1 ;;;; the LOOP iteration macro
3 ;;;; This software is part of the SBCL system. See the README file for
6 ;;;; This code was modified by William Harold Newman beginning
7 ;;;; 19981106, originally to conform to the new SBCL bootstrap package
8 ;;;; system and then subsequently to address other cross-compiling
9 ;;;; bootstrap issues, SBCLification (e.g. DECLARE used to check
10 ;;;; argument types), and other maintenance. Whether or not it then
11 ;;;; supported all the environments implied by the reader conditionals
12 ;;;; in the source code (e.g. #!+CLOE-RUNTIME) before that
13 ;;;; modification, it sure doesn't now. It might perhaps, by blind
14 ;;;; luck, be appropriate for some other CMU-CL-derived system, but
15 ;;;; really it only attempts to be appropriate for SBCL.
17 ;;;; This software is derived from software originally released by the
18 ;;;; Massachusetts Institute of Technology and Symbolics, Inc. Copyright and
19 ;;;; release statements follow. Later modifications to the software are in
20 ;;;; the public domain and are provided with absolutely no warranty. See the
21 ;;;; COPYING and CREDITS files for more information.
23 ;;;; Portions of LOOP are Copyright (c) 1986 by the Massachusetts Institute
24 ;;;; of Technology. All Rights Reserved.
26 ;;;; Permission to use, copy, modify and distribute this software and its
27 ;;;; documentation for any purpose and without fee is hereby granted,
28 ;;;; provided that the M.I.T. copyright notice appear in all copies and that
29 ;;;; both that copyright notice and this permission notice appear in
30 ;;;; supporting documentation. The names "M.I.T." and "Massachusetts
31 ;;;; Institute of Technology" may not be used in advertising or publicity
32 ;;;; pertaining to distribution of the software without specific, written
33 ;;;; prior permission. Notice must be given in supporting documentation that
34 ;;;; copying distribution is by permission of M.I.T. M.I.T. makes no
35 ;;;; representations about the suitability of this software for any purpose.
36 ;;;; It is provided "as is" without express or implied warranty.
38 ;;;; Massachusetts Institute of Technology
39 ;;;; 77 Massachusetts Avenue
40 ;;;; Cambridge, Massachusetts 02139
41 ;;;; United States of America
44 ;;;; Portions of LOOP are Copyright (c) 1989, 1990, 1991, 1992 by Symbolics,
45 ;;;; Inc. All Rights Reserved.
47 ;;;; Permission to use, copy, modify and distribute this software and its
48 ;;;; documentation for any purpose and without fee is hereby granted,
49 ;;;; provided that the Symbolics copyright notice appear in all copies and
50 ;;;; that both that copyright notice and this permission notice appear in
51 ;;;; supporting documentation. The name "Symbolics" may not be used in
52 ;;;; advertising or publicity pertaining to distribution of the software
53 ;;;; without specific, written prior permission. Notice must be given in
54 ;;;; supporting documentation that copying distribution is by permission of
55 ;;;; Symbolics. Symbolics makes no representations about the suitability of
56 ;;;; this software for any purpose. It is provided "as is" without express
57 ;;;; or implied warranty.
59 ;;;; Symbolics, CLOE Runtime, and Minima are trademarks, and CLOE, Genera,
60 ;;;; and Zetalisp are registered trademarks of Symbolics, Inc.
63 ;;;; 8 New England Executive Park, East
64 ;;;; Burlington, Massachusetts 01803
65 ;;;; United States of America
68 (in-package "SB!LOOP")
70 ;;;; The design of this LOOP is intended to permit, using mostly the same
71 ;;;; kernel of code, up to three different "loop" macros:
73 ;;;; (1) The unextended, unextensible ANSI standard LOOP;
75 ;;;; (2) A clean "superset" extension of the ANSI LOOP which provides
76 ;;;; functionality similar to that of the old LOOP, but "in the style of"
77 ;;;; the ANSI LOOP. For instance, user-definable iteration paths, with a
78 ;;;; somewhat cleaned-up interface.
80 ;;;; (3) Extensions provided in another file which can make this LOOP
81 ;;;; kernel behave largely compatibly with the Genera-vintage LOOP macro,
82 ;;;; with only a small addition of code (instead of two whole, separate,
85 ;;;; Each of the above three LOOP variations can coexist in the same LISP
88 ;;;; KLUDGE: In SBCL, we only really use variant (1), and any generality
89 ;;;; for the other variants is wasted. -- WHN 20000121
91 ;;;; FIXME: the STEP-FUNCTION stuff in the code seems to've been
92 ;;;; intended to support code which was conditionalized with
93 ;;;; LOOP-PREFER-POP (not true on CMU CL) and which has since been
94 ;;;; removed. Thus, STEP-FUNCTION stuff could probably be removed too.
96 ;;;; miscellaneous environment things
98 (eval-when (:compile-toplevel :load-toplevel :execute)
99 (defvar *loop-real-data-type* 'real))
101 (eval-when (:compile-toplevel :load-toplevel :execute)
102 (defvar *loop-gentemp* nil)
103 (defun loop-gentemp (&optional (pref 'loopvar-))
105 (gentemp (string pref))
108 ;;; @@@@ The following form takes a list of variables and a form which
109 ;;; presumably references those variables, and wraps it somehow so that the
110 ;;; compiler does not consider those variables have been referenced. The intent
111 ;;; of this is that iteration variables can be flagged as unused by the
112 ;;; compiler, e.g. I in (loop for i from 1 to 10 do (print t)), since we will
113 ;;; tell it when a usage of it is "invisible" or "not to be considered".
115 ;;; We implicitly assume that a setq does not count as a reference. That is,
116 ;;; the kind of form generated for the above loop construct to step I,
118 ;;; `(SETQ I ,(HIDE-VARIABLE-REFERENCES '(I) '(1+ I))).
120 ;;; FIXME: This is a no-op except for Genera, now obsolete, so it
122 (defun hide-variable-references (variable-list form)
123 (declare (ignore variable-list))
126 ;;; @@@@ The following function takes a flag, a variable, and a form which
127 ;;; presumably references that variable, and wraps it somehow so that the
128 ;;; compiler does not consider that variable to have been referenced. The
129 ;;; intent of this is that iteration variables can be flagged as unused by the
130 ;;; compiler, e.g. I in (loop for i from 1 to 10 do (print t)), since we will
131 ;;; tell it when a usage of it is "invisible" or "not to be considered".
133 ;;; We implicitly assume that a setq does not count as a reference. That is,
134 ;;; the kind of form generated for the above loop construct to step I,
136 ;;; `(SETQ I ,(HIDE-VARIABLE-REFERENCES T 'I '(1+ I))).
138 ;;; Certain cases require that the "invisibility" of the reference be
139 ;;; conditional upon something. This occurs in cases of "named" variables (the
140 ;;; USING clause). For instance, we want IDX in (LOOP FOR E BEING THE
141 ;;; VECTOR-ELEMENTS OF V USING (INDEX IDX) ...) to be "invisible" when it is
142 ;;; stepped, so that the user gets informed if IDX is not referenced. However,
143 ;;; if no USING clause is present, we definitely do not want to be informed
144 ;;; that some gensym or other is not used.
146 ;;; It is easier for the caller to do this conditionally by passing a flag
147 ;;; (which happens to be the second value of NAMED-VARIABLE, q.v.) to this
148 ;;; function than for all callers to contain the conditional invisibility
151 ;;; FIXME: This is a no-op except for Genera, now obsolete, so it
153 (defun hide-variable-reference (really-hide variable form)
154 (declare (ignore really-hide variable))
157 ;;;; list collection macrology
159 (sb!int:defmacro-mundanely with-loop-list-collection-head
160 ((head-var tail-var &optional user-head-var) &body body)
161 (let ((l (and user-head-var (list (list user-head-var nil)))))
162 `(let* ((,head-var (list nil)) (,tail-var ,head-var) ,@l)
165 (sb!int:defmacro-mundanely loop-collect-rplacd
166 (&environment env (head-var tail-var &optional user-head-var) form)
167 (setq form (sb!xc:macroexpand form env))
168 (flet ((cdr-wrap (form n)
170 (do () ((<= n 4) (setq form `(,(case n
176 (setq form `(cddddr ,form) n (- n 4)))))
177 (let ((tail-form form) (ncdrs nil))
178 ;; Determine whether the form being constructed is a list of known
181 (cond ((eq (car form) 'list)
182 (setq ncdrs (1- (length (cdr form)))))
183 ((member (car form) '(list* cons))
184 (when (and (cddr form) (member (car (last form)) '(nil 'nil)))
185 (setq ncdrs (- (length (cdr form)) 2))))))
188 `(when (setf (cdr ,tail-var) ,tail-form)
189 (setq ,tail-var (last (cdr ,tail-var)))))
190 ((< ncdrs 0) (return-from loop-collect-rplacd nil))
192 ;; @@@@ Here we have a choice of two idioms:
193 ;; (RPLACD TAIL (SETQ TAIL TAIL-FORM))
194 ;; (SETQ TAIL (SETF (CDR TAIL) TAIL-FORM)).
195 ;; Genera and most others I have seen do better with the
197 `(rplacd ,tail-var (setq ,tail-var ,tail-form)))
198 (t `(setq ,tail-var ,(cdr-wrap `(setf (cdr ,tail-var)
201 ;; If not using locatives or something similar to update the
202 ;; user's head variable, we've got to set it... It's harmless
203 ;; to repeatedly set it unconditionally, and probably faster
208 (setq ,user-head-var (cdr ,head-var)))))
211 (sb!int:defmacro-mundanely loop-collect-answer (head-var
212 &optional user-head-var)
216 ;;;; maximization technology
219 The basic idea of all this minimax randomness here is that we have to
220 have constructed all uses of maximize and minimize to a particular
221 "destination" before we can decide how to code them. The goal is to not
222 have to have any kinds of flags, by knowing both that (1) the type is
223 something which we can provide an initial minimum or maximum value for
224 and (2) know that a MAXIMIZE and MINIMIZE are not being combined.
226 SO, we have a datastructure which we annotate with all sorts of things,
227 incrementally updating it as we generate loop body code, and then use
228 a wrapper and internal macros to do the coding when the loop has been
232 (defstruct (loop-minimax
233 (:constructor make-loop-minimax-internal)
243 (defvar *loop-minimax-type-infinities-alist*
244 ;; FIXME: Now that SBCL supports floating point infinities again, we
245 ;; should have floating point infinities here, as cmucl-2.4.8 did.
246 '((fixnum most-positive-fixnum most-negative-fixnum)))
248 (defun make-loop-minimax (answer-variable type)
249 (let ((infinity-data (cdr (assoc type
250 *loop-minimax-type-infinities-alist*
251 :test #'sb!xc:subtypep))))
252 (make-loop-minimax-internal
253 :answer-variable answer-variable
255 :temp-variable (loop-gentemp 'loop-maxmin-temp-)
256 :flag-variable (and (not infinity-data)
257 (loop-gentemp 'loop-maxmin-flag-))
259 :infinity-data infinity-data)))
261 (defun loop-note-minimax-operation (operation minimax)
262 (pushnew (the symbol operation) (loop-minimax-operations minimax))
263 (when (and (cdr (loop-minimax-operations minimax))
264 (not (loop-minimax-flag-variable minimax)))
265 (setf (loop-minimax-flag-variable minimax)
266 (loop-gentemp 'loop-maxmin-flag-)))
269 (sb!int:defmacro-mundanely with-minimax-value (lm &body body)
270 (let ((init (loop-typed-init (loop-minimax-type lm)))
271 (which (car (loop-minimax-operations lm)))
272 (infinity-data (loop-minimax-infinity-data lm))
273 (answer-var (loop-minimax-answer-variable lm))
274 (temp-var (loop-minimax-temp-variable lm))
275 (flag-var (loop-minimax-flag-variable lm))
276 (type (loop-minimax-type lm)))
278 `(let ((,answer-var ,init) (,temp-var ,init) (,flag-var nil))
279 (declare (type ,type ,answer-var ,temp-var))
281 `(let ((,answer-var ,(if (eq which 'min)
282 (first infinity-data)
283 (second infinity-data)))
285 (declare (type ,type ,answer-var ,temp-var))
288 (sb!int:defmacro-mundanely loop-accumulate-minimax-value (lm operation form)
289 (let* ((answer-var (loop-minimax-answer-variable lm))
290 (temp-var (loop-minimax-temp-variable lm))
291 (flag-var (loop-minimax-flag-variable lm))
293 (hide-variable-reference
294 t (loop-minimax-answer-variable lm)
298 ,temp-var ,answer-var))))
300 (setq ,temp-var ,form)
301 (when ,(if flag-var `(or (not ,flag-var) ,test) test)
302 (setq ,@(and flag-var `(,flag-var t))
303 ,answer-var ,temp-var)))))
305 ;;;; LOOP keyword tables
308 LOOP keyword tables are hash tables string keys and a test of EQUAL.
310 The actual descriptive/dispatch structure used by LOOP is called a "loop
311 universe" contains a few tables and parameterizations. The basic idea is
312 that we can provide a non-extensible ANSI-compatible loop environment,
313 an extensible ANSI-superset loop environment, and (for such environments
314 as CLOE) one which is "sufficiently close" to the old Genera-vintage
315 LOOP for use by old user programs without requiring all of the old LOOP
321 ;;; Compare two "tokens". The first is the frob out of *LOOP-SOURCE-CODE*,
322 ;;; the second a symbol to check against.
323 (defun loop-tequal (x1 x2)
324 (and (symbolp x1) (string= x1 x2)))
326 (defun loop-tassoc (kwd alist)
327 (and (symbolp kwd) (assoc kwd alist :test #'string=)))
329 (defun loop-tmember (kwd list)
330 (and (symbolp kwd) (member kwd list :test #'string=)))
332 (defun loop-lookup-keyword (loop-token table)
333 (and (symbolp loop-token)
334 (values (gethash (symbol-name loop-token) table))))
336 (sb!int:defmacro-mundanely loop-store-table-data (symbol table datum)
337 `(setf (gethash (symbol-name ,symbol) ,table) ,datum))
339 (defstruct (loop-universe
342 keywords ; hash table, value = (fn-name . extra-data)
343 iteration-keywords ; hash table, value = (fn-name . extra-data)
344 for-keywords ; hash table, value = (fn-name . extra-data)
345 path-keywords ; hash table, value = (fn-name . extra-data)
346 type-symbols ; hash table of type SYMBOLS, test EQ,
347 ; value = CL type specifier
348 type-keywords ; hash table of type STRINGS, test EQUAL,
349 ; value = CL type spec
350 ansi ; NIL, T, or :EXTENDED
351 implicit-for-required) ; see loop-hack-iteration
352 (sb!int:def!method print-object ((u loop-universe) stream)
353 (let ((string (case (loop-universe-ansi u)
356 (:extended "extended-ANSI")
357 (t (loop-universe-ansi u)))))
358 (print-unreadable-object (u stream :type t)
359 (write-string string stream))))
361 ;;; This is the "current" loop context in use when we are expanding a
362 ;;; loop. It gets bound on each invocation of LOOP.
363 (defvar *loop-universe*)
365 (defun make-standard-loop-universe (&key keywords for-keywords
366 iteration-keywords path-keywords
367 type-keywords type-symbols ansi)
368 (declare (type (member nil t :extended) ansi))
369 (flet ((maketable (entries)
370 (let* ((size (length entries))
371 (ht (make-hash-table :size (if (< size 10) 10 size)
374 (setf (gethash (symbol-name (car x)) ht) (cadr x)))
377 :keywords (maketable keywords)
378 :for-keywords (maketable for-keywords)
379 :iteration-keywords (maketable iteration-keywords)
380 :path-keywords (maketable path-keywords)
382 :implicit-for-required (not (null ansi))
383 :type-keywords (maketable type-keywords)
384 :type-symbols (let* ((size (length type-symbols))
385 (ht (make-hash-table :size (if (< size 10) 10 size)
387 (dolist (x type-symbols)
389 (setf (gethash x ht) x)
390 (setf (gethash (car x) ht) (cadr x))))
395 (defvar *loop-destructuring-hooks*
398 "If not NIL, this must be a list of two things:
399 a LET-like macro, and a SETQ-like macro, which perform LOOP-style destructuring.")
401 (defun loop-make-psetq (frobs)
405 (if (null (cddr frobs)) (cadr frobs)
406 `(prog1 ,(cadr frobs)
407 ,(loop-make-psetq (cddr frobs))))))))
409 (defun loop-make-desetq (var-val-pairs)
410 (if (null var-val-pairs)
412 (cons (if *loop-destructuring-hooks*
413 (cadr *loop-destructuring-hooks*)
417 (defvar *loop-desetq-temporary*
418 (make-symbol "LOOP-DESETQ-TEMP"))
420 (sb!int:defmacro-mundanely loop-really-desetq (&environment env
422 (labels ((find-non-null (var)
423 ;; see whether there's any non-null thing here
424 ;; recurse if the list element is itself a list
425 (do ((tail var)) ((not (consp tail)) tail)
426 (when (find-non-null (pop tail)) (return t))))
427 (loop-desetq-internal (var val &optional temp)
428 ;; returns a list of actions to be performed
432 ;; don't lose possible side-effects
433 (if (eq (car val) 'prog1)
434 ;; these can come from psetq or desetq below.
435 ;; throw away the value, keep the side-effects.
436 ;;Special case is for handling an expanded POP.
437 (mapcan #'(lambda (x)
439 (or (not (eq (car x) 'car))
440 (not (symbolp (cadr x)))
441 (not (symbolp (setq x (sb!xc:macroexpand x env)))))
446 (let* ((car (car var))
448 (car-non-null (find-non-null car))
449 (cdr-non-null (find-non-null cdr)))
450 (when (or car-non-null cdr-non-null)
453 (temp (or temp *loop-desetq-temporary*))
454 (body `(,@(loop-desetq-internal car
456 (setq ,temp (cdr ,temp))
457 ,@(loop-desetq-internal cdr
461 `(,@(unless (eq temp val)
462 `((setq ,temp ,val)))
464 `((let ((,temp ,val))
467 (loop-desetq-internal car `(car ,val) temp)))))
470 `((setq ,var ,val)))))))
472 ((null var-val-pairs)
473 (if (null (cdr actions)) (car actions) `(progn ,@(nreverse actions))))
474 (setq actions (revappend
475 (loop-desetq-internal (pop var-val-pairs)
479 ;;;; LOOP-local variables
481 ;;; This is the "current" pointer into the LOOP source code.
482 (defvar *loop-source-code*)
484 ;;; This is the pointer to the original, for things like NAMED that
485 ;;; insist on being in a particular position
486 (defvar *loop-original-source-code*)
488 ;;; This is *loop-source-code* as of the "last" clause. It is used
489 ;;; primarily for generating error messages (see loop-error, loop-warn).
490 (defvar *loop-source-context*)
492 ;;; list of names for the LOOP, supplied by the NAMED clause
493 (defvar *loop-names*)
495 ;;; The macroexpansion environment given to the macro.
496 (defvar *loop-macro-environment*)
498 ;;; This holds variable names specified with the USING clause.
499 ;;; See LOOP-NAMED-VARIABLE.
500 (defvar *loop-named-variables*)
502 ;;; LETlist-like list being accumulated for one group of parallel bindings.
503 (defvar *loop-variables*)
505 ;;; list of declarations being accumulated in parallel with *LOOP-VARIABLES*
506 (defvar *loop-declarations*)
508 ;;; This is used by LOOP for destructuring binding, if it is doing
509 ;;; that itself. See LOOP-MAKE-VARIABLE.
510 (defvar *loop-desetq-crocks*)
512 ;;; list of wrapping forms, innermost first, which go immediately
513 ;;; inside the current set of parallel bindings being accumulated in
514 ;;; *LOOP-VARIABLES*. The wrappers are appended onto a body. E.g.,
515 ;;; this list could conceivably have as its value
516 ;;; ((WITH-OPEN-FILE (G0001 G0002 ...))),
517 ;;; with G0002 being one of the bindings in *LOOP-VARIABLES* (This is
518 ;;; why the wrappers go inside of the variable bindings).
519 (defvar *loop-wrappers*)
521 ;;; This accumulates lists of previous values of *LOOP-VARIABLES* and
522 ;;; the other lists above, for each new nesting of bindings. See
524 (defvar *loop-bind-stack*)
526 ;;; This is simply a list of LOOP iteration variables, used for
527 ;;; checking for duplications.
528 (defvar *loop-iteration-variables*)
530 ;;; list of prologue forms of the loop, accumulated in reverse order
531 (defvar *loop-prologue*)
533 (defvar *loop-before-loop*)
535 (defvar *loop-after-body*)
537 ;;; This is T if we have emitted any body code, so that iteration
538 ;;; driving clauses can be disallowed. This is not strictly the same
539 ;;; as checking *LOOP-BODY*, because we permit some clauses such as
540 ;;; RETURN to not be considered "real" body (so as to permit the user
541 ;;; to "code" an abnormal return value "in loop").
542 (defvar *loop-emitted-body*)
544 ;;; list of epilogue forms (supplied by FINALLY generally), accumulated
546 (defvar *loop-epilogue*)
548 ;;; list of epilogue forms which are supplied after the above "user"
549 ;;; epilogue. "Normal" termination return values are provide by
550 ;;; putting the return form in here. Normally this is done using
551 ;;; LOOP-EMIT-FINAL-VALUE, q.v.
552 (defvar *loop-after-epilogue*)
554 ;;; the "culprit" responsible for supplying a final value from the
555 ;;; loop. This is so LOOP-EMIT-FINAL-VALUE can moan about multiple
556 ;;; return values being supplied.
557 (defvar *loop-final-value-culprit*)
559 ;;; If this is true, we are in some branch of a conditional. Some
560 ;;; clauses may be disallowed.
561 (defvar *loop-inside-conditional*)
563 ;;; If not NIL, this is a temporary bound around the loop for holding
564 ;;; the temporary value for "it" in things like "when (f) collect it".
565 ;;; It may be used as a supertemporary by some other things.
566 (defvar *loop-when-it-variable*)
568 ;;; Sometimes we decide we need to fold together parts of the loop,
569 ;;; but some part of the generated iteration code is different for the
570 ;;; first and remaining iterations. This variable will be the
571 ;;; temporary which is the flag used in the loop to tell whether we
572 ;;; are in the first or remaining iterations.
573 (defvar *loop-never-stepped-variable*)
575 ;;; list of all the value-accumulation descriptor structures in the
576 ;;; loop. See LOOP-GET-COLLECTION-INFO.
577 (defvar *loop-collection-cruft*) ; for multiple COLLECTs (etc.)
579 ;;;; code analysis stuff
581 (defun loop-constant-fold-if-possible (form &optional expected-type)
582 (let ((new-form form) (constantp nil) (constant-value nil))
583 (when (setq constantp (constantp new-form))
584 (setq constant-value (eval new-form)))
585 (when (and constantp expected-type)
586 (unless (sb!xc:typep constant-value expected-type)
587 (loop-warn "The form ~S evaluated to ~S, which was not of the anticipated type ~S."
588 form constant-value expected-type)
589 (setq constantp nil constant-value nil)))
590 (values new-form constantp constant-value)))
592 (defun loop-constantp (form)
595 ;;;; LOOP iteration optimization
597 (defvar *loop-duplicate-code*
600 (defvar *loop-iteration-flag-variable*
601 (make-symbol "LOOP-NOT-FIRST-TIME"))
603 (defun loop-code-duplication-threshold (env)
604 (declare (ignore env))
605 (let (;; If we could read optimization declaration information (as
606 ;; with the DECLARATION-INFORMATION function (present in
607 ;; CLTL2, removed from ANSI standard) we could set these
608 ;; values flexibly. Without DECLARATION-INFORMATION, we have
609 ;; to set them to constants.
612 (+ 40 (* (- speed space) 10))))
614 (sb!int:defmacro-mundanely loop-body (&environment env
620 &aux rbefore rafter flagvar)
621 (unless (= (length before-loop) (length after-loop))
622 (error "LOOP-BODY called with non-synched before- and after-loop lists"))
623 ;;All our work is done from these copies, working backwards from the end:
624 (setq rbefore (reverse before-loop) rafter (reverse after-loop))
631 (member (car x) '(go return return-from)))
634 (pify (l) (if (null (cdr l)) (car l) `(progn ,@l)))
636 (let ((form `(tagbody
637 ,@(psimp (append prologue (nreverse rbefore)))
639 ,@(psimp (append main-body
643 ,@(psimp epilogue))))
644 (if flagvar `(let ((,flagvar nil)) ,form) form))))
645 (when (or *loop-duplicate-code* (not rbefore))
646 (return-from loop-body (makebody)))
647 ;; This outer loop iterates once for each not-first-time flag test
648 ;; generated plus once more for the forms that don't need a flag test
649 (do ((threshold (loop-code-duplication-threshold env))) (nil)
650 (declare (fixnum threshold))
651 ;; Go backwards from the ends of before-loop and after-loop merging all
652 ;; the equivalent forms into the body.
653 (do () ((or (null rbefore) (not (equal (car rbefore) (car rafter)))))
654 (push (pop rbefore) main-body)
656 (unless rbefore (return (makebody)))
657 ;; The first forms in RBEFORE & RAFTER (which are the chronologically
658 ;; last forms in the list) differ, therefore they cannot be moved
659 ;; into the main body. If everything that chronologically precedes
660 ;; them either differs or is equal but is okay to duplicate, we can
661 ;; just put all of rbefore in the prologue and all of rafter after
662 ;; the body. Otherwise, there is something that is not okay to
663 ;; duplicate, so it and everything chronologically after it in
664 ;; rbefore and rafter must go into the body, with a flag test to
665 ;; distinguish the first time around the loop from later times.
666 ;; What chronologically precedes the non-duplicatable form will
667 ;; be handled the next time around the outer loop.
668 (do ((bb rbefore (cdr bb))
673 ((null bb) (return-from loop-body (makebody))) ; Did it.
674 (cond ((not (equal (car bb) (car aa))) (setq lastdiff bb count 0))
675 ((or (not (setq inc (estimate-code-size (car bb) env)))
676 (> (incf count inc) threshold))
677 ;; Ok, we have found a non-duplicatable piece of code.
678 ;; Everything chronologically after it must be in the
679 ;; central body. Everything chronologically at and
680 ;; after LASTDIFF goes into the central body under a
682 (let ((then nil) (else nil))
684 (push (pop rbefore) else)
685 (push (pop rafter) then)
686 (when (eq rbefore (cdr lastdiff)) (return)))
688 (push `(setq ,(setq flagvar *loop-iteration-flag-variable*)
691 (push `(if ,flagvar ,(pify (psimp then)) ,(pify (psimp else)))
693 ;; Everything chronologically before lastdiff until the
694 ;; non-duplicatable form (CAR BB) is the same in
695 ;; RBEFORE and RAFTER, so just copy it into the body.
698 (push (pop rbefore) main-body)
699 (when (eq rbefore (cdr bb)) (return)))
702 (defun duplicatable-code-p (expr env)
704 (let ((ans (estimate-code-size expr env)))
705 (declare (fixnum ans))
706 ;; @@@@ Use (DECLARATION-INFORMATION 'OPTIMIZE ENV) here to get an
707 ;; alist of optimize quantities back to help quantify how much code we
708 ;; are willing to duplicate.
711 (defvar *special-code-sizes*
712 '((return 0) (progn 0)
713 (null 1) (not 1) (eq 1) (car 1) (cdr 1)
714 (when 1) (unless 1) (if 1)
715 (caar 2) (cadr 2) (cdar 2) (cddr 2)
716 (caaar 3) (caadr 3) (cadar 3) (caddr 3)
717 (cdaar 3) (cdadr 3) (cddar 3) (cdddr 3)
718 (caaaar 4) (caaadr 4) (caadar 4) (caaddr 4)
719 (cadaar 4) (cadadr 4) (caddar 4) (cadddr 4)
720 (cdaaar 4) (cdaadr 4) (cdadar 4) (cdaddr 4)
721 (cddaar 4) (cddadr 4) (cdddar 4) (cddddr 4)))
723 (defvar *estimate-code-size-punt*
727 labels lambda let let* locally
728 macrolet multiple-value-bind
735 (defun destructuring-size (x)
736 (do ((x x (cdr x)) (n 0 (+ (destructuring-size (car x)) n)))
737 ((atom x) (+ n (if (null x) 0 1)))))
739 (defun estimate-code-size (x env)
740 (catch 'estimate-code-size
741 (estimate-code-size-1 x env)))
743 (defun estimate-code-size-1 (x env)
744 (flet ((list-size (l)
747 (dolist (x l n) (incf n (estimate-code-size-1 x env))))))
748 ;;@@@@ ???? (declare (function list-size (list) fixnum))
749 (cond ((constantp x) 1)
750 ((symbolp x) (multiple-value-bind (new-form expanded-p)
751 (sb!xc:macroexpand-1 x env)
753 (estimate-code-size-1 new-form env)
755 ((atom x) 1) ;; ??? self-evaluating???
757 (let ((fn (car x)) (tem nil) (n 0))
758 (declare (symbol fn) (fixnum n))
759 (macrolet ((f (overhead &optional (args nil args-p))
760 `(the fixnum (+ (the fixnum ,overhead)
762 (list-size ,(if args-p
765 (cond ((setq tem (get fn 'estimate-code-size))
768 (t (funcall tem x env))))
769 ((setq tem (assoc fn *special-code-sizes*))
772 (dolist (clause (cdr x) n)
773 (incf n (list-size clause)) (incf n)))
775 (do ((l (cdr x) (cdr l))) ((null l) n)
777 (destructuring-size (car l))
778 (estimate-code-size-1 (cadr l) env)))))
779 ((member fn '(setq psetq))
780 (do ((l (cdr x) (cdr l))) ((null l) n)
781 (setq n (+ n (estimate-code-size-1 (cadr l) env) 1))))
784 ;; This skirts the issue of implementationally-defined
785 ;; lambda macros by recognizing CL function names and
787 (if (or (symbolp (cadr x))
788 (and (consp (cadr x)) (eq (caadr x) 'setf)))
790 (throw 'duplicatable-code-p nil)))
791 ((eq fn 'multiple-value-setq)
792 (f (length (second x)) (cddr x)))
793 ((eq fn 'return-from)
794 (1+ (estimate-code-size-1 (third x) env)))
795 ((or (special-operator-p fn)
796 (member fn *estimate-code-size-punt*))
797 (throw 'estimate-code-size nil))
798 (t (multiple-value-bind (new-form expanded-p)
799 (sb!xc:macroexpand-1 x env)
801 (estimate-code-size-1 new-form env)
803 (t (throw 'estimate-code-size nil)))))
807 (defun loop-context ()
808 (do ((l *loop-source-context* (cdr l)) (new nil (cons (car l) new)))
809 ((eq l (cdr *loop-source-code*)) (nreverse new))))
811 (defun loop-error (format-string &rest format-args)
812 (error "~?~%current LOOP context:~{ ~S~}."
817 (defun loop-warn (format-string &rest format-args)
818 (warn "~?~%current LOOP context:~{ ~S~}."
823 (defun loop-check-data-type (specified-type required-type
824 &optional (default-type required-type))
825 (if (null specified-type)
827 (multiple-value-bind (a b) (sb!xc:subtypep specified-type required-type)
829 (loop-warn "LOOP couldn't verify that ~S is a subtype of the required type ~S."
830 specified-type required-type))
832 (loop-error "The specified data type ~S is not a subtype of ~S."
833 specified-type required-type)))
836 (defun loop-translate (*loop-source-code*
837 *loop-macro-environment*
839 (let ((*loop-original-source-code* *loop-source-code*)
840 (*loop-source-context* nil)
841 (*loop-iteration-variables* nil)
842 (*loop-variables* nil)
843 (*loop-named-variables* nil)
844 (*loop-declarations* nil)
845 (*loop-desetq-crocks* nil)
846 (*loop-bind-stack* nil)
847 (*loop-prologue* nil)
848 (*loop-wrappers* nil)
849 (*loop-before-loop* nil)
851 (*loop-emitted-body* nil)
852 (*loop-after-body* nil)
853 (*loop-epilogue* nil)
854 (*loop-after-epilogue* nil)
855 (*loop-final-value-culprit* nil)
856 (*loop-inside-conditional* nil)
857 (*loop-when-it-variable* nil)
858 (*loop-never-stepped-variable* nil)
860 (*loop-collection-cruft* nil))
861 (loop-iteration-driver)
863 (let ((answer `(loop-body
864 ,(nreverse *loop-prologue*)
865 ,(nreverse *loop-before-loop*)
866 ,(nreverse *loop-body*)
867 ,(nreverse *loop-after-body*)
868 ,(nreconc *loop-epilogue*
869 (nreverse *loop-after-epilogue*)))))
871 (setq answer `(block ,(pop *loop-names*) ,answer))
872 (unless *loop-names* (return nil)))
873 (dolist (entry *loop-bind-stack*)
874 (let ((vars (first entry))
875 (dcls (second entry))
876 (crocks (third entry))
877 (wrappers (fourth entry)))
879 (setq answer (append w (list answer))))
880 (when (or vars dcls crocks)
881 (let ((forms (list answer)))
882 ;;(when crocks (push crocks forms))
883 (when dcls (push `(declare ,@dcls) forms))
884 (setq answer `(,(cond ((not vars) 'locally)
885 (*loop-destructuring-hooks*
886 (first *loop-destructuring-hooks*))
891 `((destructuring-bind ,@crocks
896 (defun loop-iteration-driver ()
897 (do () ((null *loop-source-code*))
898 (let ((keyword (car *loop-source-code*)) (tem nil))
899 (cond ((not (symbolp keyword))
900 (loop-error "~S found where LOOP keyword expected" keyword))
901 (t (setq *loop-source-context* *loop-source-code*)
904 (loop-lookup-keyword keyword
905 (loop-universe-keywords
907 ;; It's a "miscellaneous" toplevel LOOP keyword (DO,
908 ;; COLLECT, NAMED, etc.)
909 (apply (symbol-function (first tem)) (rest tem)))
911 (loop-lookup-keyword keyword
912 (loop-universe-iteration-keywords *loop-universe*)))
913 (loop-hack-iteration tem))
914 ((loop-tmember keyword '(and else))
915 ;; The alternative is to ignore it, i.e. let it go
916 ;; around to the next keyword...
917 (loop-error "secondary clause misplaced at top level in LOOP macro: ~S ~S ~S ..."
919 (car *loop-source-code*)
920 (cadr *loop-source-code*)))
921 (t (loop-error "unknown LOOP keyword: ~S" keyword))))))))
923 (defun loop-pop-source ()
924 (if *loop-source-code*
925 (pop *loop-source-code*)
926 (loop-error "LOOP source code ran out when another token was expected.")))
928 (defun loop-get-progn ()
929 (do ((forms (list (loop-pop-source)) (cons (loop-pop-source) forms))
930 (nextform (car *loop-source-code*) (car *loop-source-code*)))
932 (if (null (cdr forms)) (car forms) (cons 'progn (nreverse forms))))))
934 (defun loop-get-form ()
935 (if *loop-source-code*
937 (loop-error "LOOP code ran out where a form was expected.")))
939 (defun loop-construct-return (form)
940 `(return-from ,(car *loop-names*) ,form))
942 (defun loop-pseudo-body (form)
943 (cond ((or *loop-emitted-body* *loop-inside-conditional*)
944 (push form *loop-body*))
945 (t (push form *loop-before-loop*) (push form *loop-after-body*))))
947 (defun loop-emit-body (form)
948 (setq *loop-emitted-body* t)
949 (loop-pseudo-body form))
951 (defun loop-emit-final-value (form)
952 (push (loop-construct-return form) *loop-after-epilogue*)
953 (when *loop-final-value-culprit*
954 (loop-warn "The LOOP clause is providing a value for the iteration,~@
955 however one was already established by a ~S clause."
956 *loop-final-value-culprit*))
957 (setq *loop-final-value-culprit* (car *loop-source-context*)))
959 (defun loop-disallow-conditional (&optional kwd)
960 (when *loop-inside-conditional*
961 (loop-error "~:[This LOOP~;The LOOP ~:*~S~] clause is not permitted inside a conditional." kwd)))
965 (defun loop-typed-init (data-type)
966 (when (and data-type (sb!xc:subtypep data-type 'number))
967 (if (or (sb!xc:subtypep data-type 'float)
968 (sb!xc:subtypep data-type '(complex float)))
972 (defun loop-optional-type (&optional variable)
973 ;; No variable specified implies that no destructuring is permissible.
974 (and *loop-source-code* ; Don't get confused by NILs..
975 (let ((z (car *loop-source-code*)))
976 (cond ((loop-tequal z 'of-type)
977 ;; This is the syntactically unambigous form in that the form
978 ;; of the type specifier does not matter. Also, it is assumed
979 ;; that the type specifier is unambiguously, and without need
980 ;; of translation, a common lisp type specifier or pattern
981 ;; (matching the variable) thereof.
986 ;; This is the (sort of) "old" syntax, even though we didn't
987 ;; used to support all of these type symbols.
988 (let ((type-spec (or (gethash z
989 (loop-universe-type-symbols
991 (gethash (symbol-name z)
992 (loop-universe-type-keywords
998 ;; This is our sort-of old syntax. But this is only valid for
999 ;; when we are destructuring, so we will be compulsive (should
1000 ;; we really be?) and require that we in fact be doing variable
1001 ;; destructuring here. We must translate the old keyword
1002 ;; pattern typespec into a fully-specified pattern of real type
1004 (if (consp variable)
1007 "~S found where a LOOP keyword, LOOP type keyword, or LOOP type pattern expected"
1009 (loop-error "~S found where a LOOP keyword or LOOP type keyword expected" z))
1011 (labels ((translate (k v)
1012 (cond ((null k) nil)
1016 (loop-universe-type-symbols
1018 (gethash (symbol-name k)
1019 (loop-universe-type-keywords
1022 "The destructuring type pattern ~S contains the unrecognized type keyword ~S."
1027 "The destructuring type pattern ~S doesn't match the variable pattern ~S."
1029 (t (cons (translate (car k) (car v))
1030 (translate (cdr k) (cdr v))))))
1034 (cons (replicate typ (car v))
1035 (replicate typ (cdr v))))))
1036 (translate z variable)))))))
1040 (defun loop-bind-block ()
1041 (when (or *loop-variables* *loop-declarations* *loop-wrappers*)
1042 (push (list (nreverse *loop-variables*)
1044 *loop-desetq-crocks*
1047 (setq *loop-variables* nil
1048 *loop-declarations* nil
1049 *loop-desetq-crocks* nil
1050 *loop-wrappers* nil)))
1052 (defun loop-make-variable (name initialization dtype
1053 &optional iteration-variable-p)
1055 (cond ((not (null initialization))
1056 (push (list (setq name (loop-gentemp 'loop-ignore-))
1059 (push `(ignore ,name) *loop-declarations*))))
1061 (cond (iteration-variable-p
1062 (if (member name *loop-iteration-variables*)
1063 (loop-error "duplicated LOOP iteration variable ~S" name)
1064 (push name *loop-iteration-variables*)))
1065 ((assoc name *loop-variables*)
1066 (loop-error "duplicated variable ~S in LOOP parallel binding"
1068 (unless (symbolp name)
1069 (loop-error "bad variable ~S somewhere in LOOP" name))
1070 (loop-declare-variable name dtype)
1071 ;; We use ASSOC on this list to check for duplications (above),
1072 ;; so don't optimize out this list:
1073 (push (list name (or initialization (loop-typed-init dtype)))
1076 (cond (*loop-destructuring-hooks*
1077 (loop-declare-variable name dtype)
1078 (push (list name initialization) *loop-variables*))
1079 (t (let ((newvar (loop-gentemp 'loop-destructure-)))
1080 (push (list newvar initialization) *loop-variables*)
1081 ;; *LOOP-DESETQ-CROCKS* gathered in reverse order.
1082 (setq *loop-desetq-crocks*
1083 (list* name newvar *loop-desetq-crocks*))))))
1084 (t (let ((tcar nil) (tcdr nil))
1085 (if (atom dtype) (setq tcar (setq tcdr dtype))
1086 (setq tcar (car dtype) tcdr (cdr dtype)))
1087 (loop-make-variable (car name) nil tcar iteration-variable-p)
1088 (loop-make-variable (cdr name) nil tcdr iteration-variable-p))))
1091 (defun loop-make-iteration-variable (name initialization dtype)
1092 (loop-make-variable name initialization dtype t))
1094 (defun loop-declare-variable (name dtype)
1095 (cond ((or (null name) (null dtype) (eq dtype t)) nil)
1097 (unless (sb!xc:subtypep t dtype)
1098 (let ((dtype (let ((init (loop-typed-init dtype)))
1099 (if (sb!xc:typep init dtype)
1101 `(or (member ,init) ,dtype)))))
1102 (push `(type ,dtype ,name) *loop-declarations*))))
1104 (cond ((consp dtype)
1105 (loop-declare-variable (car name) (car dtype))
1106 (loop-declare-variable (cdr name) (cdr dtype)))
1107 (t (loop-declare-variable (car name) dtype)
1108 (loop-declare-variable (cdr name) dtype))))
1109 (t (error "invalid LOOP variable passed in: ~S" name))))
1111 (defun loop-maybe-bind-form (form data-type)
1112 (if (loop-constantp form)
1114 (loop-make-variable (loop-gentemp 'loop-bind-) form data-type)))
1116 (defun loop-do-if (for negatep)
1117 (let ((form (loop-get-form)) (*loop-inside-conditional* t) (it-p nil))
1118 (flet ((get-clause (for)
1119 (do ((body nil)) (nil)
1120 (let ((key (car *loop-source-code*)) (*loop-body* nil) data)
1121 (cond ((not (symbolp key))
1123 "~S found where keyword expected getting LOOP clause after ~S"
1125 (t (setq *loop-source-context* *loop-source-code*)
1127 (when (loop-tequal (car *loop-source-code*) 'it)
1128 (setq *loop-source-code*
1131 (loop-when-it-variable)))
1132 (cdr *loop-source-code*))))
1133 (cond ((or (not (setq data (loop-lookup-keyword
1134 key (loop-universe-keywords *loop-universe*))))
1135 (progn (apply (symbol-function (car data))
1137 (null *loop-body*)))
1139 "~S does not introduce a LOOP clause that can follow ~S."
1141 (t (setq body (nreconc *loop-body* body)))))))
1142 (if (loop-tequal (car *loop-source-code*) :and)
1144 (return (if (cdr body)
1145 `(progn ,@(nreverse body))
1147 (let ((then (get-clause for))
1148 (else (when (loop-tequal (car *loop-source-code*) :else)
1150 (list (get-clause :else)))))
1151 (when (loop-tequal (car *loop-source-code*) :end)
1153 (when it-p (setq form `(setq ,it-p ,form)))
1155 `(if ,(if negatep `(not ,form) form)
1159 (defun loop-do-initially ()
1160 (loop-disallow-conditional :initially)
1161 (push (loop-get-progn) *loop-prologue*))
1163 (defun loop-do-finally ()
1164 (loop-disallow-conditional :finally)
1165 (push (loop-get-progn) *loop-epilogue*))
1167 (defun loop-do-do ()
1168 (loop-emit-body (loop-get-progn)))
1170 (defun loop-do-named ()
1171 (let ((name (loop-pop-source)))
1172 (unless (symbolp name)
1173 (loop-error "~S is an invalid name for your LOOP" name))
1174 (when (or *loop-before-loop* *loop-body* *loop-after-epilogue* *loop-inside-conditional*)
1175 (loop-error "The NAMED ~S clause occurs too late." name))
1177 (loop-error "You may only use one NAMED clause in your loop: NAMED ~S ... NAMED ~S."
1178 (car *loop-names*) name))
1179 (setq *loop-names* (list name nil))))
1181 (defun loop-do-return ()
1182 (loop-pseudo-body (loop-construct-return (loop-get-form))))
1184 ;;;; value accumulation: LIST
1186 (defstruct (loop-collector
1194 (data nil)) ;collector-specific data
1196 (defun loop-get-collection-info (collector class default-type)
1197 (let ((form (loop-get-form))
1198 (dtype (and (not (loop-universe-ansi *loop-universe*)) (loop-optional-type)))
1199 (name (when (loop-tequal (car *loop-source-code*) 'into)
1201 (loop-pop-source))))
1202 (when (not (symbolp name))
1203 (loop-error "The value accumulation recipient name, ~S, is not a symbol." name))
1205 (setq dtype (or (loop-optional-type) default-type)))
1206 (let ((cruft (find (the symbol name) *loop-collection-cruft*
1207 :key #'loop-collector-name)))
1209 (push (setq cruft (make-loop-collector
1210 :name name :class class
1211 :history (list collector) :dtype dtype))
1212 *loop-collection-cruft*))
1213 (t (unless (eq (loop-collector-class cruft) class)
1215 "incompatible kinds of LOOP value accumulation specified for collecting~@
1216 ~:[as the value of the LOOP~;~:*INTO ~S~]: ~S and ~S"
1217 name (car (loop-collector-history cruft)) collector))
1218 (unless (equal dtype (loop-collector-dtype cruft))
1220 "unequal datatypes specified in different LOOP value accumulations~@
1222 name dtype (loop-collector-dtype cruft))
1223 (when (eq (loop-collector-dtype cruft) t)
1224 (setf (loop-collector-dtype cruft) dtype)))
1225 (push collector (loop-collector-history cruft))))
1226 (values cruft form))))
1228 (defun loop-list-collection (specifically) ; NCONC, LIST, or APPEND
1229 (multiple-value-bind (lc form)
1230 (loop-get-collection-info specifically 'list 'list)
1231 (let ((tempvars (loop-collector-tempvars lc)))
1233 (setf (loop-collector-tempvars lc)
1234 (setq tempvars (list* (loop-gentemp 'loop-list-head-)
1235 (loop-gentemp 'loop-list-tail-)
1236 (and (loop-collector-name lc)
1237 (list (loop-collector-name lc))))))
1238 (push `(with-loop-list-collection-head ,tempvars) *loop-wrappers*)
1239 (unless (loop-collector-name lc)
1240 (loop-emit-final-value `(loop-collect-answer ,(car tempvars)
1241 ,@(cddr tempvars)))))
1243 (list (setq form `(list ,form)))
1245 (append (unless (and (consp form) (eq (car form) 'list))
1246 (setq form `(copy-list ,form)))))
1247 (loop-emit-body `(loop-collect-rplacd ,tempvars ,form)))))
1249 ;;;; value accumulation: MAX, MIN, SUM, COUNT
1251 (defun loop-sum-collection (specifically required-type default-type);SUM, COUNT
1252 (multiple-value-bind (lc form)
1253 (loop-get-collection-info specifically 'sum default-type)
1254 (loop-check-data-type (loop-collector-dtype lc) required-type)
1255 (let ((tempvars (loop-collector-tempvars lc)))
1257 (setf (loop-collector-tempvars lc)
1258 (setq tempvars (list (loop-make-variable
1259 (or (loop-collector-name lc)
1260 (loop-gentemp 'loop-sum-))
1261 nil (loop-collector-dtype lc)))))
1262 (unless (loop-collector-name lc)
1263 (loop-emit-final-value (car (loop-collector-tempvars lc)))))
1265 (if (eq specifically 'count)
1267 (setq ,(car tempvars)
1268 ,(hide-variable-reference t
1270 `(1+ ,(car tempvars)))))
1271 `(setq ,(car tempvars)
1272 (+ ,(hide-variable-reference t
1277 (defun loop-maxmin-collection (specifically)
1278 (multiple-value-bind (lc form)
1279 (loop-get-collection-info specifically 'maxmin *loop-real-data-type*)
1280 (loop-check-data-type (loop-collector-dtype lc) *loop-real-data-type*)
1281 (let ((data (loop-collector-data lc)))
1283 (setf (loop-collector-data lc)
1284 (setq data (make-loop-minimax
1285 (or (loop-collector-name lc)
1286 (loop-gentemp 'loop-maxmin-))
1287 (loop-collector-dtype lc))))
1288 (unless (loop-collector-name lc)
1289 (loop-emit-final-value (loop-minimax-answer-variable data))))
1290 (loop-note-minimax-operation specifically data)
1291 (push `(with-minimax-value ,data) *loop-wrappers*)
1292 (loop-emit-body `(loop-accumulate-minimax-value ,data
1296 ;;;; value accumulation: aggregate booleans
1298 ;;; handling the ALWAYS and NEVER loop keywords
1300 ;;; Under ANSI these are not permitted to appear under conditionalization.
1301 (defun loop-do-always (restrictive negate)
1302 (let ((form (loop-get-form)))
1303 (when restrictive (loop-disallow-conditional))
1304 (loop-emit-body `(,(if negate 'when 'unless) ,form
1305 ,(loop-construct-return nil)))
1306 (loop-emit-final-value t)))
1308 ;;; handling the THEREIS loop keyword
1310 ;;; Under ANSI this is not permitted to appear under conditionalization.
1311 (defun loop-do-thereis (restrictive)
1312 (when restrictive (loop-disallow-conditional))
1313 (loop-emit-body `(when (setq ,(loop-when-it-variable) ,(loop-get-form))
1314 ,(loop-construct-return *loop-when-it-variable*))))
1316 (defun loop-do-while (negate kwd &aux (form (loop-get-form)))
1317 (loop-disallow-conditional kwd)
1318 (loop-pseudo-body `(,(if negate 'when 'unless) ,form (go end-loop))))
1320 (defun loop-do-with ()
1321 (loop-disallow-conditional :with)
1322 (do ((var) (val) (dtype)) (nil)
1323 (setq var (loop-pop-source)
1324 dtype (loop-optional-type var)
1325 val (cond ((loop-tequal (car *loop-source-code*) :=)
1329 (loop-make-variable var val dtype)
1330 (if (loop-tequal (car *loop-source-code*) :and)
1332 (return (loop-bind-block)))))
1334 ;;;; the iteration driver
1336 (defun loop-hack-iteration (entry)
1337 (flet ((make-endtest (list-of-forms)
1338 (cond ((null list-of-forms) nil)
1339 ((member t list-of-forms) '(go end-loop))
1340 (t `(when ,(if (null (cdr (setq list-of-forms
1341 (nreverse list-of-forms))))
1343 (cons 'or list-of-forms))
1345 (do ((pre-step-tests nil)
1347 (post-step-tests nil)
1349 (pre-loop-pre-step-tests nil)
1350 (pre-loop-steps nil)
1351 (pre-loop-post-step-tests nil)
1352 (pre-loop-pseudo-steps nil)
1355 ;; Note that we collect endtests in reverse order, but steps in correct
1356 ;; order. MAKE-ENDTEST does the nreverse for us.
1357 (setq tem (setq data
1358 (apply (symbol-function (first entry)) (rest entry))))
1359 (and (car tem) (push (car tem) pre-step-tests))
1360 (setq steps (nconc steps (copy-list (car (setq tem (cdr tem))))))
1361 (and (car (setq tem (cdr tem))) (push (car tem) post-step-tests))
1363 (nconc pseudo-steps (copy-list (car (setq tem (cdr tem))))))
1364 (setq tem (cdr tem))
1365 (when *loop-emitted-body*
1366 (loop-error "iteration in LOOP follows body code"))
1367 (unless tem (setq tem data))
1368 (when (car tem) (push (car tem) pre-loop-pre-step-tests))
1369 ;; FIXME: This (SETF FOO (NCONC FOO BAR)) idiom appears often enough
1370 ;; that it might be worth making it into an NCONCF macro.
1371 (setq pre-loop-steps
1372 (nconc pre-loop-steps (copy-list (car (setq tem (cdr tem))))))
1373 (when (car (setq tem (cdr tem)))
1374 (push (car tem) pre-loop-post-step-tests))
1375 (setq pre-loop-pseudo-steps
1376 (nconc pre-loop-pseudo-steps (copy-list (cadr tem))))
1377 (unless (loop-tequal (car *loop-source-code*) :and)
1378 (setq *loop-before-loop*
1379 (list* (loop-make-desetq pre-loop-pseudo-steps)
1380 (make-endtest pre-loop-post-step-tests)
1381 (loop-make-psetq pre-loop-steps)
1382 (make-endtest pre-loop-pre-step-tests)
1383 *loop-before-loop*))
1384 (setq *loop-after-body*
1385 (list* (loop-make-desetq pseudo-steps)
1386 (make-endtest post-step-tests)
1387 (loop-make-psetq steps)
1388 (make-endtest pre-step-tests)
1392 (loop-pop-source) ; Flush the "AND".
1393 (when (and (not (loop-universe-implicit-for-required *loop-universe*))
1395 (loop-lookup-keyword
1396 (car *loop-source-code*)
1397 (loop-universe-iteration-keywords *loop-universe*))))
1398 ;; The latest ANSI clarification is that the FOR/AS after the AND must
1401 (setq entry tem)))))
1403 ;;;; main iteration drivers
1405 ;;; FOR variable keyword ..args..
1406 (defun loop-do-for ()
1407 (let* ((var (loop-pop-source))
1408 (data-type (loop-optional-type var))
1409 (keyword (loop-pop-source))
1412 (setq first-arg (loop-get-form))
1413 (unless (and (symbolp keyword)
1414 (setq tem (loop-lookup-keyword
1416 (loop-universe-for-keywords *loop-universe*))))
1417 (loop-error "~S is an unknown keyword in FOR or AS clause in LOOP."
1419 (apply (car tem) var first-arg data-type (cdr tem))))
1421 (defun loop-do-repeat ()
1422 (let ((form (loop-get-form))
1423 (type (loop-check-data-type (loop-optional-type)
1424 *loop-real-data-type*)))
1425 (when (and (consp form)
1426 (eq (car form) 'the)
1427 (sb!xc:subtypep (second form) type))
1428 (setq type (second form)))
1429 (multiple-value-bind (number constantp value)
1430 (loop-constant-fold-if-possible form type)
1431 (cond ((and constantp (<= value 1)) `(t () () () ,(<= value 0) () () ()))
1432 (t (let ((var (loop-make-variable (loop-gentemp 'loop-repeat-)
1436 `((not (plusp (setq ,var (1- ,var))))
1437 () () () () () () ())
1438 `((minusp (setq ,var (1- ,var)))
1441 (defun loop-when-it-variable ()
1442 (or *loop-when-it-variable*
1443 (setq *loop-when-it-variable*
1444 (loop-make-variable (loop-gentemp 'loop-it-) nil nil))))
1446 ;;;; various FOR/AS subdispatches
1448 ;;; ANSI "FOR x = y [THEN z]" is sort of like the old Genera one when the THEN
1449 ;;; is omitted (other than being more stringent in its placement), and like the
1450 ;;; old "FOR x FIRST y THEN z" when the THEN is present. I.e., the first
1451 ;;; initialization occurs in the loop body (first-step), not in the variable
1453 (defun loop-ansi-for-equals (var val data-type)
1454 (loop-make-iteration-variable var nil data-type)
1455 (cond ((loop-tequal (car *loop-source-code*) :then)
1456 ;; Then we are the same as "FOR x FIRST y THEN z".
1458 `(() (,var ,(loop-get-form)) () ()
1459 () (,var ,val) () ()))
1460 (t ;; We are the same as "FOR x = y".
1461 `(() (,var ,val) () ()))))
1463 (defun loop-for-across (var val data-type)
1464 (loop-make-iteration-variable var nil data-type)
1465 (let ((vector-var (loop-gentemp 'loop-across-vector-))
1466 (index-var (loop-gentemp 'loop-across-index-)))
1467 (multiple-value-bind (vector-form constantp vector-value)
1468 (loop-constant-fold-if-possible val 'vector)
1470 vector-var vector-form
1471 (if (and (consp vector-form) (eq (car vector-form) 'the))
1474 (loop-make-variable index-var 0 'fixnum)
1476 (length-form (cond ((not constantp)
1477 (let ((v (loop-gentemp 'loop-across-limit-)))
1478 (push `(setq ,v (length ,vector-var))
1480 (loop-make-variable v 0 'fixnum)))
1481 (t (setq length (length vector-value)))))
1482 (first-test `(>= ,index-var ,length-form))
1483 (other-test first-test)
1484 (step `(,var (aref ,vector-var ,index-var)))
1485 (pstep `(,index-var (1+ ,index-var))))
1486 (declare (fixnum length))
1488 (setq first-test (= length 0))
1490 (setq other-test t)))
1491 `(,other-test ,step () ,pstep
1492 ,@(and (not (eq first-test other-test))
1493 `(,first-test ,step () ,pstep)))))))
1497 (defun loop-list-step (listvar)
1498 ;; We are not equipped to analyze whether 'FOO is the same as #'FOO here in
1499 ;; any sensible fashion, so let's give an obnoxious warning whenever 'FOO is
1500 ;; used as the stepping function.
1502 ;; While a Discerning Compiler may deal intelligently with
1503 ;; (FUNCALL 'FOO ...), not recognizing FOO may defeat some LOOP
1505 (let ((stepper (cond ((loop-tequal (car *loop-source-code*) :by)
1508 (t '(function cdr)))))
1509 (cond ((and (consp stepper) (eq (car stepper) 'quote))
1510 (loop-warn "Use of QUOTE around stepping function in LOOP will be left verbatim.")
1511 `(funcall ,stepper ,listvar))
1512 ((and (consp stepper) (eq (car stepper) 'function))
1513 (list (cadr stepper) listvar))
1515 `(funcall ,(loop-make-variable (loop-gentemp 'loop-fn-)
1520 (defun loop-for-on (var val data-type)
1521 (multiple-value-bind (list constantp list-value)
1522 (loop-constant-fold-if-possible val)
1523 (let ((listvar var))
1524 (cond ((and var (symbolp var))
1525 (loop-make-iteration-variable var list data-type))
1526 (t (loop-make-variable (setq listvar (loop-gentemp)) list 'list)
1527 (loop-make-iteration-variable var nil data-type)))
1528 (let ((list-step (loop-list-step listvar)))
1529 (let* ((first-endtest
1530 (hide-variable-reference
1533 ;; the following should use `atom' instead of `endp', per
1536 (other-endtest first-endtest))
1537 (when (and constantp (listp list-value))
1538 (setq first-endtest (null list-value)))
1539 (cond ((eq var listvar)
1540 ;; Contour of the loop is different because we use the user's
1542 `(() (,listvar ,(hide-variable-reference t listvar list-step))
1543 ,other-endtest () () () ,first-endtest ()))
1544 (t (let ((step `(,var ,listvar))
1545 (pseudo `(,listvar ,list-step)))
1546 `(,other-endtest ,step () ,pseudo
1547 ,@(and (not (eq first-endtest other-endtest))
1548 `(,first-endtest ,step () ,pseudo)))))))))))
1550 (defun loop-for-in (var val data-type)
1551 (multiple-value-bind (list constantp list-value)
1552 (loop-constant-fold-if-possible val)
1553 (let ((listvar (loop-gentemp 'loop-list-)))
1554 (loop-make-iteration-variable var nil data-type)
1555 (loop-make-variable listvar list 'list)
1556 (let ((list-step (loop-list-step listvar)))
1557 (let* ((first-endtest `(endp ,listvar))
1558 (other-endtest first-endtest)
1559 (step `(,var (car ,listvar)))
1560 (pseudo-step `(,listvar ,list-step)))
1561 (when (and constantp (listp list-value))
1562 (setq first-endtest (null list-value)))
1563 `(,other-endtest ,step () ,pseudo-step
1564 ,@(and (not (eq first-endtest other-endtest))
1565 `(,first-endtest ,step () ,pseudo-step))))))))
1567 ;;;; iteration paths
1569 (defstruct (loop-path
1578 (defun add-loop-path (names function universe
1579 &key preposition-groups inclusive-permitted user-data)
1580 (declare (type loop-universe universe))
1581 (unless (listp names)
1582 (setq names (list names)))
1583 (let ((ht (loop-universe-path-keywords universe))
1585 :names (mapcar #'symbol-name names)
1587 :user-data user-data
1588 :preposition-groups (mapcar (lambda (x)
1589 (if (listp x) x (list x)))
1591 :inclusive-permitted inclusive-permitted)))
1592 (dolist (name names)
1593 (setf (gethash (symbol-name name) ht) lp))
1596 ;;; Note: path functions are allowed to use loop-make-variable, hack
1597 ;;; the prologue, etc.
1598 (defun loop-for-being (var val data-type)
1599 ;; FOR var BEING each/the pathname prep-phrases using-stuff... each/the =
1600 ;; EACH or THE. Not clear if it is optional, so I guess we'll warn.
1605 (initial-prepositions nil))
1606 (cond ((loop-tmember val '(:each :the)) (setq path (loop-pop-source)))
1607 ((loop-tequal (car *loop-source-code*) :and)
1610 (unless (loop-tmember (car *loop-source-code*)
1611 '(:its :each :his :her))
1612 (loop-error "~S was found where ITS or EACH expected in LOOP iteration path syntax."
1613 (car *loop-source-code*)))
1615 (setq path (loop-pop-source))
1616 (setq initial-prepositions `((:in ,val))))
1617 (t (loop-error "unrecognizable LOOP iteration path syntax: missing EACH or THE?")))
1618 (cond ((not (symbolp path))
1620 "~S was found where a LOOP iteration path name was expected."
1622 ((not (setq data (loop-lookup-keyword path (loop-universe-path-keywords *loop-universe*))))
1623 (loop-error "~S is not the name of a LOOP iteration path." path))
1624 ((and inclusive (not (loop-path-inclusive-permitted data)))
1625 (loop-error "\"Inclusive\" iteration is not possible with the ~S LOOP iteration path." path)))
1626 (let ((fun (loop-path-function data))
1627 (preps (nconc initial-prepositions
1628 (loop-collect-prepositional-phrases
1629 (loop-path-preposition-groups data)
1631 (user-data (loop-path-user-data data)))
1632 (when (symbolp fun) (setq fun (symbol-function fun)))
1633 (setq stuff (if inclusive
1634 (apply fun var data-type preps :inclusive t user-data)
1635 (apply fun var data-type preps user-data))))
1636 (when *loop-named-variables*
1637 (loop-error "Unused USING variables: ~S." *loop-named-variables*))
1638 ;; STUFF is now (bindings prologue-forms . stuff-to-pass-back). Protect the
1639 ;; system from the user and the user from himself.
1640 (unless (member (length stuff) '(6 10))
1641 (loop-error "Value passed back by LOOP iteration path function for path ~S has invalid length."
1643 (do ((l (car stuff) (cdr l)) (x)) ((null l))
1644 (if (atom (setq x (car l)))
1645 (loop-make-iteration-variable x nil nil)
1646 (loop-make-iteration-variable (car x) (cadr x) (caddr x))))
1647 (setq *loop-prologue* (nconc (reverse (cadr stuff)) *loop-prologue*))
1650 (defun named-variable (name)
1651 (let ((tem (loop-tassoc name *loop-named-variables*)))
1652 (declare (list tem))
1653 (cond ((null tem) (values (loop-gentemp) nil))
1654 (t (setq *loop-named-variables* (delete tem *loop-named-variables*))
1655 (values (cdr tem) t)))))
1657 (defun loop-collect-prepositional-phrases (preposition-groups
1661 (flet ((in-group-p (x group) (car (loop-tmember x group))))
1663 (prepositional-phrases initial-phrases)
1664 (this-group nil nil)
1666 (disallowed-prepositions
1667 (mapcan #'(lambda (x)
1669 (find (car x) preposition-groups :test #'in-group-p)))
1671 (used-prepositions (mapcar #'car initial-phrases)))
1672 ((null *loop-source-code*) (nreverse prepositional-phrases))
1673 (declare (symbol this-prep))
1674 (setq token (car *loop-source-code*))
1675 (dolist (group preposition-groups)
1676 (when (setq this-prep (in-group-p token group))
1677 (return (setq this-group group))))
1679 (when (member this-prep disallowed-prepositions)
1681 (if (member this-prep used-prepositions)
1682 "A ~S prepositional phrase occurs multiply for some LOOP clause."
1683 "Preposition ~S was used when some other preposition has subsumed it.")
1685 (setq used-prepositions (if (listp this-group)
1686 (append this-group used-prepositions)
1687 (cons this-group used-prepositions)))
1689 (push (list this-prep (loop-get-form)) prepositional-phrases))
1690 ((and USING-allowed (loop-tequal token 'using))
1692 (do ((z (loop-pop-source) (loop-pop-source)) (tem)) (nil)
1695 (not (null (cddr z)))
1696 (not (symbolp (car z)))
1697 (and (cadr z) (not (symbolp (cadr z)))))
1698 (loop-error "~S bad variable pair in path USING phrase" z))
1700 (if (setq tem (loop-tassoc (car z) *loop-named-variables*))
1702 "The variable substitution for ~S occurs twice in a USING phrase,~@
1704 (car z) (cadr z) (cadr tem))
1705 (push (cons (car z) (cadr z)) *loop-named-variables*)))
1706 (when (or (null *loop-source-code*)
1707 (symbolp (car *loop-source-code*)))
1709 (t (return (nreverse prepositional-phrases)))))))
1711 ;;;; master sequencer function
1713 (defun loop-sequencer (indexv indexv-type indexv-user-specified-p
1714 variable variable-type
1715 sequence-variable sequence-type
1716 step-hack default-top
1718 (let ((endform nil) ; Form (constant or variable) with limit value
1719 (sequencep nil) ; T if sequence arg has been provided
1720 (testfn nil) ; endtest function
1721 (test nil) ; endtest form
1722 (stepby (1+ (or (loop-typed-init indexv-type) 0))) ; our increment
1723 (stepby-constantp t)
1724 (step nil) ; step form
1725 (dir nil) ; direction of stepping: NIL, :UP, :DOWN
1726 (inclusive-iteration nil) ; T if include last index
1727 (start-given nil) ; T when prep phrase has specified start
1729 (start-constantp nil)
1730 (limit-given nil) ; T when prep phrase has specified end
1731 (limit-constantp nil)
1734 (when variable (loop-make-iteration-variable variable nil variable-type))
1735 (do ((l prep-phrases (cdr l)) (prep) (form) (odir)) ((null l))
1736 (setq prep (caar l) form (cadar l))
1740 (loop-make-variable sequence-variable form sequence-type))
1741 ((:from :downfrom :upfrom)
1742 (setq start-given t)
1743 (cond ((eq prep :downfrom) (setq dir ':down))
1744 ((eq prep :upfrom) (setq dir ':up)))
1745 (multiple-value-setq (form start-constantp start-value)
1746 (loop-constant-fold-if-possible form indexv-type))
1747 (loop-make-iteration-variable indexv form indexv-type))
1748 ((:upto :to :downto :above :below)
1749 (cond ((loop-tequal prep :upto) (setq inclusive-iteration
1751 ((loop-tequal prep :to) (setq inclusive-iteration t))
1752 ((loop-tequal prep :downto) (setq inclusive-iteration
1754 ((loop-tequal prep :above) (setq dir ':down))
1755 ((loop-tequal prep :below) (setq dir ':up)))
1756 (setq limit-given t)
1757 (multiple-value-setq (form limit-constantp limit-value)
1758 (loop-constant-fold-if-possible form indexv-type))
1759 (setq endform (if limit-constantp
1762 (loop-gentemp 'loop-limit-) form indexv-type))))
1764 (multiple-value-setq (form stepby-constantp stepby)
1765 (loop-constant-fold-if-possible form indexv-type))
1766 (unless stepby-constantp
1767 (loop-make-variable (setq stepby (loop-gentemp 'loop-step-by-))
1771 "~S invalid preposition in sequencing or sequence path;~@
1772 maybe invalid prepositions were specified in iteration path descriptor?"
1774 (when (and odir dir (not (eq dir odir)))
1775 (loop-error "conflicting stepping directions in LOOP sequencing path"))
1777 (when (and sequence-variable (not sequencep))
1778 (loop-error "missing OF or IN phrase in sequence path"))
1779 ;; Now fill in the defaults.
1781 (loop-make-iteration-variable
1783 (setq start-constantp t
1784 start-value (or (loop-typed-init indexv-type) 0))
1786 (cond ((member dir '(nil :up))
1787 (when (or limit-given default-top)
1789 (loop-make-variable (setq endform
1790 (loop-gentemp 'loop-seq-limit-))
1792 (push `(setq ,endform ,default-top) *loop-prologue*))
1793 (setq testfn (if inclusive-iteration '> '>=)))
1794 (setq step (if (eql stepby 1) `(1+ ,indexv) `(+ ,indexv ,stepby))))
1795 (t (unless start-given
1797 (loop-error "don't know where to start stepping"))
1798 (push `(setq ,indexv (1- ,default-top)) *loop-prologue*))
1799 (when (and default-top (not endform))
1800 (setq endform (loop-typed-init indexv-type)
1801 inclusive-iteration t))
1802 (when endform (setq testfn (if inclusive-iteration '< '<=)))
1804 (if (eql stepby 1) `(1- ,indexv) `(- ,indexv ,stepby)))))
1807 (hide-variable-reference t indexv `(,testfn ,indexv ,endform))))
1810 `(,variable ,(hide-variable-reference indexv-user-specified-p
1813 (let ((first-test test) (remaining-tests test))
1814 (when (and stepby-constantp start-constantp limit-constantp)
1815 (when (setq first-test
1816 (funcall (symbol-function testfn)
1819 (setq remaining-tests t)))
1820 `(() (,indexv ,(hide-variable-reference t indexv step))
1821 ,remaining-tests ,step-hack () () ,first-test ,step-hack))))
1823 ;;;; interfaces to the master sequencer
1825 (defun loop-for-arithmetic (var val data-type kwd)
1827 var (loop-check-data-type data-type *loop-real-data-type*) t
1828 nil nil nil nil nil nil
1829 (loop-collect-prepositional-phrases
1830 '((:from :upfrom :downfrom) (:to :upto :downto :above :below) (:by))
1831 nil (list (list kwd val)))))
1833 (defun loop-sequence-elements-path (variable data-type prep-phrases
1839 (multiple-value-bind (indexv indexv-user-specified-p) (named-variable 'index)
1840 (let ((sequencev (named-variable 'sequence)))
1841 (list* nil nil ; dummy bindings and prologue
1843 indexv 'fixnum indexv-user-specified-p
1844 variable (or data-type element-type)
1845 sequencev sequence-type
1846 `(,fetch-function ,sequencev ,indexv)
1847 `(,size-function ,sequencev)
1850 ;;;; builtin LOOP iteration paths
1853 (loop for v being the hash-values of ht do (print v))
1854 (loop for k being the hash-keys of ht do (print k))
1855 (loop for v being the hash-values of ht using (hash-key k) do (print (list k v)))
1856 (loop for k being the hash-keys of ht using (hash-value v) do (print (list k v)))
1859 (defun loop-hash-table-iteration-path (variable data-type prep-phrases
1860 &key (which (required-argument)))
1861 (declare (type (member :hash-key :hash-value) which))
1862 (cond ((or (cdr prep-phrases) (not (member (caar prep-phrases) '(:in :of))))
1863 (loop-error "too many prepositions!"))
1864 ((null prep-phrases)
1865 (loop-error "missing OF or IN in ~S iteration path")))
1866 (let ((ht-var (loop-gentemp 'loop-hashtab-))
1867 (next-fn (loop-gentemp 'loop-hashtab-next-))
1868 (dummy-predicate-var nil)
1870 (multiple-value-bind (other-var other-p)
1871 (named-variable (if (eq which 'hash-key) 'hash-value 'hash-key))
1872 ;; @@@@ named-variable returns a second value of T if the name was
1873 ;; actually specified, so clever code can throw away the gensym'ed up
1874 ;; variable if it isn't really needed. The following is for those
1875 ;; implementations in which we cannot put dummy NILs into
1876 ;; multiple-value-setq variable lists.
1878 dummy-predicate-var (loop-when-it-variable))
1881 (bindings `((,variable nil ,data-type)
1882 (,ht-var ,(cadar prep-phrases))
1883 ,@(and other-p other-var `((,other-var nil))))))
1884 (if (eq which 'hash-key)
1885 (setq key-var variable val-var (and other-p other-var))
1886 (setq key-var (and other-p other-var) val-var variable))
1887 (push `(with-hash-table-iterator (,next-fn ,ht-var)) *loop-wrappers*)
1888 (when (consp key-var)
1890 `(,key-var ,(setq key-var (loop-gentemp 'loop-hash-key-temp-))
1892 (push `(,key-var nil) bindings))
1893 (when (consp val-var)
1895 `(,val-var ,(setq val-var (loop-gentemp 'loop-hash-val-temp-))
1897 (push `(,val-var nil) bindings))
1898 `(,bindings ;bindings
1902 (not (multiple-value-setq (,dummy-predicate-var ,key-var ,val-var)
1903 (,next-fn))) ;post-test
1906 (defun loop-package-symbols-iteration-path (variable data-type prep-phrases
1908 (cond ((or (cdr prep-phrases) (not (member (caar prep-phrases) '(:in :of))))
1909 (loop-error "Too many prepositions!"))
1910 ((null prep-phrases)
1911 (loop-error "missing OF or IN in ~S iteration path")))
1912 (unless (symbolp variable)
1913 (loop-error "Destructuring is not valid for package symbol iteration."))
1914 (let ((pkg-var (loop-gentemp 'loop-pkgsym-))
1915 (next-fn (loop-gentemp 'loop-pkgsym-next-)))
1916 (push `(with-package-iterator (,next-fn ,pkg-var ,@symbol-types))
1918 `(((,variable nil ,data-type) (,pkg-var ,(cadar prep-phrases)))
1922 (not (multiple-value-setq (,(loop-when-it-variable)
1929 (defun make-ansi-loop-universe (extended-p)
1930 (let ((w (make-standard-loop-universe
1931 :keywords `((named (loop-do-named))
1932 (initially (loop-do-initially))
1933 (finally (loop-do-finally))
1935 (doing (loop-do-do))
1936 (return (loop-do-return))
1937 (collect (loop-list-collection list))
1938 (collecting (loop-list-collection list))
1939 (append (loop-list-collection append))
1940 (appending (loop-list-collection append))
1941 (nconc (loop-list-collection nconc))
1942 (nconcing (loop-list-collection nconc))
1943 (count (loop-sum-collection count
1944 ,*loop-real-data-type*
1946 (counting (loop-sum-collection count
1947 ,*loop-real-data-type*
1949 (sum (loop-sum-collection sum number number))
1950 (summing (loop-sum-collection sum number number))
1951 (maximize (loop-maxmin-collection max))
1952 (minimize (loop-maxmin-collection min))
1953 (maximizing (loop-maxmin-collection max))
1954 (minimizing (loop-maxmin-collection min))
1955 (always (loop-do-always t nil)) ; Normal, do always
1956 (never (loop-do-always t t)) ; Negate test on always.
1957 (thereis (loop-do-thereis t))
1958 (while (loop-do-while nil :while)) ; Normal, do while
1959 (until (loop-do-while t :until)) ;Negate test on while
1960 (when (loop-do-if when nil)) ; Normal, do when
1961 (if (loop-do-if if nil)) ; synonymous
1962 (unless (loop-do-if unless t)) ; Negate test on when
1963 (with (loop-do-with)))
1964 :for-keywords '((= (loop-ansi-for-equals))
1965 (across (loop-for-across))
1968 (from (loop-for-arithmetic :from))
1969 (downfrom (loop-for-arithmetic :downfrom))
1970 (upfrom (loop-for-arithmetic :upfrom))
1971 (below (loop-for-arithmetic :below))
1972 (to (loop-for-arithmetic :to))
1973 (upto (loop-for-arithmetic :upto))
1974 (being (loop-for-being)))
1975 :iteration-keywords '((for (loop-do-for))
1977 (repeat (loop-do-repeat)))
1978 :type-symbols '(array atom bignum bit bit-vector character
1979 compiled-function complex cons double-float
1980 fixnum float function hash-table integer
1981 keyword list long-float nil null number
1982 package pathname random-state ratio rational
1983 readtable sequence short-float simple-array
1984 simple-bit-vector simple-string simple-vector
1985 single-float standard-char stream string
1986 base-char symbol t vector)
1988 :ansi (if extended-p :extended t))))
1989 (add-loop-path '(hash-key hash-keys) 'loop-hash-table-iteration-path w
1990 :preposition-groups '((:of :in))
1991 :inclusive-permitted nil
1992 :user-data '(:which :hash-key))
1993 (add-loop-path '(hash-value hash-values) 'loop-hash-table-iteration-path w
1994 :preposition-groups '((:of :in))
1995 :inclusive-permitted nil
1996 :user-data '(:which :hash-value))
1997 (add-loop-path '(symbol symbols) 'loop-package-symbols-iteration-path w
1998 :preposition-groups '((:of :in))
1999 :inclusive-permitted nil
2000 :user-data '(:symbol-types (:internal
2003 (add-loop-path '(external-symbol external-symbols)
2004 'loop-package-symbols-iteration-path w
2005 :preposition-groups '((:of :in))
2006 :inclusive-permitted nil
2007 :user-data '(:symbol-types (:external)))
2008 (add-loop-path '(present-symbol present-symbols)
2009 'loop-package-symbols-iteration-path w
2010 :preposition-groups '((:of :in))
2011 :inclusive-permitted nil
2012 :user-data '(:symbol-types (:internal)))
2015 (defparameter *loop-ansi-universe*
2016 (make-ansi-loop-universe nil))
2018 (defun loop-standard-expansion (keywords-and-forms environment universe)
2019 (if (and keywords-and-forms (symbolp (car keywords-and-forms)))
2020 (loop-translate keywords-and-forms environment universe)
2021 (let ((tag (gensym)))
2022 `(block nil (tagbody ,tag (progn ,@keywords-and-forms) (go ,tag))))))
2024 (sb!int:defmacro-mundanely loop (&environment env &rest keywords-and-forms)
2025 (loop-standard-expansion keywords-and-forms env *loop-ansi-universe*))
2027 (sb!int:defmacro-mundanely loop-finish ()
2029 "Cause the iteration to terminate \"normally\", the same as implicit
2030 termination by an iteration driving clause, or by use of WHILE or
2031 UNTIL -- the epilogue code (if any) will be run, and any implicitly
2032 collected result will be returned as the value of the LOOP."