcar #'cdr bindings)
,@(declarations bindings)))
(defun loop-error (datum &rest arguments)
(when (stringp datum)
(setq datum (append-context datum)))
(apply #'error datum arguments))
(defun loop-finish-test-forms (tests)
(case (length tests)
(0 nil)
(1 `((when ,@tests (loop-finish))))