diff options
Diffstat (limited to 'sql/ansi-loop.lisp')
| -rw-r--r-- | sql/ansi-loop.lisp | 2282 |
1 files changed, 2282 insertions, 0 deletions
diff --git a/sql/ansi-loop.lisp b/sql/ansi-loop.lisp new file mode 100644 index 0000000..6a2cab4 --- /dev/null +++ b/sql/ansi-loop.lisp @@ -0,0 +1,2282 @@ +;;; -*- Mode: LISP; Package: ANSI-LOOP; Syntax: Common-lisp; Base: 10; Lowercase:T -*- +;;; +;;; This file is included with CLSQL to be used by CLISP which does not +;;; have an extensible LOOP macro. It was copied from the CMUCL 19c source. +;;; Minor porting changes have been made Copyright (c) 2006 Kevin M. Rosenberg +;;; +;;;> +;;;> Portions of LOOP are Copyright (c) 1986 by the Massachusetts Institute of Technology. +;;;> All Rights Reserved. +;;;> +;;;> Permission to use, copy, modify and distribute this software and its +;;;> documentation for any purpose and without fee is hereby granted, +;;;> provided that the M.I.T. copyright notice appear in all copies and that +;;;> both that copyright notice and this permission notice appear in +;;;> supporting documentation. The names "M.I.T." and "Massachusetts +;;;> Institute of Technology" may not be used in advertising or publicity +;;;> pertaining to distribution of the software without specific, written +;;;> prior permission. Notice must be given in supporting documentation that +;;;> copying distribution is by permission of M.I.T. M.I.T. makes no +;;;> representations about the suitability of this software for any purpose. +;;;> It is provided "as is" without express or implied warranty. +;;;> +;;;> Massachusetts Institute of Technology +;;;> 77 Massachusetts Avenue +;;;> Cambridge, Massachusetts 02139 +;;;> United States of America +;;;> +1-617-253-1000 +;;;> +;;;> Portions of LOOP are Copyright (c) 1989, 1990, 1991, 1992 by Symbolics, Inc. +;;;> All Rights Reserved. +;;;> +;;;> Permission to use, copy, modify and distribute this software and its +;;;> documentation for any purpose and without fee is hereby granted, +;;;> provided that the Symbolics copyright notice appear in all copies and +;;;> that both that copyright notice and this permission notice appear in +;;;> supporting documentation. The name "Symbolics" may not be used in +;;;> advertising or publicity pertaining to distribution of the software +;;;> without specific, written prior permission. Notice must be given in +;;;> supporting documentation that copying distribution is by permission of +;;;> Symbolics. Symbolics makes no representations about the suitability of +;;;> this software for any purpose. It is provided "as is" without express +;;;> or implied warranty. +;;;> +;;;> Symbolics, CLOE Runtime, and Minima are trademarks, and CLOE, Genera, +;;;> and Zetalisp are registered trademarks of Symbolics, Inc. +;;;> +;;;> Symbolics, Inc. +;;;> 8 New England Executive Park, East +;;;> Burlington, Massachusetts 01803 +;;;> United States of America +;;;> +1-617-221-1000 + +;; $aclHeader: loop.cl,v 1.5 91/12/04 01:13:48 cox acl4_1 $ +#+cmu +(ext:file-comment + "$Header: /project/cmucl/cvsroot/src/code/loop.lisp,v 1.27 2004/10/21 02:31:08 rtoy Exp $") + + +;;;; LOOP Iteration Macro + +#+clisp +(eval-when (:compile-toplevel :load-toplevel :execute) + (setf (ext:package-lock (find-package "COMMON-LISP")) nil)) +(defpackage ansi-loop (:use :common-lisp) + (:shadowing-import-from "COMMON-LISP" "LOOP" "LOOP-FINISH")) +(in-package ansi-loop) + +;;; Technology. +;;; +;;; The LOOP iteration macro is one of a number of pieces of code +;;; originally developed at MIT and licensed as set out above. This +;;; version of LOOP, which is almost entirely rewritten both as a +;;; clean-up and to conform with the ANSI Lisp LOOP standard, started +;;; life as MIT LOOP version 829 (which was a part of NIL, possibly +;;; never released). +;;; +;;; A "light revision" was performed by Glenn Burke while at Palladian +;;; Software in April 1986, to make the code run in Common Lisp. This +;;; revision was informally distributed to a number of people, and was +;;; sort of the "MIT" version of LOOP for running in Common Lisp. +;;; +;;; A later more drastic revision was performed at Palladian perhaps a +;;; year later. This version was more thoroughly Common Lisp in +;;; style, with a few miscellaneous internal improvements and +;;; extensions. Glenn Burke lost track of this source, apparently +;;; never having moved it to the MIT distribution point; and does not +;;; remember if it was ever distributed. +;;; +;;; This revision for the ANSI standard is based on the code of Glenn +;;; Burke's April 1986 version, with almost everything redesigned +;;; and/or rewritten. + + +;;; The design of this LOOP is intended to permit, using mostly the same +;;; kernel of code, up to three different "loop" macros: +;;; +;;; (1) The unextended, unextensible ANSI standard LOOP; +;;; +;;; (2) A clean "superset" extension of the ANSI LOOP which provides +;;; functionality similar to that of the old LOOP, but "in the style of" +;;; the ANSI LOOP. For instance, user-definable iteration paths, with a +;;; somewhat cleaned-up interface. +;;; +;;; (3) Extensions provided in another file which can make this LOOP +;;; kernel behave largely compatibly with the Genera-vintage LOOP macro, +;;; with only a small addition of code (instead of two whole, separate, +;;; LOOP macros). +;;; +;;; Each of the above three LOOP variations can coexist in the same LISP +;;; environment. +;;; + + +;;;; Miscellaneous Environment Things + + + +;;;@@@@The LOOP-Prefer-POP feature makes LOOP generate code which "prefers" to use POP or +;;; its obvious expansion (prog1 (car x) (setq x (cdr x))). Usually this involves +;;; shifting fenceposts in an iteration or series of carcdr operations. This is +;;; primarily recognized in the list iterators (FOR .. {IN,ON}), and LOOP's +;;; destructuring setq code. +(eval-when (compile load eval) + #+(or Genera Minima) (pushnew :LOOP-Prefer-POP *features*) + ) + + +;;; The uses of this macro are retained in the CL version of loop, in +;;; case they are needed in a particular implementation. Originally +;;; dating from the use of the Zetalisp COPYLIST* function, this is used +;;; in situations where, were cdr-coding in use, having cdr-NIL at the +;;; end of the list might be suboptimal because the end of the list will +;;; probably be RPLACDed and so cdr-normal should be used instead. +(defmacro loop-copylist* (l) + #+Genera `(lisp:copy-list ,l nil t) ; arglist = (list &optional area force-dotted) + ;;@@@@Explorer?? + #-Genera `(copy-list ,l) + ) + + +(defvar *loop-gentemp* t) + +(defun loop-gentemp (&optional (pref 'loopvar-)) + (if *loop-gentemp* + (gensym (string pref)) + (gensym))) + + + +(eval-when (:compile-toplevel :load-toplevel :execute) + (defvar *loop-real-data-type* 'real)) + + +(defun loop-optimization-quantities (env) + ;;@@@@ The ANSI conditionalization here is for those lisps that implement + ;; DECLARATION-INFORMATION (from cleanup SYNTACTIC-ENVIRONMENT-ACCESS). + ;; It is really commentary on how this code could be written. I don't + ;; actually expect there to be an ANSI #+-conditional -- it should be + ;; replaced with the appropriate conditional name for your + ;; implementation/dialect. + (declare #-ANSI (ignore env) + #+Genera (values speed space safety compilation-speed debug)) + #+ANSI (let ((stuff (declaration-information 'optimize env))) + (values (or (cdr (assoc 'speed stuff)) 1) + (or (cdr (assoc 'space stuff)) 1) + (or (cdr (assoc 'safety stuff)) 1) + (or (cdr (assoc 'compilation-speed stuff)) 1) + (or (cdr (assoc 'debug stuff)) 1))) + #+CLOE-Runtime (values compiler::time compiler::space + compiler::safety compiler::compilation-speed 1) + #-(or ANSI CLOE-Runtime) (values 1 1 1 1 1)) + + +;;;@@@@ The following form takes a list of variables and a form which presumably +;;; references those variables, and wraps it somehow so that the compiler does not +;;; consider those variables have been referenced. The intent of this is that +;;; iteration variables can be flagged as unused by the compiler, e.g. I in +;;; (loop for i from 1 to 10 do (print t)), since we will tell it when a usage +;;; of it is "invisible" or "not to be considered". +;;;We implicitly assume that a setq does not count as a reference. That is, the +;;; kind of form generated for the above loop construct to step I, simplified, is +;;; `(SETQ I ,(HIDE-VARIABLE-REFERENCES '(I) '(1+ I))). +(defun hide-variable-references (variable-list form) + (declare #-Genera (ignore variable-list)) + #+Genera (if variable-list `(compiler:invisible-references ,variable-list ,form) form) + #-Genera form) + + +;;;@@@@ The following function takes a flag, a variable, and a form which presumably +;;; references that variable, and wraps it somehow so that the compiler does not +;;; consider that variable to have been referenced. The intent of this is that +;;; iteration variables can be flagged as unused by the compiler, e.g. I in +;;; (loop for i from 1 to 10 do (print t)), since we will tell it when a usage +;;; of it is "invisible" or "not to be considered". +;;;We implicitly assume that a setq does not count as a reference. That is, the +;;; kind of form generated for the above loop construct to step I, simplified, is +;;; `(SETQ I ,(HIDE-VARIABLE-REFERENCES T 'I '(1+ I))). +;;;Certain cases require that the "invisibility" of the reference be conditional upon +;;; something. This occurs in cases of "named" variables (the USING clause). For instance, +;;; we want IDX in (LOOP FOR E BEING THE VECTOR-ELEMENTS OF V USING (INDEX IDX) ...) +;;; to be "invisible" when it is stepped, so that the user gets informed if IDX is +;;; not referenced. However, if no USING clause is present, we definitely do not +;;; want to be informed that some random gensym is not used. +;;;It is easier for the caller to do this conditionally by passing a flag (which +;;; happens to be the second value of NAMED-VARIABLE, q.v.) to this function than +;;; for all callers to contain the conditional invisibility construction. +(defun hide-variable-reference (really-hide variable form) + (declare #-Genera (ignore really-hide variable)) + #+Genera (if (and really-hide variable (atom variable)) ;Punt on destructuring patterns + `(compiler:invisible-references (,variable) ,form) + form) + #-Genera form) + + +;;;; List Collection Macrology + + +(defmacro with-loop-list-collection-head ((head-var tail-var &optional user-head-var) + &body body) + ;;@@@@ TI? Exploder? + #+LISPM (let ((head-place (or user-head-var head-var))) + `(let* ((,head-place nil) + (,tail-var + ,(hide-variable-reference + user-head-var user-head-var + `(progn #+Genera (scl:locf ,head-place) + #-Genera (system:variable-location ,head-place))))) + ,@body)) + #-LISPM (let ((l (and user-head-var (list (list user-head-var nil))))) + #+CLOE `(sys::with-stack-list* (,head-var nil nil) + (let ((,tail-var ,head-var) ,@l) + ,@body)) + #-CLOE `(let* ((,head-var (list nil)) (,tail-var ,head-var) ,@l) + ,@body))) + + +(defmacro loop-collect-rplacd (&environment env + (head-var tail-var &optional user-head-var) form) + (declare + #+LISPM (ignore head-var user-head-var) ;use locatives, unconditionally update through the tail. + ) + (setq form (macroexpand form env)) + (flet ((cdr-wrap (form n) + (declare (fixnum n)) + (do () ((<= n 4) (setq form `(,(case n + (1 'cdr) + (2 'cddr) + (3 'cdddr) + (4 'cddddr)) + ,form))) + (setq form `(cddddr ,form) n (- n 4))))) + (let ((tail-form form) (ncdrs nil)) + ;;Determine if the form being constructed is a list of known length. + (when (consp form) + (cond ((eq (car form) 'list) + (setq ncdrs (1- (length (cdr form)))) + ;;@@@@ Because the last element is going to be RPLACDed, + ;; we don't want the cdr-coded implementations to use + ;; cdr-nil at the end (which would just force copying + ;; the whole list again). + #+LISPM (setq tail-form `(list* ,@(cdr form) nil))) + ((member (car form) '(list* cons)) + (when (and (cddr form) (member (car (last form)) '(nil 'nil))) + (setq ncdrs (- (length (cdr form)) 2)))))) + (let ((answer + (cond ((null ncdrs) + `(when (setf (cdr ,tail-var) ,tail-form) + (setq ,tail-var (last (cdr ,tail-var))))) + ((< ncdrs 0) (return-from loop-collect-rplacd nil)) + ((= ncdrs 0) + ;;@@@@ Here we have a choice of two idioms: + ;; (rplacd tail (setq tail tail-form)) + ;; (setq tail (setf (cdr tail) tail-form)). + ;;Genera and most others I have seen do better with the former. + `(rplacd ,tail-var (setq ,tail-var ,tail-form))) + (t `(setq ,tail-var ,(cdr-wrap `(setf (cdr ,tail-var) ,tail-form) + ncdrs)))))) + ;;If not using locatives or something similar to update the user's + ;; head variable, we've got to set it... It's harmless to repeatedly set it + ;; unconditionally, and probably faster than checking. + #-LISPM (when user-head-var + (setq answer `(progn ,answer (setq ,user-head-var (cdr ,head-var))))) + answer)))) + + +(defmacro loop-collect-answer (head-var &optional user-head-var) + (or user-head-var + (progn + ;;If we use locatives to get tail-updating to update the head var, + ;; then the head var itself contains the answer. Otherwise we + ;; have to cdr it. + #+LISPM head-var + #-LISPM `(cdr ,head-var)))) + + +;;;; Maximization Technology + + +#| +The basic idea of all this minimax randomness here is that we have to +have constructed all uses of maximize and minimize to a particular +"destination" before we can decide how to code them. The goal is to not +have to have any kinds of flags, by knowing both that (1) the type is +something which we can provide an initial minimum or maximum value for +and (2) know that a MAXIMIZE and MINIMIZE are not being combined. + +SO, we have a datastructure which we annotate with all sorts of things, +incrementally updating it as we generate loop body code, and then use +a wrapper and internal macros to do the coding when the loop has been +constructed. +|# + + +(defstruct (loop-minimax + (:constructor make-loop-minimax-internal) + (:copier nil) + (:predicate nil)) + answer-variable + type + temp-variable + flag-variable + operations + infinity-data) + + +(defvar *loop-minimax-type-infinities-alist* + ;;@@@@ This is the sort of value this should take on for a Lisp that has + ;; "eminently usable" infinities. n.b. there are neither constants nor + ;; printed representations for infinities defined by CL. + ;;@@@@ This grotesque read-from-string below is to help implementations + ;; which croak on the infinity character when it appears in a token, even + ;; conditionalized out. + #+Genera + '#.(read-from-string + "((fixnum most-positive-fixnum most-negative-fixnum) + (short-float +1s -1s) + (single-float +1f -1f) + (double-float +1d -1d) + (long-float +1l -1l))") + ;;This is how the alist should look for a lisp that has no infinities. In + ;; that case, MOST-POSITIVE-x-FLOAT really IS the most positive. + #+(or CLOE-Runtime Minima) + '((fixnum most-positive-fixnum most-negative-fixnum) + (short-float most-positive-short-float most-negative-short-float) + (single-float most-positive-single-float most-negative-single-float) + (double-float most-positive-double-float most-negative-double-float) + (long-float most-positive-long-float most-negative-long-float)) + ;; CMUCL has infinities so let's use them. + #+CMU + '((fixnum most-positive-fixnum most-negative-fixnum) + (short-float ext:single-float-positive-infinity ext:single-float-negative-infinity) + (single-float ext:single-float-positive-infinity ext:single-float-negative-infinity) + (double-float ext:double-float-positive-infinity ext:double-float-negative-infinity) + (long-float ext:long-float-positive-infinity ext:long-float-negative-infinity)) + ;; If we don't know, then we cannot provide "infinite" initial values for any of the + ;; types but FIXNUM: + #-(or Genera CLOE-Runtime Minima CMU) + '((fixnum most-positive-fixnum most-negative-fixnum)) + ) + + +(defun make-loop-minimax (answer-variable type) + (let ((infinity-data (cdr (assoc type *loop-minimax-type-infinities-alist* :test #'subtypep)))) + (make-loop-minimax-internal + :answer-variable answer-variable + :type type + :temp-variable (loop-gentemp 'loop-maxmin-temp-) + :flag-variable (and (not infinity-data) (loop-gentemp 'loop-maxmin-flag-)) + :operations nil + :infinity-data infinity-data))) + + +(defun loop-note-minimax-operation (operation minimax) + (pushnew (the symbol operation) (loop-minimax-operations minimax)) + (when (and (cdr (loop-minimax-operations minimax)) + (not (loop-minimax-flag-variable minimax))) + (setf (loop-minimax-flag-variable minimax) (loop-gentemp 'loop-maxmin-flag-))) + operation) + + +(defmacro with-minimax-value (lm &body body) + (let ((init (loop-typed-init (loop-minimax-type lm))) + (which (car (loop-minimax-operations lm))) + (infinity-data (loop-minimax-infinity-data lm)) + (answer-var (loop-minimax-answer-variable lm)) + (temp-var (loop-minimax-temp-variable lm)) + (flag-var (loop-minimax-flag-variable lm)) + (type (loop-minimax-type lm))) + (if flag-var + `(let ((,answer-var ,init) (,temp-var ,init) (,flag-var nil)) + (declare (type ,type ,answer-var ,temp-var)) + ,@body) + `(let ((,answer-var ,(if (eq which 'min) (first infinity-data) (second infinity-data))) + (,temp-var ,init)) + (declare (type ,type ,answer-var ,temp-var)) + ,@body)))) + + +(defmacro loop-accumulate-minimax-value (lm operation form) + (let* ((answer-var (loop-minimax-answer-variable lm)) + (temp-var (loop-minimax-temp-variable lm)) + (flag-var (loop-minimax-flag-variable lm)) + (test + (hide-variable-reference + t (loop-minimax-answer-variable lm) + `(,(ecase operation + (min '<) + (max '>)) + ,temp-var ,answer-var)))) + `(progn + (setq ,temp-var ,form) + (when ,(if flag-var `(or (not ,flag-var) ,test) test) + (setq ,@(and flag-var `(,flag-var t)) + ,answer-var ,temp-var))))) + + + +;;;; Loop Keyword Tables + + +#| +LOOP keyword tables are hash tables string keys and a test of EQUAL. + +The actual descriptive/dispatch structure used by LOOP is called a "loop +universe" contains a few tables and parameterizations. The basic idea is +that we can provide a non-extensible ANSI-compatible loop environment, +an extensible ANSI-superset loop environment, and (for such environments +as CLOE) one which is "sufficiently close" to the old Genera-vintage +LOOP for use by old user programs without requiring all of the old LOOP +code to be loaded. +|# + + +;;;; Token Hackery + + +;;;Compare two "tokens". The first is the frob out of *LOOP-SOURCE-CODE*, +;;; the second a symbol to check against. +(defun loop-tequal (x1 x2) + (and (symbolp x1) (string= x1 x2))) + + +(defun loop-tassoc (kwd alist) + (and (symbolp kwd) (assoc kwd alist :test #'string=))) + + +(defun loop-tmember (kwd list) + (and (symbolp kwd) (member kwd list :test #'string=))) + + +(defun loop-lookup-keyword (loop-token table) + (and (symbolp loop-token) + (values (gethash (symbol-name loop-token) table)))) + + +(defmacro loop-store-table-data (symbol table datum) + `(setf (gethash (symbol-name ,symbol) ,table) ,datum)) + + +(defstruct (loop-universe + (:print-function print-loop-universe) + (:copier nil) + (:predicate nil)) + keywords ;hash table, value = (fn-name . extra-data). + iteration-keywords ;hash table, value = (fn-name . extra-data). + for-keywords ;hash table, value = (fn-name . extra-data). + path-keywords ;hash table, value = (fn-name . extra-data). + type-symbols ;hash table of type SYMBOLS, test EQ, value = CL type specifier. + type-keywords ;hash table of type STRINGS, test EQUAL, value = CL type spec. + ansi ;NIL, T, or :EXTENDED. + implicit-for-required ;see loop-hack-iteration + ) + + +(eval-when (:compile-toplevel :load-toplevel :execute) + (defun print-loop-universe (u stream level) + (declare (ignore level)) + (let ((str (case (loop-universe-ansi u) + ((nil) "Non-ANSI") + ((t) "ANSI") + (:extended "Extended-ANSI") + (t (loop-universe-ansi u))))) + ;;Cloe could be done with the above except for bootstrap lossage... + #+CLOE + (format stream "#<~S ~A ~X>" (type-of u) str (sys::address-of u)) + (print-unreadable-object (u stream :type t :identity t) + (princ str stream)) + ))) + + +;;;This is the "current" loop context in use when we are expanding a +;;;loop. It gets bound on each invocation of LOOP. +(defvar *loop-universe*) + + +(eval-when (:compile-toplevel :load-toplevel :execute) + (defun make-standard-loop-universe (&key keywords for-keywords iteration-keywords path-keywords + type-keywords type-symbols ansi) + #-(and CLOE Source-Bootstrap) (check-type ansi (member nil t :extended)) + (flet ((maketable (entries) + (let* ((size (length entries)) + (ht (make-hash-table :size (if (< size 10) 10 size) :test #'equal))) + (dolist (x entries) (setf (gethash (symbol-name (car x)) ht) (cadr x))) + ht))) + (make-loop-universe + :keywords (maketable keywords) + :for-keywords (maketable for-keywords) + :iteration-keywords (maketable iteration-keywords) + :path-keywords (maketable path-keywords) + :ansi ansi + :implicit-for-required (not (null ansi)) + :type-keywords (maketable type-keywords) + :type-symbols (let* ((size (length type-symbols)) + (ht (make-hash-table :size (if (< size 10) 10 size) :test #'eq))) + (dolist (x type-symbols) + (if (atom x) (setf (gethash x ht) x) (setf (gethash (car x) ht) (cadr x)))) + ht))))) + + + +;;;; Setq Hackery + + +(defvar *loop-destructuring-hooks* + nil + "If not NIL, this must be a list of two things: +a LET-like macro, and a SETQ-like macro, which perform LOOP-style destructuring.") + + +(defun loop-make-psetq (frobs) + (and frobs + (loop-make-desetq + (list (car frobs) + (if (null (cddr frobs)) (cadr frobs) + `(prog1 ,(cadr frobs) + ,(loop-make-psetq (cddr frobs)))))))) + + +(defun loop-make-desetq (var-val-pairs) + (if (null var-val-pairs) + nil + (cons (if *loop-destructuring-hooks* + (cadr *loop-destructuring-hooks*) + 'loop-really-desetq) + var-val-pairs))) + + +(defvar *loop-desetq-temporary* + (make-symbol "LOOP-DESETQ-TEMP")) + + +(defmacro loop-really-desetq (&environment env &rest var-val-pairs) + (labels ((find-non-null (var) + ;; see if there's any non-null thing here + ;; recurse if the list element is itself a list + (do ((tail var)) ((not (consp tail)) tail) + (when (find-non-null (pop tail)) (return t)))) + (loop-desetq-internal (var val &optional temp) + ;; returns a list of actions to be performed + (typecase var + (null + (when (consp val) + ;; don't lose possible side-effects + (if (eq (car val) 'prog1) + ;; these can come from psetq or desetq below. + ;; throw away the value, keep the side-effects. + ;;Special case is for handling an expanded POP. + (mapcan #'(lambda (x) + (and (consp x) + (or (not (eq (car x) 'car)) + (not (symbolp (cadr x))) + (not (symbolp (setq x (macroexpand x env))))) + (cons x nil))) + (cdr val)) + `(,val)))) + (cons + (let* ((car (car var)) + (cdr (cdr var)) + (car-non-null (find-non-null car)) + (cdr-non-null (find-non-null cdr))) + (when (or car-non-null cdr-non-null) + (if cdr-non-null + (let* ((temp-p temp) + (temp (or temp *loop-desetq-temporary*)) + (body #+LOOP-Prefer-POP `(,@(loop-desetq-internal + car + `(prog1 (car ,temp) + (setq ,temp (cdr ,temp)))) + ,@(loop-desetq-internal cdr temp temp)) + #-LOOP-Prefer-POP `(,@(loop-desetq-internal car `(car ,temp)) + (setq ,temp (cdr ,temp)) + ,@(loop-desetq-internal cdr temp temp)))) + (if temp-p + `(,@(unless (eq temp val) + `((setq ,temp ,val))) + ,@body) + `((let ((,temp ,val)) + ,@body)))) + ;; no cdring to do + (loop-desetq-internal car `(car ,val) temp))))) + (otherwise + (unless (eq var val) + `((setq ,var ,val))))))) + (do ((actions)) + ((null var-val-pairs) + (if (null (cdr actions)) (car actions) `(progn ,@(nreverse actions)))) + (setq actions (revappend + (loop-desetq-internal (pop var-val-pairs) (pop var-val-pairs)) + actions))))) + + +;;;; LOOP-local variables + +;;;This is the "current" pointer into the LOOP source code. +(defvar *loop-source-code*) + + +;;;This is the pointer to the original, for things like NAMED that +;;;insist on being in a particular position +(defvar *loop-original-source-code*) + + +;;;This is *loop-source-code* as of the "last" clause. It is used +;;;primarily for generating error messages (see loop-error, loop-warn). +(defvar *loop-source-context*) + + +;;;List of names for the LOOP, supplied by the NAMED clause. +(defvar *loop-names*) + +;;;The macroexpansion environment given to the macro. +(defvar *loop-macro-environment*) + +;;;This holds variable names specified with the USING clause. +;;; See LOOP-NAMED-VARIABLE. +(defvar *loop-named-variables*) + +;;; LETlist-like list being accumulated for one group of parallel bindings. +(defvar *loop-variables*) + +;;;List of declarations being accumulated in parallel with +;;;*loop-variables*. +(defvar *loop-declarations*) + +;;;Used by LOOP for destructuring binding, if it is doing that itself. +;;; See loop-make-variable. +(defvar *loop-desetq-crocks*) + +;;; List of wrapping forms, innermost first, which go immediately inside +;;; the current set of parallel bindings being accumulated in +;;; *loop-variables*. The wrappers are appended onto a body. E.g., +;;; this list could conceivably has as its value ((with-open-file (g0001 +;;; g0002 ...))), with g0002 being one of the bindings in +;;; *loop-variables* (this is why the wrappers go inside of the variable +;;; bindings). +(defvar *loop-wrappers*) + +;;;This accumulates lists of previous values of *loop-variables* and the +;;;other lists above, for each new nesting of bindings. See +;;;loop-bind-block. +(defvar *loop-bind-stack*) + +;;;This is a LOOP-global variable for the (obsolete) NODECLARE clause +;;;which inhibits LOOP from actually outputting a type declaration for +;;;an iteration (or any) variable. +(defvar *loop-nodeclare*) + +;;;This is simply a list of LOOP iteration variables, used for checking +;;;for duplications. +(defvar *loop-iteration-variables*) + + +;;;List of prologue forms of the loop, accumulated in reverse order. +(defvar *loop-prologue*) + +(defvar *loop-before-loop*) +(defvar *loop-body*) +(defvar *loop-after-body*) + +;;;This is T if we have emitted any body code, so that iteration driving +;;;clauses can be disallowed. This is not strictly the same as +;;;checking *loop-body*, because we permit some clauses such as RETURN +;;;to not be considered "real" body (so as to permit the user to "code" +;;;an abnormal return value "in loop"). +(defvar *loop-emitted-body*) + + +;;;List of epilogue forms (supplied by FINALLY generally), accumulated +;;; in reverse order. +(defvar *loop-epilogue*) + +;;;List of epilogue forms which are supplied after the above "user" +;;;epilogue. "normal" termination return values are provide by putting +;;;the return form in here. Normally this is done using +;;;loop-emit-final-value, q.v. +(defvar *loop-after-epilogue*) + +;;;The "culprit" responsible for supplying a final value from the loop. +;;;This is so loop-emit-final-value can moan about multiple return +;;;values being supplied. +(defvar *loop-final-value-culprit*) + +;;;If not NIL, we are in some branch of a conditional. Some clauses may +;;;be disallowed. +(defvar *loop-inside-conditional*) + +;;;If not NIL, this is a temporary bound around the loop for holding the +;;;temporary value for "it" in things like "when (f) collect it". It +;;;may be used as a supertemporary by some other things. +(defvar *loop-when-it-variable*) + +;;;Sometimes we decide we need to fold together parts of the loop, but +;;;some part of the generated iteration code is different for the first +;;;and remaining iterations. This variable will be the temporary which +;;;is the flag used in the loop to tell whether we are in the first or +;;;remaining iterations. +(defvar *loop-never-stepped-variable*) + +;;;List of all the value-accumulation descriptor structures in the loop. +;;; See loop-get-collection-info. +(defvar *loop-collection-cruft*) ; for multiple COLLECTs (etc) + + +;;;; Code Analysis Stuff + + +(defun loop-constant-fold-if-possible (form &optional expected-type) + #+Genera (declare (values new-form constantp constant-value)) + (let ((new-form form) (constantp nil) (constant-value nil)) + #+Genera (setq new-form (compiler:optimize-form form *loop-macro-environment* + :repeat t + :do-macro-expansion t + :do-named-constants t + :do-inline-forms t + :do-optimizers t + :do-constant-folding t + :do-function-args t) + constantp (constantp new-form *loop-macro-environment*) + constant-value (and constantp (lt:evaluate-constant new-form *loop-macro-environment*))) + #-Genera (when (setq constantp (constantp new-form)) + (setq constant-value (eval new-form))) + (when (and constantp expected-type) + (unless (typep constant-value expected-type) + (loop-warn "The form ~S evaluated to ~S, which was not of the anticipated type ~S." + form constant-value expected-type) + (setq constantp nil constant-value nil))) + (values new-form constantp constant-value))) + + +(defun loop-constantp (form) + #+Genera (constantp form *loop-macro-environment*) + #-Genera (constantp form)) + + +;;;; LOOP Iteration Optimization + +(defvar *loop-duplicate-code* + nil) + + +(defvar *loop-iteration-flag-variable* + (make-symbol "LOOP-NOT-FIRST-TIME")) + + +(defun loop-code-duplication-threshold (env) + (multiple-value-bind (speed space) (loop-optimization-quantities env) + (+ 40 (* (- speed space) 10)))) + + +(defmacro loop-body (&environment env + prologue + before-loop + main-body + after-loop + epilogue + &aux rbefore rafter flagvar) + (unless (= (length before-loop) (length after-loop)) + (error "LOOP-BODY called with non-synched before- and after-loop lists.")) + ;;All our work is done from these copies, working backwards from the end: + (setq rbefore (reverse before-loop) rafter (reverse after-loop)) + (labels ((psimp (l) + (let ((ans nil)) + (dolist (x l) + (when x + (push x ans) + (when (and (consp x) (member (car x) '(go return return-from))) + (return nil)))) + (nreverse ans))) + (pify (l) (if (null (cdr l)) (car l) `(progn ,@l))) + (makebody () + (let ((form `(tagbody + ;; ANSI CL 6.1.7.2 says that initially clauses are + ;; evaluated in the loop prologue, which precedes + ;; all loop code except for the initial settings + ;; provided by with, for, or as. + ,@(psimp (append (nreverse rbefore) prologue)) + next-loop + ,@(psimp (append main-body (nreconc rafter `((go next-loop))))) + end-loop + ,@(psimp epilogue)))) + (if flagvar `(let ((,flagvar nil)) ,form) form)))) + (when (or *loop-duplicate-code* (not rbefore)) + (return-from loop-body (makebody))) + ;; This outer loop iterates once for each not-first-time flag test generated + ;; plus once more for the forms that don't need a flag test + (do ((threshold (loop-code-duplication-threshold env))) (nil) + (declare (fixnum threshold)) + ;; Go backwards from the ends of before-loop and after-loop merging all the equivalent + ;; forms into the body. + (do () ((or (null rbefore) (not (equal (car rbefore) (car rafter))))) + (push (pop rbefore) main-body) + (pop rafter)) + (unless rbefore (return (makebody))) + ;; The first forms in rbefore & rafter (which are the chronologically + ;; last forms in the list) differ, therefore they cannot be moved + ;; into the main body. If everything that chronologically precedes + ;; them either differs or is equal but is okay to duplicate, we can + ;; just put all of rbefore in the prologue and all of rafter after + ;; the body. Otherwise, there is something that is not okay to + ;; duplicate, so it and everything chronologically after it in + ;; rbefore and rafter must go into the body, with a flag test to + ;; distinguish the first time around the loop from later times. + ;; What chronologically precedes the non-duplicatable form will + ;; be handled the next time around the outer loop. + (do ((bb rbefore (cdr bb)) (aa rafter (cdr aa)) (lastdiff nil) (count 0) (inc nil)) + ((null bb) (return-from loop-body (makebody))) ;Did it. + (cond ((not (equal (car bb) (car aa))) (setq lastdiff bb count 0)) + ((or (not (setq inc (estimate-code-size (car bb) env))) + (> (incf count inc) threshold)) + ;; Ok, we have found a non-duplicatable piece of code. Everything + ;; chronologically after it must be in the central body. + ;; Everything chronologically at and after lastdiff goes into the + ;; central body under a flag test. + (let ((then nil) (else nil)) + (do () (nil) + (push (pop rbefore) else) + (push (pop rafter) then) + (when (eq rbefore (cdr lastdiff)) (return))) + (unless flagvar + (push `(setq ,(setq flagvar *loop-iteration-flag-variable*) t) else)) + (push `(if ,flagvar ,(pify (psimp then)) ,(pify (psimp else))) + main-body)) + ;; Everything chronologically before lastdiff until the non-duplicatable form (car bb) + ;; is the same in rbefore and rafter so just copy it into the body + (do () (nil) + (pop rafter) + (push (pop rbefore) main-body) + (when (eq rbefore (cdr bb)) (return))) + (return))))))) + + + +(defun duplicatable-code-p (expr env) + (if (null expr) 0 + (let ((ans (estimate-code-size expr env))) + (declare (fixnum ans)) + ;;@@@@ Use (DECLARATION-INFORMATION 'OPTIMIZE ENV) here to get an alist of + ;; optimize quantities back to help quantify how much code we are willing to + ;; duplicate. + ans))) + + +(defvar *special-code-sizes* + '((return 0) (progn 0) + (null 1) (not 1) (eq 1) (car 1) (cdr 1) + (when 1) (unless 1) (if 1) + (caar 2) (cadr 2) (cdar 2) (cddr 2) + (caaar 3) (caadr 3) (cadar 3) (caddr 3) (cdaar 3) (cdadr 3) (cddar 3) (cdddr 3) + (caaaar 4) (caaadr 4) (caadar 4) (caaddr 4) + (cadaar 4) (cadadr 4) (caddar 4) (cadddr 4) + (cdaaar 4) (cdaadr 4) (cdadar 4) (cdaddr 4) + (cddaar 4) (cddadr 4) (cdddar 4) (cddddr 4))) + + +(defvar *estimate-code-size-punt* + '(block + do do* dolist + flet + labels lambda let let* locally + macrolet multiple-value-bind + prog prog* + symbol-macrolet + tagbody + unwind-protect + with-open-file)) + + +(defun destructuring-size (x) + (do ((x x (cdr x)) (n 0 (+ (destructuring-size (car x)) n))) + ((atom x) (+ n (if (null x) 0 1))))) + + +(defun estimate-code-size (x env) + (catch 'estimate-code-size + (estimate-code-size-1 x env))) + + +(defun estimate-code-size-1 (x env) + (flet ((list-size (l) + (let ((n 0)) + (declare (fixnum n)) + (dolist (x l n) (incf n (estimate-code-size-1 x env)))))) + ;;@@@@ ???? (declare (function list-size (list) fixnum)) + (cond ((constantp x #+Genera env) 1) + ((symbolp x) (multiple-value-bind (new-form expanded-p) (macroexpand-1 x env) + (if expanded-p (estimate-code-size-1 new-form env) 1))) + ((atom x) 1) ;??? self-evaluating??? + ((symbolp (car x)) + (let ((fn (car x)) (tem nil) (n 0)) + (declare (symbol fn) (fixnum n)) + (macrolet ((f (overhead &optional (args nil args-p)) + `(the fixnum (+ (the fixnum ,overhead) + (the fixnum (list-size ,(if args-p args '(cdr x)))))))) + (cond ((setq tem (get fn 'estimate-code-size)) + (typecase tem + (fixnum (f tem)) + (t (funcall tem x env)))) + ((setq tem (assoc fn *special-code-sizes*)) (f (second tem))) + #+Genera + ((eq fn 'compiler:invisible-references) (list-size (cddr x))) + ((eq fn 'cond) + (dolist (clause (cdr x) n) (incf n (list-size clause)) (incf n))) + ((eq fn 'desetq) + (do ((l (cdr x) (cdr l))) ((null l) n) + (setq n (+ n (destructuring-size (car l)) (estimate-code-size-1 (cadr l) env))))) + ((member fn '(setq psetq)) + (do ((l (cdr x) (cdr l))) ((null l) n) + (setq n (+ n (estimate-code-size-1 (cadr l) env) 1)))) + ((eq fn 'go) 1) + ((eq fn 'function) + ;;This skirts the issue of implementationally-defined lambda macros + ;; by recognizing CL function names and nothing else. + #-cmu 1 + #+cmu (if (ext:valid-function-name-p (cadr x)) + 1 + (throw 'duplicatable-code-p nil))) + ((eq fn 'multiple-value-setq) (f (length (second x)) (cddr x))) + ((eq fn 'return-from) (1+ (estimate-code-size-1 (third x) env))) + ((or (special-operator-p fn) (member fn *estimate-code-size-punt*)) + (throw 'estimate-code-size nil)) + (t (multiple-value-bind (new-form expanded-p) (macroexpand-1 x env) + (if expanded-p + (estimate-code-size-1 new-form env) + (f 3)))))))) + (t (throw 'estimate-code-size nil))))) + + +;;;; Loop Errors + + +(defun loop-context () + (do ((l *loop-source-context* (cdr l)) (new nil (cons (car l) new))) + ((eq l (cdr *loop-source-code*)) (nreverse new)))) + + +(defun loop-error (format-string &rest format-args) + #+(or Genera CLOE) (declare (dbg:error-reporter)) + #+Genera (setq format-args (copy-list format-args)) ;Don't ask. + #+cmu + (kernel:simple-program-error "~?~%Current LOOP context:~{ ~S~}." + format-string format-args (loop-context)) + #-cmu + (error "~?~%Current LOOP context:~{ ~S~}." + format-string format-args (loop-context))) + + +(defun loop-warn (format-string &rest format-args) + (warn "~?~%Current LOOP context:~{ ~S~}." format-string format-args (loop-context))) + + +(defun loop-check-data-type (specified-type required-type + &optional (default-type required-type)) + (if (null specified-type) + default-type + (multiple-value-bind (a b) (subtypep specified-type required-type) + (cond ((not b) + (loop-warn "LOOP couldn't verify that ~S is a subtype of the required type ~S." + specified-type required-type)) + ((not a) + (loop-error "Specified data type ~S is not a subtype of ~S." + specified-type required-type))) + specified-type))) + + +;;;INTERFACE: Traditional, ANSI, Lucid. +(defmacro loop-finish () + "Causes the iteration to terminate \"normally\", the same as implicit +termination by an iteration driving clause, or by use of WHILE or +UNTIL -- the epilogue code (if any) will be run, and any implicitly +collected result will be returned as the value of the LOOP." + '(go end-loop)) + + + +(defun subst-gensyms-for-nil (tree) + (declare (special *ignores*)) + (cond + ((null tree) (car (push (loop-gentemp) *ignores*))) + ((atom tree) tree) + (t (cons (subst-gensyms-for-nil (car tree)) + (subst-gensyms-for-nil (cdr tree)))))) + +(defun loop-build-destructuring-bindings (crocks forms) + (if crocks + (let ((*ignores* ())) + (declare (special *ignores*)) + `((destructuring-bind ,(subst-gensyms-for-nil (car crocks)) + ,(cadr crocks) + (declare (ignore ,@*ignores*)) + ,@(loop-build-destructuring-bindings (cddr crocks) forms)))) + forms)) + +(defun loop-translate (*loop-source-code* *loop-macro-environment* *loop-universe*) + (let ((*loop-original-source-code* *loop-source-code*) + (*loop-source-context* nil) + (*loop-iteration-variables* nil) + (*loop-variables* nil) + (*loop-nodeclare* nil) + (*loop-named-variables* nil) + (*loop-declarations* nil) + (*loop-desetq-crocks* nil) + (*loop-bind-stack* nil) + (*loop-prologue* nil) + (*loop-wrappers* nil) + (*loop-before-loop* nil) + (*loop-body* nil) + (*loop-emitted-body* nil) + (*loop-after-body* nil) + (*loop-epilogue* nil) + (*loop-after-epilogue* nil) + (*loop-final-value-culprit* nil) + (*loop-inside-conditional* nil) + (*loop-when-it-variable* nil) + (*loop-never-stepped-variable* nil) + (*loop-names* nil) + (*loop-collection-cruft* nil)) + (loop-iteration-driver) + (loop-bind-block) + (let ((answer `(loop-body + ,(nreverse *loop-prologue*) + ,(nreverse *loop-before-loop*) + ,(nreverse *loop-body*) + ,(nreverse *loop-after-body*) + ,(nreconc *loop-epilogue* (nreverse *loop-after-epilogue*))))) + (dolist (entry *loop-bind-stack*) + (let ((vars (first entry)) + (dcls (second entry)) + (crocks (third entry)) + (wrappers (fourth entry))) + (dolist (w wrappers) + (setq answer (append w (list answer)))) + (when (or vars dcls crocks) + (let ((forms (list answer))) + ;;(when crocks (push crocks forms)) + (when dcls (push `(declare ,@dcls) forms)) + (setq answer `(,(cond ((not vars) 'locally) + (*loop-destructuring-hooks* (first *loop-destructuring-hooks*)) + (t 'let)) + ,vars + ,@(loop-build-destructuring-bindings crocks forms))))))) + (if *loop-names* + (do () ((null (car *loop-names*)) answer) + (setq answer `(block ,(pop *loop-names*) ,answer))) + `(block nil ,answer))))) + + +(defun loop-iteration-driver () + (do () ((null *loop-source-code*)) + (let ((keyword (car *loop-source-code*)) (tem nil)) + (cond ((not (symbolp keyword)) + (loop-error "~S found where LOOP keyword expected." keyword)) + (t (setq *loop-source-context* *loop-source-code*) + (loop-pop-source) + (cond ((setq tem (loop-lookup-keyword keyword (loop-universe-keywords *loop-universe*))) + ;;It's a "miscellaneous" toplevel LOOP keyword (do, collect, named, etc.) + (apply (symbol-function (first tem)) (rest tem))) + ((setq tem (loop-lookup-keyword keyword (loop-universe-iteration-keywords *loop-universe*))) + (loop-hack-iteration tem)) + ((loop-tmember keyword '(and else)) + ;; Alternative is to ignore it, ie let it go around to the next keyword... + (loop-error "Secondary clause misplaced at top level in LOOP macro: ~S ~S ~S ..." + keyword (car *loop-source-code*) (cadr *loop-source-code*))) + (t (loop-error "~S is an unknown keyword in LOOP macro." keyword)))))))) + + + +(defun loop-pop-source () + (if *loop-source-code* + (pop *loop-source-code*) + (loop-error "LOOP source code ran out when another token was expected."))) + + +(defun loop-get-compound-form () + (let ((form (loop-get-form))) + (unless (consp form) + (loop-error "Compound form expected, but found ~A." form)) + form)) + +(defun loop-get-progn () + (do ((forms (list (loop-get-compound-form)) + (cons (loop-get-compound-form) forms)) + (nextform (car *loop-source-code*) + (car *loop-source-code*))) + ((atom nextform) + (if (null (cdr forms)) (car forms) (cons 'progn (nreverse forms)))))) + + +(defun loop-get-form () + (if *loop-source-code* + (loop-pop-source) + (loop-error "LOOP code ran out where a form was expected."))) + + +(defun loop-construct-return (form) + `(return-from ,(car *loop-names*) ,form)) + + +(defun loop-pseudo-body (form) + (cond ((or *loop-emitted-body* *loop-inside-conditional*) (push form *loop-body*)) + (t (push form *loop-before-loop*) (push form *loop-after-body*)))) + +(defun loop-emit-body (form) + (setq *loop-emitted-body* t) + (loop-pseudo-body form)) + +(defun loop-emit-final-value (&optional (form nil form-supplied-p)) + (when form-supplied-p + (push (loop-construct-return form) *loop-after-epilogue*)) + (when *loop-final-value-culprit* + (loop-warn "LOOP clause is providing a value for the iteration,~@ + however one was already established by a ~S clause." + *loop-final-value-culprit*)) + (setq *loop-final-value-culprit* (car *loop-source-context*))) + + +(defun loop-disallow-conditional (&optional kwd) + #+(or Genera CLOE) (declare (dbg:error-reporter)) + (when *loop-inside-conditional* + (loop-error "~:[This LOOP~;The LOOP ~:*~S~] clause is not permitted inside a conditional." kwd))) + +(defun loop-disallow-anonymous-collectors () + (when (find-if-not 'loop-collector-name *loop-collection-cruft*) + (loop-error "This LOOP clause is not permitted with anonymous collectors."))) + +(defun loop-disallow-aggregate-booleans () + (when (loop-tmember *loop-final-value-culprit* '(always never thereis)) + (loop-error "This anonymous collection LOOP clause is not permitted with aggregate booleans."))) + + + +;;;; Loop Types + + +(defun loop-typed-init (data-type) + (when (and data-type (subtypep data-type 'number)) + (if (or (subtypep data-type 'float) (subtypep data-type '(complex float))) + (coerce 0 data-type) + 0))) + + +(defun loop-optional-type (&optional variable) + ;;No variable specified implies that no destructuring is permissible. + (and *loop-source-code* ;Don't get confused by NILs... + (let ((z (car *loop-source-code*))) + (cond ((loop-tequal z 'of-type) + ;;This is the syntactically unambigous form in that the form of the + ;; type specifier does not matter. Also, it is assumed that the + ;; type specifier is unambiguously, and without need of translation, + ;; a common lisp type specifier or pattern (matching the variable) thereof. + (loop-pop-source) + (loop-pop-source)) + + ((symbolp z) + ;;This is the (sort of) "old" syntax, even though we didn't used to support all of + ;; these type symbols. + (let ((type-spec (or (gethash z (loop-universe-type-symbols *loop-universe*)) + (gethash (symbol-name z) (loop-universe-type-keywords *loop-universe*))))) + (when type-spec + (loop-pop-source) + type-spec))) + (t + ;;This is our sort-of old syntax. But this is only valid for when we are destructuring, + ;; so we will be compulsive (should we really be?) and require that we in fact be + ;; doing variable destructuring here. We must translate the old keyword pattern typespec + ;; into a fully-specified pattern of real type specifiers here. + (if (consp variable) + (unless (consp z) + (loop-error + "~S found where a LOOP keyword, LOOP type keyword, or LOOP type pattern expected." + z)) + (loop-error "~S found where a LOOP keyword or LOOP type keyword expected." z)) + (loop-pop-source) + (labels ((translate (k v) + (cond ((null k) nil) + ((atom k) + (replicate + (or (gethash k (loop-universe-type-symbols *loop-universe*)) + (gethash (symbol-name k) (loop-universe-type-keywords *loop-universe*)) + (loop-error + "Destructuring type pattern ~S contains unrecognized type keyword ~S." + z k)) + v)) + ((atom v) + (loop-error + "Destructuring type pattern ~S doesn't match variable pattern ~S." + z variable)) + (t (cons (translate (car k) (car v)) (translate (cdr k) (cdr v)))))) + (replicate (typ v) + (if (atom v) typ (cons (replicate typ (car v)) (replicate typ (cdr v)))))) + (translate z variable))))))) + + + +;;;; Loop Variables + + +(defun loop-bind-block () + (when (or *loop-variables* *loop-declarations* *loop-wrappers*) + (push (list (nreverse *loop-variables*) *loop-declarations* *loop-desetq-crocks* *loop-wrappers*) + *loop-bind-stack*) + (setq *loop-variables* nil + *loop-declarations* nil + *loop-desetq-crocks* nil + *loop-wrappers* nil))) + +(defun loop-variable-p (name) + (do ((entry *loop-bind-stack* (cdr entry))) (nil) + (cond ((null entry) + (return nil)) + ((assoc name (caar entry) :test #'eq) + (return t))))) + +(defun loop-make-variable (name initialization dtype &optional iteration-variable-p) + (cond ((null name) + (cond ((not (null initialization)) + (push (list (setq name (loop-gentemp 'loop-ignore-)) + initialization) + *loop-variables*) + (push `(ignore ,name) *loop-declarations*)))) + ((atom name) + (cond (iteration-variable-p + (if (member name *loop-iteration-variables*) + (loop-error "Duplicated LOOP iteration variable ~S." name) + (push name *loop-iteration-variables*))) + ((assoc name *loop-variables*) + (loop-error "Duplicated variable ~S in LOOP parallel binding." name))) + (unless (symbolp name) + (loop-error "Bad variable ~S somewhere in LOOP." name)) + (loop-declare-variable name dtype) + ;; We use ASSOC on this list to check for duplications (above), + ;; so don't optimize out this list: + (push (list name (or initialization (loop-typed-init dtype))) + *loop-variables*)) + (initialization + (cond (*loop-destructuring-hooks* + (loop-declare-variable name dtype) + (push (list name initialization) *loop-variables*)) + (t (let ((newvar (loop-gentemp 'loop-destructure-))) + (loop-declare-variable name dtype) + (push (list newvar initialization) *loop-variables*) + ;; *LOOP-DESETQ-CROCKS* gathered in reverse order. + (setq *loop-desetq-crocks* + (list* name newvar *loop-desetq-crocks*)) + #+ignore + (loop-make-variable name nil dtype iteration-variable-p))))) + (t (let ((tcar nil) (tcdr nil)) + (if (atom dtype) (setq tcar (setq tcdr dtype)) + (setq tcar (car dtype) tcdr (cdr dtype))) + (loop-make-variable (car name) nil tcar iteration-variable-p) + (loop-make-variable (cdr name) nil tcdr iteration-variable-p)))) + name) + + +(defun loop-make-iteration-variable (name initialization dtype) + (when (and name (loop-variable-p name)) + (loop-error "Variable ~S has already been used" name)) + (loop-make-variable name initialization dtype t)) + + +(defun loop-declare-variable (name dtype) + (cond ((or (null name) (null dtype) (eq dtype t)) nil) + ((symbolp name) + (unless (or (eq dtype t) (member (the symbol name) *loop-nodeclare*)) + (let ((dtype (let ((init (loop-typed-init dtype))) + (if (typep init dtype) + dtype + `(or (member ,init) ,dtype))))) + (push `(type ,dtype ,name) *loop-declarations*)))) + ((consp name) + (cond ((consp dtype) + (loop-declare-variable (car name) (car dtype)) + (loop-declare-variable (cdr name) (cdr dtype))) + (t (loop-declare-variable (car name) dtype) + (loop-declare-variable (cdr name) dtype)))) + (t (error "Invalid LOOP variable passed in: ~S." name)))) + + +(defun loop-maybe-bind-form (form data-type) + (if (loop-constantp form) + form + (loop-make-variable (loop-gentemp 'loop-bind-) form data-type))) + + + +(defun loop-do-if (for negatep) + (let ((form (loop-get-form)) + (it-p nil) + (first-clause-p t) then else) + (let ((*loop-inside-conditional* t)) + (flet ((get-clause (for) + (do ((body nil)) (nil) + (let ((key (car *loop-source-code*)) (*loop-body* nil) data) + (cond ((not (symbolp key)) + (loop-error + "~S found where keyword expected getting LOOP clause after ~S." + key for)) + (t (setq *loop-source-context* *loop-source-code*) + (loop-pop-source) + (when (and (loop-tequal (car *loop-source-code*) 'it) + first-clause-p) + (setq *loop-source-code* + (cons (or it-p (setq it-p (loop-when-it-variable))) + (cdr *loop-source-code*)))) + (cond ((or (not (setq data (loop-lookup-keyword + key (loop-universe-keywords *loop-universe*)))) + (progn (apply (symbol-function (car data)) (cdr data)) + (null *loop-body*))) + (loop-error + "~S does not introduce a LOOP clause that can follow ~S." + key for)) + (t (setq body (nreconc *loop-body* body))))))) + (setq first-clause-p nil) + (if (loop-tequal (car *loop-source-code*) :and) + (loop-pop-source) + (return (if (cdr body) `(progn ,@(nreverse body)) (car body))))))) + (setq then (get-clause for)) + (setq else (when (loop-tequal (car *loop-source-code*) :else) + (loop-pop-source) + (list (get-clause :else))))) + (when (loop-tequal (car *loop-source-code*) :end) + (loop-pop-source)) + (when it-p + (setq form `(setq ,it-p ,form)))) + (loop-pseudo-body + `(if ,(if negatep `(not ,form) form) + ,then + ,@else)))) + + +(defun loop-do-initially () + (loop-disallow-conditional :initially) + (push (loop-get-progn) *loop-prologue*)) + +(defun loop-do-finally () + (loop-disallow-conditional :finally) + (push (loop-get-progn) *loop-epilogue*)) + +(defun loop-do-do () + (loop-emit-body (loop-get-progn))) + +(defun loop-do-named () + (let ((name (loop-pop-source))) + (unless (symbolp name) + (loop-error "~S is an invalid name for your LOOP." name)) + (when (or *loop-before-loop* *loop-body* *loop-after-epilogue* *loop-inside-conditional*) + (loop-error "The NAMED ~S clause occurs too late." name)) + (when *loop-names* + (loop-error "You may only use one NAMED clause in your loop: NAMED ~S ... NAMED ~S." + (car *loop-names*) name)) + (setq *loop-names* (list name nil)))) + +(defun loop-do-return () + (loop-pseudo-body (loop-construct-return (loop-get-form)))) + + +;;;; Value Accumulation: List + + +(defstruct (loop-collector + (:copier nil) + (:predicate nil)) + name + class + (history nil) + (tempvars nil) + dtype + (data nil)) ;collector-specific data + + +(defun loop-get-collection-info (collector class default-type) + (let ((form (loop-get-form)) + (dtype (and (not (loop-universe-ansi *loop-universe*)) (loop-optional-type))) + (name (when (loop-tequal (car *loop-source-code*) 'into) + (loop-pop-source) + (loop-pop-source)))) + (when (not (symbolp name)) + (loop-error "Value accumulation recipient name, ~S, is not a symbol." name)) + (unless name + (loop-disallow-aggregate-booleans)) + (unless dtype + (setq dtype (or (loop-optional-type) default-type))) + (let ((cruft (find (the symbol name) *loop-collection-cruft* + :key #'loop-collector-name))) + (cond ((not cruft) + (when (and name (loop-variable-p name)) + (loop-error "Variable ~S cannot be used in INTO clause" name)) + (push (setq cruft (make-loop-collector + :name name :class class + :history (list collector) :dtype dtype)) + *loop-collection-cruft*)) + (t (unless (eq (loop-collector-class cruft) class) + (loop-error + "Incompatible kinds of LOOP value accumulation specified for collecting~@ + ~:[as the value of the LOOP~;~:*INTO ~S~]: ~S and ~S." + name (car (loop-collector-history cruft)) collector)) + (unless (equal dtype (loop-collector-dtype cruft)) + (loop-warn + "Unequal datatypes specified in different LOOP value accumulations~@ + into ~S: ~S and ~S." + name dtype (loop-collector-dtype cruft)) + (when (eq (loop-collector-dtype cruft) t) + (setf (loop-collector-dtype cruft) dtype))) + (push collector (loop-collector-history cruft)))) + (values cruft form)))) + + +(defun loop-list-collection (specifically) ;NCONC, LIST, or APPEND + (multiple-value-bind (lc form) (loop-get-collection-info specifically 'list 'list) + (let ((tempvars (loop-collector-tempvars lc))) + (unless tempvars + (setf (loop-collector-tempvars lc) + (setq tempvars (list* (loop-gentemp 'loop-list-head-) + (loop-gentemp 'loop-list-tail-) + (and (loop-collector-name lc) + (list (loop-collector-name lc)))))) + (push `(with-loop-list-collection-head ,tempvars) *loop-wrappers*) + (unless (loop-collector-name lc) + (loop-emit-final-value `(loop-collect-answer ,(car tempvars) ,@(cddr tempvars))))) + (ecase specifically + (list (setq form `(list ,form))) + (nconc nil) + (append (unless (and (consp form) (eq (car form) 'list)) + (setq form `(loop-copylist* ,form))))) + (loop-emit-body `(loop-collect-rplacd ,tempvars ,form))))) + + +;;;; Value Accumulation: max, min, sum, count. + + + +(defun loop-sum-collection (specifically required-type default-type) ;SUM, COUNT + (multiple-value-bind (lc form) + (loop-get-collection-info specifically 'sum default-type) + (loop-check-data-type (loop-collector-dtype lc) required-type) + (let ((tempvars (loop-collector-tempvars lc))) + (unless tempvars + (setf (loop-collector-tempvars lc) + (setq tempvars (list (loop-make-variable + (or (loop-collector-name lc) + (loop-gentemp 'loop-sum-)) + nil (loop-collector-dtype lc))))) + (unless (loop-collector-name lc) + (loop-emit-final-value (car (loop-collector-tempvars lc))))) + (loop-emit-body + (if (eq specifically 'count) + `(when ,form + (setq ,(car tempvars) + ,(hide-variable-reference t (car tempvars) `(1+ ,(car tempvars))))) + `(setq ,(car tempvars) + (+ ,(hide-variable-reference t (car tempvars) (car tempvars)) + ,form))))))) + + + +(defun loop-maxmin-collection (specifically) + (multiple-value-bind (lc form) + (loop-get-collection-info specifically 'maxmin *loop-real-data-type*) + (loop-check-data-type (loop-collector-dtype lc) *loop-real-data-type*) + (let ((data (loop-collector-data lc))) + (unless data + (setf (loop-collector-data lc) + (setq data (make-loop-minimax + (or (loop-collector-name lc) (loop-gentemp 'loop-maxmin-)) + (loop-collector-dtype lc)))) + (unless (loop-collector-name lc) + (loop-emit-final-value (loop-minimax-answer-variable data)))) + (loop-note-minimax-operation specifically data) + (push `(with-minimax-value ,data) *loop-wrappers*) + (loop-emit-body `(loop-accumulate-minimax-value ,data ,specifically ,form)) + ))) + + +;;;; Value Accumulation: Aggregate Booleans + +;;;ALWAYS and NEVER. +;;; Under ANSI these are not permitted to appear under conditionalization. +(defun loop-do-always (restrictive negate) + (let ((form (loop-get-form))) + (when restrictive (loop-disallow-conditional)) + (loop-disallow-anonymous-collectors) + (loop-emit-body `(,(if negate 'when 'unless) ,form + ,(loop-construct-return nil))) + (loop-emit-final-value t))) + + + +;;;THERIS. +;;; Under ANSI this is not permitted to appear under conditionalization. +(defun loop-do-thereis (restrictive) + (when restrictive (loop-disallow-conditional)) + (loop-disallow-anonymous-collectors) + (loop-emit-final-value) + (loop-emit-body `(when (setq ,(loop-when-it-variable) ,(loop-get-form)) + ,(loop-construct-return *loop-when-it-variable*)))) + + +(defun loop-do-while (negate kwd &aux (form (loop-get-form))) + (loop-disallow-conditional kwd) + (loop-pseudo-body `(,(if negate 'when 'unless) ,form (go end-loop)))) + + +(defun loop-do-with () + (loop-disallow-conditional :with) + (do ((var) (val) (dtype)) (nil) + (setq var (loop-pop-source) + dtype (loop-optional-type var) + val (cond ((loop-tequal (car *loop-source-code*) :=) + (loop-pop-source) + (loop-get-form)) + (t nil))) + (when (and var (loop-variable-p var)) + (loop-error "Variable ~S has already been used" var)) + (loop-make-variable var val dtype) + (if (loop-tequal (car *loop-source-code*) :and) + (loop-pop-source) + (return (loop-bind-block))))) + + +;;;; The iteration driver + +(defun loop-hack-iteration (entry) + (flet ((make-endtest (list-of-forms) + (cond ((null list-of-forms) nil) + ((member t list-of-forms) '(go end-loop)) + (t `(when ,(if (null (cdr (setq list-of-forms (nreverse list-of-forms)))) + (car list-of-forms) + (cons 'or list-of-forms)) + (go end-loop)))))) + (do ((pre-step-tests nil) + (steps nil) + (post-step-tests nil) + (pseudo-steps nil) + (pre-loop-pre-step-tests nil) + (pre-loop-steps nil) + (pre-loop-post-step-tests nil) + (pre-loop-pseudo-steps nil) + (tem) (data)) + (nil) + ;; Note we collect endtests in reverse order, but steps in correct + ;; order. MAKE-ENDTEST does the nreverse for us. + (setq tem (setq data (apply (symbol-function (first entry)) (rest entry)))) + (and (car tem) (push (car tem) pre-step-tests)) + (setq steps (nconc steps (loop-copylist* (car (setq tem (cdr tem)))))) + (and (car (setq tem (cdr tem))) (push (car tem) post-step-tests)) + (setq pseudo-steps (nconc pseudo-steps (loop-copylist* (car (setq tem (cdr tem)))))) + (setq tem (cdr tem)) + (when *loop-emitted-body* + (loop-error "Iteration in LOOP follows body code.")) + (unless tem (setq tem data)) + (when (car tem) (push (car tem) pre-loop-pre-step-tests)) + (setq pre-loop-steps (nconc pre-loop-steps (loop-copylist* (car (setq tem (cdr tem)))))) + (when (car (setq tem (cdr tem))) (push (car tem) pre-loop-post-step-tests)) + (setq pre-loop-pseudo-steps (nconc pre-loop-pseudo-steps (loop-copylist* (cadr tem)))) + (unless (loop-tequal (car *loop-source-code*) :and) + (setq *loop-before-loop* (list* (loop-make-desetq pre-loop-pseudo-steps) + (make-endtest pre-loop-post-step-tests) + (loop-make-psetq pre-loop-steps) + (make-endtest pre-loop-pre-step-tests) + *loop-before-loop*) + *loop-after-body* (list* (loop-make-desetq pseudo-steps) + (make-endtest post-step-tests) + (loop-make-psetq steps) + (make-endtest pre-step-tests) + *loop-after-body*)) + (loop-bind-block) + (return nil)) + (loop-pop-source) ; flush the "AND" + (when (and (not (loop-universe-implicit-for-required *loop-universe*)) + (setq tem (loop-lookup-keyword + (car *loop-source-code*) + (loop-universe-iteration-keywords *loop-universe*)))) + ;;Latest ANSI clarification is that the FOR/AS after the AND must NOT be supplied. + (loop-pop-source) + (setq entry tem))))) + + +;;;; Main Iteration Drivers + + +;FOR variable keyword ..args.. +(defun loop-do-for () + (let* ((var (or (loop-pop-source) (loop-gentemp 'loop-do-for-anon-))) + (data-type (loop-optional-type var)) + (keyword (loop-pop-source)) + (first-arg nil) + (tem nil)) + (setq first-arg (loop-get-form)) + (unless (and (symbolp keyword) + (setq tem (loop-lookup-keyword + keyword + (loop-universe-for-keywords *loop-universe*)))) + (loop-error "~S is an unknown keyword in FOR or AS clause in LOOP." keyword)) + (apply (car tem) var first-arg data-type (cdr tem)))) + +(defun loop-do-repeat () + (loop-disallow-conditional :repeat) + (let ((form (loop-get-form)) + (type 'real)) + (let ((var (loop-make-variable (loop-gentemp) form type))) + (push `(when (minusp (decf ,var)) (go end-loop)) *loop-before-loop*) + (push `(when (minusp (decf ,var)) (go end-loop)) *loop-after-body*) + ;; FIXME: What should + ;; (loop count t into a + ;; repeat 3 + ;; count t into b + ;; finally (return (list a b))) + ;; return: (3 3) or (4 3)? PUSHes above are for the former + ;; variant, L-P-B below for the latter. + #+nil (loop-pseudo-body `(when (minusp (decf ,var)) (go end-loop)))))) + +(defun loop-when-it-variable () + (or *loop-when-it-variable* + (setq *loop-when-it-variable* + (loop-make-variable (loop-gentemp 'loop-it-) nil nil)))) + + +;;;; Various FOR/AS Subdispatches + + +;;;ANSI "FOR x = y [THEN z]" is sort of like the old Genera one when the THEN +;;; is omitted (other than being more stringent in its placement), and like +;;; the old "FOR x FIRST y THEN z" when the THEN is present. I.e., the first +;;; initialization occurs in the loop body (first-step), not in the variable binding +;;; phase. +(defun loop-ansi-for-equals (var val data-type) + (loop-make-iteration-variable var nil data-type) + (cond ((loop-tequal (car *loop-source-code*) :then) + ;;Then we are the same as "FOR x FIRST y THEN z". + (loop-pop-source) + `(() (,var ,(loop-get-form)) () () + () (,var ,val) () ())) + (t ;;We are the same as "FOR x = y". + ;; Let me document here what this is returning. Look at + ;; loop-hack-iteration for more info. But anyway, we return a list of + ;; 8 items, in this order: PRE-STEP-TESTS, STEPS, POST-STEP-TESTS, + ;; PSEUDO-STEPS, PRE-LOOP-PRE-STEP-TESTS, PRE-LOOP-STEPS, + ;; PRE-LOOP-POST-STEP-TESTS, PRE-LOOP-PSEUDO-STEPS. (We should add + ;; something to make it easier to figure out what these args are!) + ;; + ;; For a "FOR x = y" clause without the THEN, we want the STEPS item to + ;; step the variable VAR with the value VAL. This gets placed in the + ;; body of the loop. The original code just did that. It seems that + ;; the STEPS form is placed in *loop-before-loop* and in + ;; *loop-after-loop*. Loop optimization would then see the same form + ;; in both, and move them into the beginning of body. This is ok, + ;; except that if there are :initially forms that were placed into the + ;; loop prologue, the :initially forms might refer to incorrectly + ;; initialized variables, because the optimizer moved STEPS from from + ;; *loop-before-loop* into the body. + ;; + ;; To solve this, we add a PRE-LOOP-PSEUDO-STEP form that is identical + ;; to the STEPS form. This gets placed in *loop-before-loop*. But + ;; this won't match any *loop-after-loop* form, so it won't get moved, + ;; and we maintain the proper sequencing such that the + ;; PRE-LOOP-PSEUDO-STEP form is in *loop-before-loop*, before any + ;; :initially clauses that might refer to this. So all is well. Whew. + ;; + ;; I hope this doesn't break anything else. + `(() (,var ,val) () () + () () () (,var ,val)) + ))) + + +(defun loop-for-across (var val data-type) + (loop-make-iteration-variable var nil data-type) + (let ((vector-var (loop-gentemp 'loop-across-vector-)) + (index-var (loop-gentemp 'loop-across-index-))) + (multiple-value-bind (vector-form constantp vector-value) + (loop-constant-fold-if-possible val 'vector) + (loop-make-variable + vector-var vector-form + (if (and (consp vector-form) (eq (car vector-form) 'the)) + (cadr vector-form) + 'vector)) + #+Genera (push `(system:array-register ,vector-var) *loop-declarations*) + (loop-make-variable index-var 0 'fixnum) + (let* ((length 0) + (length-form (cond ((not constantp) + (let ((v (loop-gentemp 'loop-across-limit-))) + ;; This used to just push the length + ;; computation into the prologue code. I + ;; (rtoy) don't think that's right, + ;; especially since the prologue is supposed + ;; to happen AFTER other initializations. + ;; So, this puts the computation in + ;; *loop-before-body*. We need a matching + ;; entry for *loop-after-body*, so stuff a + ;; NIL there. + (push `(setq ,v (length ,vector-var)) *loop-before-loop*) + (push nil *loop-after-body*) + (loop-make-variable v 0 'fixnum))) + (t (setq length (length vector-value))))) + (first-test `(>= ,index-var ,length-form)) + (other-test first-test) + (step `(,var (aref ,vector-var ,index-var))) + (pstep `(,index-var (1+ ,index-var)))) + (declare (fixnum length)) + (when constantp + (setq first-test (= length 0)) + (when (<= length 1) + (setq other-test t))) + `(,other-test ,step () ,pstep + ,@(and (not (eq first-test other-test)) `(,first-test ,step () ,pstep))))))) + + + +;;;; List Iteration + + +(defun loop-list-step (listvar) + ;;We are not equipped to analyze whether 'FOO is the same as #'FOO here in any + ;; sensible fashion, so let's give an obnoxious warning whenever 'FOO is used + ;; as the stepping function. + ;;While a Discerning Compiler may deal intelligently with (funcall 'foo ...), not + ;; recognizing FOO may defeat some LOOP optimizations. + (let ((stepper (cond ((loop-tequal (car *loop-source-code*) :by) + (loop-pop-source) + (loop-get-form)) + (t '(function cdr))))) + (cond ((and (consp stepper) (eq (car stepper) 'quote)) + (loop-warn "Use of QUOTE around stepping function in LOOP will be left verbatim.") + (values `(funcall ,stepper ,listvar) nil)) + ((and (consp stepper) (eq (car stepper) 'function)) + (values (list (cadr stepper) listvar) (cadr stepper))) + (t (values `(funcall ,(loop-make-variable (loop-gentemp 'loop-fn-) stepper 'function) + ,listvar) + nil))))) + + +(defun loop-for-on (var val data-type) + (multiple-value-bind (list constantp list-value) (loop-constant-fold-if-possible val) + (let ((listvar var)) + (cond ((and var (symbolp var)) (loop-make-iteration-variable var list data-type)) + (t (loop-make-variable (setq listvar (loop-gentemp)) list 't) + (loop-make-iteration-variable var nil data-type))) + (multiple-value-bind (list-step step-function) (loop-list-step listvar) + (declare #+(and (not LOOP-Prefer-POP) (not CLOE)) (ignore step-function)) + ;;@@@@ The CLOE problem above has to do with bug in macroexpansion of multiple-value-bind. + (let* ((first-endtest + (hide-variable-reference + (eq var listvar) + listvar + ;; the following should use `atom' instead of `endp', per + ;; [bug2428] + `(atom ,listvar))) + (other-endtest first-endtest)) + (when (and constantp (listp list-value)) + (setq first-endtest (null list-value))) + (cond ((eq var listvar) + ;;Contour of the loop is different because we use the user's variable... + `(() (,listvar ,(hide-variable-reference t listvar list-step)) ,other-endtest + () () () ,first-endtest ())) + #+LOOP-Prefer-POP + ((and step-function + (let ((n (cdr (assoc step-function '((cdr . 1) (cddr . 2) + (cdddr . 3) (cddddr . 4)))))) + (and n (do ((l var (cdr l)) (i 0 (1+ i))) + ((atom l) (and (null l) (= i n))) + (declare (fixnum i)))))) + (let ((step (mapcan #'(lambda (x) (list x `(pop ,listvar))) var))) + `(,other-endtest () () ,step ,first-endtest () () ,step))) + (t (let ((step `(,var ,listvar)) (pseudo `(,listvar ,list-step))) + `(,other-endtest ,step () ,pseudo + ,@(and (not (eq first-endtest other-endtest)) + `(,first-endtest ,step () ,pseudo))))))))))) + + +(defun loop-for-in (var val data-type) + (multiple-value-bind (list constantp list-value) (loop-constant-fold-if-possible val) + (let ((listvar (loop-gentemp 'loop-list-))) + (loop-make-iteration-variable var nil data-type) + (loop-make-variable listvar list 'list) + (multiple-value-bind (list-step step-function) (loop-list-step listvar) + #-LOOP-Prefer-POP (declare (ignore step-function)) + (let* ((first-endtest `(endp ,listvar)) + (other-endtest first-endtest) + (step `(,var (car ,listvar))) + (pseudo-step `(,listvar ,list-step))) + (when (and constantp (listp list-value)) + (setq first-endtest (null list-value))) + #+LOOP-Prefer-POP (when (eq step-function 'cdr) + (setq step `(,var (pop ,listvar)) pseudo-step nil)) + `(,other-endtest ,step () ,pseudo-step + ,@(and (not (eq first-endtest other-endtest)) + `(,first-endtest ,step () ,pseudo-step)))))))) + + +;;;; Iteration Paths + + +(defstruct (loop-path + (:copier nil) + (:predicate nil)) + names + preposition-groups + inclusive-permitted + function + user-data) + + +(eval-when (:compile-toplevel :load-toplevel :execute) + (defun add-loop-path (names function universe &key preposition-groups inclusive-permitted user-data) + (unless (listp names) (setq names (list names))) + ;; Can't do this due to CLOS bootstrapping problems. + #-(or Genera (and CLOE Source-Bootstrap)) (check-type universe loop-universe) + (let ((ht (loop-universe-path-keywords universe)) + (lp (make-loop-path + :names (mapcar #'symbol-name names) + :function function + :user-data user-data + :preposition-groups (mapcar #'(lambda (x) (if (listp x) x (list x))) preposition-groups) + :inclusive-permitted inclusive-permitted))) + (dolist (name names) (setf (gethash (symbol-name name) ht) lp)) + lp))) + + +;;; Note: path functions are allowed to use loop-make-variable, hack +;;; the prologue, etc. +(defun loop-for-being (var val data-type) + ;; FOR var BEING each/the pathname prep-phrases using-stuff... + ;; each/the = EACH or THE. Not clear if it is optional, so I guess we'll warn. + (let ((path nil) + (data nil) + (inclusive nil) + (stuff nil) + (initial-prepositions nil)) + (cond ((loop-tmember val '(:each :the)) (setq path (loop-pop-source))) + ((loop-tequal (car *loop-source-code*) :and) + (loop-pop-source) + (setq inclusive t) + (unless (loop-tmember (car *loop-source-code*) '(:its :each :his :her)) + (loop-error "~S found where ITS or EACH expected in LOOP iteration path syntax." + (car *loop-source-code*))) + (loop-pop-source) + (setq path (loop-pop-source)) + (setq initial-prepositions `((:in ,val)))) + (t (loop-error "Unrecognizable LOOP iteration path syntax. Missing EACH or THE?"))) + (cond ((not (symbolp path)) + (loop-error "~S found where a LOOP iteration path name was expected." path)) + ((not (setq data (loop-lookup-keyword path (loop-universe-path-keywords *loop-universe*)))) + (loop-error "~S is not the name of a LOOP iteration path." path)) + ((and inclusive (not (loop-path-inclusive-permitted data))) + (loop-error "\"Inclusive\" iteration is not possible with the ~S LOOP iteration path." path))) + (let ((fun (loop-path-function data)) + (preps (nconc initial-prepositions + (loop-collect-prepositional-phrases (loop-path-preposition-groups data) t))) + (user-data (loop-path-user-data data))) + (when (symbolp fun) (setq fun (symbol-function fun))) + (setq stuff (if inclusive + (apply fun var data-type preps :inclusive t user-data) + (apply fun var data-type preps user-data)))) + (when *loop-named-variables* + (loop-error "Unused USING variables: ~S." *loop-named-variables*)) + ;; STUFF is now (bindings prologue-forms . stuff-to-pass-back). Protect the system from the user + ;; and the user from himself. + (unless (member (length stuff) '(6 10)) + (loop-error "Value passed back by LOOP iteration path function for path ~S has invalid length." + path)) + (do ((l (car stuff) (cdr l)) (x)) ((null l)) + (if (atom (setq x (car l))) + (loop-make-iteration-variable x nil nil) + (loop-make-iteration-variable (car x) (cadr x) (caddr x)))) + (setq *loop-prologue* (nconc (reverse (cadr stuff)) *loop-prologue*)) + (cddr stuff))) + + + +;;;INTERFACE: Lucid, exported. +;;; i.e., this is part of our extended ansi-loop interface. +(defun named-variable (name) + (let ((tem (loop-tassoc name *loop-named-variables*))) + (declare (list tem)) + (cond ((null tem) (values (loop-gentemp) nil)) + (t (setq *loop-named-variables* (delete tem *loop-named-variables*)) + (values (cdr tem) t))))) + + +(defun loop-collect-prepositional-phrases (preposition-groups &optional USING-allowed initial-phrases) + (flet ((in-group-p (x group) (car (loop-tmember x group)))) + (do ((token nil) + (prepositional-phrases initial-phrases) + (this-group nil nil) + (this-prep nil nil) + (disallowed-prepositions + (mapcan #'(lambda (x) + (loop-copylist* + (find (car x) preposition-groups :test #'in-group-p))) + initial-phrases)) + (used-prepositions (mapcar #'car initial-phrases))) + ((null *loop-source-code*) (nreverse prepositional-phrases)) + (declare (symbol this-prep)) + (setq token (car *loop-source-code*)) + (dolist (group preposition-groups) + (when (setq this-prep (in-group-p token group)) + (return (setq this-group group)))) + (cond (this-group + (when (member this-prep disallowed-prepositions) + (loop-error + (if (member this-prep used-prepositions) + "A ~S prepositional phrase occurs multiply for some LOOP clause." + "Preposition ~S used when some other preposition has subsumed it.") + token)) + (setq used-prepositions (if (listp this-group) + (append this-group used-prepositions) + (cons this-group used-prepositions))) + (loop-pop-source) + (push (list this-prep (loop-get-form)) prepositional-phrases)) + ((and USING-allowed (loop-tequal token 'using)) + (loop-pop-source) + (do ((z (loop-pop-source) (loop-pop-source)) (tem)) (nil) + (when (cadr z) + (if (setq tem (loop-tassoc (car z) *loop-named-variables*)) + (loop-error + "The variable substitution for ~S occurs twice in a USING phrase,~@ + with ~S and ~S." + (car z) (cadr z) (cadr tem)) + (push (cons (car z) (cadr z)) *loop-named-variables*))) + (when (or (null *loop-source-code*) (symbolp (car *loop-source-code*))) + (return nil)))) + (t (return (nreverse prepositional-phrases))))))) + + +;;;; Master Sequencer Function + + +(defun loop-sequencer (indexv indexv-type indexv-user-specified-p + variable variable-type + sequence-variable sequence-type + step-hack default-top + prep-phrases) + (let ((endform nil) ;Form (constant or variable) with limit value. + (sequencep nil) ;T if sequence arg has been provided. + (testfn nil) ;endtest function + (test nil) ;endtest form. + (stepby (1+ (or (loop-typed-init indexv-type) 0))) ;Our increment. + (stepby-constantp t) + (step nil) ;step form. + (dir nil) ;Direction of stepping: NIL, :UP, :DOWN. + (inclusive-iteration nil) ;T if include last index. + (start-given nil) ;T when prep phrase has specified start + (start-value nil) + (start-constantp nil) + (limit-given nil) ;T when prep phrase has specified end + (limit-constantp nil) + (limit-value nil) + ) + (when variable (loop-make-iteration-variable variable nil variable-type)) + (do ((l prep-phrases (cdr l)) (prep) (form) (odir)) ((null l)) + (setq prep (caar l) form (cadar l)) + (case prep + ((:of :in) + (setq sequencep t) + (loop-make-variable sequence-variable form sequence-type)) + ((:from :downfrom :upfrom) + (setq start-given t) + (cond ((eq prep :downfrom) (setq dir ':down)) + ((eq prep :upfrom) (setq dir ':up))) + (multiple-value-setq (form start-constantp start-value) + (loop-constant-fold-if-possible form indexv-type)) + (loop-make-iteration-variable indexv form indexv-type)) + ((:upto :to :downto :above :below) + (cond ((loop-tequal prep :upto) (setq inclusive-iteration (setq dir ':up))) + ((loop-tequal prep :to) (setq inclusive-iteration t)) + ((loop-tequal prep :downto) (setq inclusive-iteration (setq dir ':down))) + ((loop-tequal prep :above) (setq dir ':down)) + ((loop-tequal prep :below) (setq dir ':up))) + (setq limit-given t) + (multiple-value-setq (form limit-constantp limit-value) + (loop-constant-fold-if-possible form indexv-type)) + (setq endform (if limit-constantp + `',limit-value + (loop-make-variable + (loop-gentemp 'loop-limit-) form indexv-type)))) + (:by + (multiple-value-setq (form stepby-constantp stepby) + (loop-constant-fold-if-possible form indexv-type)) + (unless stepby-constantp + (loop-make-variable (setq stepby (loop-gentemp 'loop-step-by-)) form indexv-type))) + (t (loop-error + "~S invalid preposition in sequencing or sequence path.~@ + Invalid prepositions specified in iteration path descriptor or something?" + prep))) + (when (and odir dir (not (eq dir odir))) + (loop-error "Conflicting stepping directions in LOOP sequencing path")) + (setq odir dir)) + (when (and sequence-variable (not sequencep)) + (loop-error "Missing OF or IN phrase in sequence path")) + ;; Now fill in the defaults. + (unless start-given + (loop-make-iteration-variable + indexv + (setq start-constantp t start-value (or (loop-typed-init indexv-type) 0)) + indexv-type)) + (cond ((member dir '(nil :up)) + (when (or limit-given default-top) + (unless limit-given + (loop-make-variable (setq endform (loop-gentemp 'loop-seq-limit-)) + nil indexv-type) + (push `(setq ,endform ,default-top) *loop-prologue*)) + (setq testfn (if inclusive-iteration '> '>=))) + (setq step (if (eql stepby 1) `(1+ ,indexv) `(+ ,indexv ,stepby)))) + (t (unless start-given + (unless default-top + (loop-error "Don't know where to start stepping.")) + (push `(setq ,indexv (1- ,default-top)) *loop-prologue*)) + (when (and default-top (not endform)) + (setq endform (loop-typed-init indexv-type) inclusive-iteration t)) + (when endform (setq testfn (if inclusive-iteration '< '<=))) + (setq step (if (eql stepby 1) `(1- ,indexv) `(- ,indexv ,stepby))))) + (when testfn (setq test (hide-variable-reference t indexv `(,testfn ,indexv ,endform)))) + (when step-hack + (setq step-hack `(,variable ,(hide-variable-reference indexv-user-specified-p indexv step-hack)))) + (let ((first-test test) (remaining-tests test)) + (when (and stepby-constantp start-constantp limit-constantp) + (when (setq first-test (funcall (symbol-function testfn) start-value limit-value)) + (setq remaining-tests t))) + `(() (,indexv ,(hide-variable-reference t indexv step)) ,remaining-tests ,step-hack + () () ,first-test ,step-hack)))) + + +;;;; Interfaces to the Master Sequencer + + + +(defun loop-for-arithmetic (var val data-type kwd) + (loop-sequencer + var (loop-check-data-type data-type 'number) t + nil nil nil nil nil nil + (loop-collect-prepositional-phrases + '((:from :upfrom :downfrom) (:to :upto :downto :above :below) (:by)) + nil (list (list kwd val))))) + + +(defun loop-sequence-elements-path (variable data-type prep-phrases + &key fetch-function size-function sequence-type element-type) + (multiple-value-bind (indexv indexv-user-specified-p) (named-variable 'index) + (let ((sequencev (named-variable 'sequence))) + #+Genera (when (and sequencev + (symbolp sequencev) + sequence-type + (subtypep sequence-type 'vector) + (not (member (the symbol sequencev) *loop-nodeclare*))) + (push `(sys:array-register ,sequencev) *loop-declarations*)) + (list* nil nil ; dummy bindings and prologue + (loop-sequencer + indexv 'fixnum indexv-user-specified-p + variable (or data-type element-type) + sequencev sequence-type + `(,fetch-function ,sequencev ,indexv) `(,size-function ,sequencev) + prep-phrases))))) + + +;;;; Builtin LOOP Iteration Paths + + +#|| +(loop for v being the hash-values of ht do (print v)) +(loop for k being the hash-keys of ht do (print k)) +(loop for v being the hash-values of ht using (hash-key k) do (print (list k v))) +(loop for k being the hash-keys of ht using (hash-value v) do (print (list k v))) +||# + +(defun loop-hash-table-iteration-path (variable data-type prep-phrases &key which) + (check-type which (member hash-key hash-value)) + (cond ((or (cdr prep-phrases) (not (member (caar prep-phrases) '(:in :of)))) + (loop-error "Too many prepositions!")) + ((null prep-phrases) (loop-error "Missing OF or IN in ~S iteration path."))) + (let ((ht-var (loop-gentemp 'loop-hashtab-)) + (next-fn (loop-gentemp 'loop-hashtab-next-)) + (dummy-predicate-var nil) + (post-steps nil)) + (multiple-value-bind (other-var other-p) + (named-variable (if (eq which 'hash-key) 'hash-value 'hash-key)) + ;;@@@@ named-variable returns a second value of T if the name was actually + ;; specified, so clever code can throw away the gensym'ed up variable if + ;; it isn't really needed. + ;;The following is for those implementations in which we cannot put dummy NILs + ;; into multiple-value-setq variable lists. + #-Genera (setq other-p t + dummy-predicate-var (loop-when-it-variable)) + (let* ((key-var nil) + (val-var nil) + (temp-val-var (loop-gentemp 'loop-hash-val-temp-)) + (temp-key-var (loop-gentemp 'loop-hash-key-temp-)) + (temp-predicate-var (loop-gentemp 'loop-hash-predicate-var-)) + (variable (or variable (loop-gentemp))) + (bindings `((,variable nil ,data-type) + (,ht-var ,(cadar prep-phrases)) + ,@(and other-p other-var `((,other-var nil)))))) + (if (eq which 'hash-key) + (setq key-var variable val-var (and other-p other-var)) + (setq key-var (and other-p other-var) val-var variable)) + (push `(with-hash-table-iterator (,next-fn ,ht-var)) *loop-wrappers*) + (when (consp key-var) + (setq post-steps `(,key-var ,(setq key-var (loop-gentemp 'loop-hash-key-temp-)) + ,@post-steps)) + (push `(,key-var nil) bindings)) + (when (consp val-var) + (setq post-steps `(,val-var ,(setq val-var (loop-gentemp 'loop-hash-val-temp-)) + ,@post-steps)) + (push `(,val-var nil) bindings)) + `(,bindings ;bindings + () ;prologue + () ;pre-test + () ;parallel steps + (not + (multiple-value-bind (,temp-predicate-var ,temp-key-var ,temp-val-var) + (,next-fn) + ;; We use M-V-BIND instead of M-V-SETQ because we only + ;; want to assign values to the key and val vars when we + ;; are in the hash table. When we reach the end, + ;; TEMP-PREDICATE-VAR is NIL, and so are temp-key-var and + ;; temp-val-var. This might break any type declarations + ;; on the key and val vars. + (when ,temp-predicate-var + (setq ,val-var ,temp-val-var) + (setq ,key-var ,temp-key-var)) + (setq ,dummy-predicate-var ,temp-predicate-var) + )) ;post-test + ,post-steps))))) + + +(defun loop-package-symbols-iteration-path (variable data-type prep-phrases &key symbol-types) + (cond ((and prep-phrases (cdr prep-phrases)) + (loop-error "Too many prepositions!")) + ((and prep-phrases (not (member (caar prep-phrases) '(:in :of)))) + (loop-error "Unknow preposition ~S" (caar prep-phrases)))) + (unless (symbolp variable) + (loop-error "Destructuring is not valid for package symbol iteration.")) + (let ((pkg-var (loop-gentemp 'loop-pkgsym-)) + (next-fn (loop-gentemp 'loop-pkgsym-next-)) + (variable (or variable (loop-gentemp))) + (pkg (or (cadar prep-phrases) '*package*))) + (push `(with-package-iterator (,next-fn ,pkg-var ,@symbol-types)) *loop-wrappers*) + `(((,variable nil ,data-type) (,pkg-var ,pkg)) + () + () + () + (not (multiple-value-setq (,(progn + ;;@@@@ If an implementation can get away without actually + ;; using a variable here, so much the better. + #+Genera NIL + #-Genera (loop-when-it-variable)) + ,variable) + (,next-fn))) + ()))) + +;;;; ANSI Loop + +(eval-when (:compile-toplevel :load-toplevel :execute) + + (defun make-ansi-loop-universe (extended-p) + (let ((w (make-standard-loop-universe + :keywords `((named (loop-do-named)) + (initially (loop-do-initially)) + (finally (loop-do-finally)) + (do (loop-do-do)) + (doing (loop-do-do)) + (return (loop-do-return)) + (collect (loop-list-collection list)) + (collecting (loop-list-collection list)) + (append (loop-list-collection append)) + (appending (loop-list-collection append)) + (nconc (loop-list-collection nconc)) + (nconcing (loop-list-collection nconc)) + (count (loop-sum-collection count ,*loop-real-data-type* fixnum)) + (counting (loop-sum-collection count ,*loop-real-data-type* fixnum)) + (sum (loop-sum-collection sum number number)) + (summing (loop-sum-collection sum number number)) + (maximize (loop-maxmin-collection max)) + (minimize (loop-maxmin-collection min)) + (maximizing (loop-maxmin-collection max)) + (minimizing (loop-maxmin-collection min)) + (always (loop-do-always t nil)) ; Normal, do always + (never (loop-do-always t t)) ; Negate the test on always. + (thereis (loop-do-thereis t)) + (while (loop-do-while nil :while)) ; Normal, do while + (until (loop-do-while t :until)) ; Negate the test on while + (when (loop-do-if when nil)) ; Normal, do when + (if (loop-do-if if nil)) ; synonymous + (unless (loop-do-if unless t)) ; Negate the test on when + (with (loop-do-with)) + (repeat (loop-do-repeat))) + :for-keywords '((= (loop-ansi-for-equals)) + (across (loop-for-across)) + (in (loop-for-in)) + (on (loop-for-on)) + (from (loop-for-arithmetic :from)) + (downfrom (loop-for-arithmetic :downfrom)) + (upfrom (loop-for-arithmetic :upfrom)) + (below (loop-for-arithmetic :below)) + (above (loop-for-arithmetic :above)) + (to (loop-for-arithmetic :to)) + (upto (loop-for-arithmetic :upto)) + (downto (loop-for-arithmetic :downto)) + (by (loop-for-arithmetic :by)) + (being (loop-for-being))) + :iteration-keywords '((for (loop-do-for)) + (as (loop-do-for))) + :type-symbols '(array atom bignum bit bit-vector character compiled-function + complex cons double-float fixnum float + function hash-table integer keyword list long-float + nil null number package pathname random-state + ratio rational readtable sequence short-float + simple-array simple-bit-vector simple-string + simple-vector single-float standard-char + stream string base-char + symbol t vector) + :type-keywords nil + :ansi (if extended-p :extended t)))) + (add-loop-path '(hash-key hash-keys) 'loop-hash-table-iteration-path w + :preposition-groups '((:of :in)) + :inclusive-permitted nil + :user-data '(:which hash-key)) + (add-loop-path '(hash-value hash-values) 'loop-hash-table-iteration-path w + :preposition-groups '((:of :in)) + :inclusive-permitted nil + :user-data '(:which hash-value)) + (add-loop-path '(symbol symbols) 'loop-package-symbols-iteration-path w + :preposition-groups '((:of :in)) + :inclusive-permitted nil + :user-data '(:symbol-types (:internal :external :inherited))) + (add-loop-path '(external-symbol external-symbols) 'loop-package-symbols-iteration-path w + :preposition-groups '((:of :in)) + :inclusive-permitted nil + :user-data '(:symbol-types (:external))) + (add-loop-path '(present-symbol present-symbols) 'loop-package-symbols-iteration-path w + :preposition-groups '((:of :in)) + :inclusive-permitted nil + :user-data '(:symbol-types (:internal :external))) + w)) + + + (defparameter *loop-ansi-universe* + (make-ansi-loop-universe nil)) + + (defun loop-standard-expansion (keywords-and-forms environment universe) + (if (and keywords-and-forms (symbolp (car keywords-and-forms))) + (loop-translate keywords-and-forms environment universe) + (let ((tag (gensym))) + `(block nil (tagbody ,tag (progn ,@keywords-and-forms) (go ,tag)))))) + + ) ;; eval-when + + +;;;INTERFACE: ANSI +(defmacro loop (&environment env &rest keywords-and-forms) + #+Genera (declare (compiler:do-not-record-macroexpansions) + (zwei:indentation . zwei:indent-loop)) + (loop-standard-expansion keywords-and-forms env *loop-ansi-universe*)) + +#+allegro +(defun excl::complex-loop-expander (body env) + (loop-standard-expansion body env *loop-ansi-universe*)) + +;; Replace the CL::LOOP macro with this macro for use with CLSQL +;; LOOP extensions +#+clisp +(eval-when (:compile-toplevel :load-toplevel :execute) + (shadowing-import '(loop loop-finish) (find-package "COMMON-LISP")) + (setf (ext:package-lock (find-package "COMMON-LISP")) t)) + |