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;;; -*- Mode: LISP; Package: ANSI-LOOP; Syntax: Common-lisp; Base: 10; Lowercase:T -*-
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;;;> Portions of LOOP are Copyright (c) 1986 by the Massachusetts Institute of Technology.
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;;;> All Rights Reserved.
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;;;> Permission to use, copy, modify and distribute this software and its
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;;;> documentation for any purpose and without fee is hereby granted,
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;;;> provided that the M.I.T. copyright notice appear in all copies and that
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;;;> both that copyright notice and this permission notice appear in
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;;;> supporting documentation. The names "M.I.T." and "Massachusetts
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;;;> Institute of Technology" may not be used in advertising or publicity
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;;;> pertaining to distribution of the software without specific, written
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;;;> prior permission. Notice must be given in supporting documentation that
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;;;> copying distribution is by permission of M.I.T. M.I.T. makes no
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;;;> representations about the suitability of this software for any purpose.
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;;;> It is provided "as is" without express or implied warranty.
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;;;> Massachusetts Institute of Technology
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;;;> 77 Massachusetts Avenue
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;;;> Cambridge, Massachusetts 02139
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;;;> United States of America
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;;;> Portions of LOOP are Copyright (c) 1989, 1990, 1991, 1992 by Symbolics, Inc.
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;;;> All Rights Reserved.
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;;;> Permission to use, copy, modify and distribute this software and its
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;;;> documentation for any purpose and without fee is hereby granted,
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;;;> provided that the Symbolics copyright notice appear in all copies and
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;;;> that both that copyright notice and this permission notice appear in
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;;;> supporting documentation. The name "Symbolics" may not be used in
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;;;> advertising or publicity pertaining to distribution of the software
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;;;> without specific, written prior permission. Notice must be given in
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;;;> supporting documentation that copying distribution is by permission of
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;;;> Symbolics. Symbolics makes no representations about the suitability of
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;;;> this software for any purpose. It is provided "as is" without express
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;;;> or implied warranty.
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;;;> Symbolics, CLOE Runtime, and Minima are trademarks, and CLOE, Genera,
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;;;> and Zetalisp are registered trademarks of Symbolics, Inc.
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;;;> 8 New England Executive Park, East
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;;;> Burlington, Massachusetts 01803
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;;;> United States of America
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;; $aclHeader: loop.cl,v 1.5 91/12/04 01:13:48 cox acl4_1 $
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"$Header: /cvsroot/gcl/gcl/mod/gcl_loop.lsp,v 1.1 2003/09/23 20:30:25 camm Exp $")
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;;;; LOOP Iteration Macro
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(in-package :ansi-loop)
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(export '(loop loop-finish))
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#+Cloe-Runtime ;Don't ask.
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(car (push "%Z% %M% %I% %E% %U%" system::*module-identifications*))
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;;; The LOOP iteration macro is one of a number of pieces of code
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;;; originally developed at MIT for which free distribution has been
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;;; permitted, as long as the code is not sold for profit, and as long
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;;; as notification of MIT's interest in the code is preserved.
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;;; This version of LOOP, which is almost entirely rewritten both as
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;;; clean-up and to conform with the ANSI Lisp LOOP standard, started
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;;; life as MIT LOOP version 829 (which was a part of NIL, possibly
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;;; A "light revision" was performed by me (Glenn Burke) while at
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;;; Palladian Software in April 1986, to make the code run in Common
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;;; Lisp. This revision was informally distributed to a number of
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;;; people, and was sort of the "MIT" version of LOOP for running in
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;;; A later more drastic revision was performed at Palladian perhaps a
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;;; year later. This version was more thoroughly Common Lisp in style,
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;;; with a few miscellaneous internal improvements and extensions. I
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;;; have lost track of this source, apparently never having moved it to
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;;; the MIT distribution point. I do not remember if it was ever
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;;; This revision for the ANSI standard is based on the code of my April
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;;; 1986 version, with almost everything redesigned and/or rewritten.
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;;; The design of this LOOP is intended to permit, using mostly the same
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;;; kernel of code, up to three different "loop" macros:
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;;; (1) The unextended, unextensible ANSI standard LOOP;
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;;; (2) A clean "superset" extension of the ANSI LOOP which provides
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;;; functionality similar to that of the old LOOP, but "in the style of"
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;;; the ANSI LOOP. For instance, user-definable iteration paths, with a
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;;; somewhat cleaned-up interface.
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;;; (3) Extensions provided in another file which can make this LOOP
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;;; kernel behave largely compatibly with the Genera-vintage LOOP macro,
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;;; with only a small addition of code (instead of two whole, separate,
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;;; Each of the above three LOOP variations can coexist in the same LISP
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;;;; Miscellaneous Environment Things
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;;;@@@@The LOOP-Prefer-POP feature makes LOOP generate code which "prefers" to use POP or
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;;; its obvious expansion (prog1 (car x) (setq x (cdr x))). Usually this involves
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;;; shifting fenceposts in an iteration or series of carcdr operations. This is
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;;; primarily recognized in the list iterators (FOR .. {IN,ON}), and LOOP's
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;;; destructuring setq code.
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(eval-when (compile load eval)
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#+(or Genera Minima) (pushnew :LOOP-Prefer-POP *features*)
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;;; The uses of this macro are retained in the CL version of loop, in
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;;; case they are needed in a particular implementation. Originally
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;;; dating from the use of the Zetalisp COPYLIST* function, this is used
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;;; in situations where, were cdr-coding in use, having cdr-NIL at the
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;;; end of the list might be suboptimal because the end of the list will
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;;; probably be RPLACDed and so cdr-normal should be used instead.
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(defmacro loop-copylist* (l)
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#+Genera `(lisp:copy-list ,l nil t) ; arglist = (list &optional area force-dotted)
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#-Genera `(copy-list ,l)
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(defvar *loop-gentemp*
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(defun loop-gentemp (&optional (pref 'loopvar-))
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(gensym (string pref))
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(defvar *loop-real-data-type* 'real)
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(defun loop-optimization-quantities (env)
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;;@@@@ The ANSI conditionalization here is for those lisps that implement
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;; DECLARATION-INFORMATION (from cleanup SYNTACTIC-ENVIRONMENT-ACCESS).
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;; It is really commentary on how this code could be written. I don't
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;; actually expect there to be an ANSI #+-conditional -- it should be
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;; replaced with the appropriate conditional name for your
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;; implementation/dialect.
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(declare #-ANSI (ignore env)
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#+Genera (values speed space safety compilation-speed debug))
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#+ANSI (let ((stuff (declaration-information 'optimize env)))
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(values (or (cdr (assoc 'speed stuff)) 1)
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(or (cdr (assoc 'space stuff)) 1)
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(or (cdr (assoc 'safety stuff)) 1)
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(or (cdr (assoc 'compilation-speed stuff)) 1)
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(or (cdr (assoc 'debug stuff)) 1)))
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#+CLOE-Runtime (values compiler::time compiler::space
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compiler::safety compiler::compilation-speed 1)
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#-(or ANSI CLOE-Runtime) (values 1 1 1 1 1))
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;;;@@@@ The following form takes a list of variables and a form which presumably
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;;; references those variables, and wraps it somehow so that the compiler does not
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;;; consider those variables have been referenced. The intent of this is that
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;;; iteration variables can be flagged as unused by the compiler, e.g. I in
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;;; (loop for i from 1 to 10 do (print t)), since we will tell it when a usage
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;;; of it is "invisible" or "not to be considered".
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;;;We implicitly assume that a setq does not count as a reference. That is, the
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;;; kind of form generated for the above loop construct to step I, simplified, is
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;;; `(SETQ I ,(HIDE-VARIABLE-REFERENCES '(I) '(1+ I))).
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(defun hide-variable-references (variable-list form)
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(declare #-Genera (ignore variable-list))
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#+Genera (if variable-list `(compiler:invisible-references ,variable-list ,form) form)
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;;;@@@@ The following function takes a flag, a variable, and a form which presumably
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;;; references that variable, and wraps it somehow so that the compiler does not
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;;; consider that variable to have been referenced. The intent of this is that
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;;; iteration variables can be flagged as unused by the compiler, e.g. I in
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;;; (loop for i from 1 to 10 do (print t)), since we will tell it when a usage
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;;; of it is "invisible" or "not to be considered".
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;;;We implicitly assume that a setq does not count as a reference. That is, the
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;;; kind of form generated for the above loop construct to step I, simplified, is
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;;; `(SETQ I ,(HIDE-VARIABLE-REFERENCES T 'I '(1+ I))).
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;;;Certain cases require that the "invisibility" of the reference be conditional upon
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;;; something. This occurs in cases of "named" variables (the USING clause). For instance,
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;;; we want IDX in (LOOP FOR E BEING THE VECTOR-ELEMENTS OF V USING (INDEX IDX) ...)
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;;; to be "invisible" when it is stepped, so that the user gets informed if IDX is
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;;; not referenced. However, if no USING clause is present, we definitely do not
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;;; want to be informed that some random gensym is not used.
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;;;It is easier for the caller to do this conditionally by passing a flag (which
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;;; happens to be the second value of NAMED-VARIABLE, q.v.) to this function than
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;;; for all callers to contain the conditional invisibility construction.
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(defun hide-variable-reference (really-hide variable form)
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(declare #-Genera (ignore really-hide variable))
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#+Genera (if (and really-hide variable (atom variable)) ;Punt on destructuring patterns
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`(compiler:invisible-references (,variable) ,form)
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;;;; List Collection Macrology
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(defmacro with-loop-list-collection-head ((head-var tail-var &optional user-head-var)
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#+LISPM (let ((head-place (or user-head-var head-var)))
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`(let* ((,head-place nil)
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,(hide-variable-reference
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user-head-var user-head-var
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`(progn #+Genera (scl:locf ,head-place)
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#-Genera (system:variable-location ,head-place)))))
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#-LISPM (let ((l (and user-head-var (list (list user-head-var nil)))))
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#+CLOE `(sys::with-stack-list* (,head-var nil nil)
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(let ((,tail-var ,head-var) ,@l)
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#-CLOE `(let* ((,head-var (list nil)) (,tail-var ,head-var) ,@l)
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(defmacro loop-collect-rplacd (&environment env
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(head-var tail-var &optional user-head-var) form)
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#+LISPM (ignore head-var user-head-var) ;use locatives, unconditionally update through the tail.
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(setq form (macroexpand form env))
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(flet ((cdr-wrap (form n)
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(do () ((<= n 4) (setq form `(,(case n
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(setq form `(cddddr ,form) n (- n 4)))))
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(let ((tail-form form) (ncdrs nil))
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;;Determine if the form being constructed is a list of known length.
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(cond ((eq (car form) 'list)
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(setq ncdrs (1- (length (cdr form))))
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;;@@@@ Because the last element is going to be RPLACDed,
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;; we don't want the cdr-coded implementations to use
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;; cdr-nil at the end (which would just force copying
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;; the whole list again).
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#+LISPM (setq tail-form `(list* ,@(cdr form) nil)))
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((member (car form) '(list* cons))
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(when (and (cddr form) (member (car (last form)) '(nil 'nil)))
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(setq ncdrs (- (length (cdr form)) 2))))))
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`(when (setf (cdr ,tail-var) ,tail-form)
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(setq ,tail-var (last (cdr ,tail-var)))))
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((< ncdrs 0) (return-from loop-collect-rplacd nil))
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;;@@@@ Here we have a choice of two idioms:
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;; (rplacd tail (setq tail tail-form))
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;; (setq tail (setf (cdr tail) tail-form)).
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;;Genera and most others I have seen do better with the former.
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`(rplacd ,tail-var (setq ,tail-var ,tail-form)))
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(t `(setq ,tail-var ,(cdr-wrap `(setf (cdr ,tail-var) ,tail-form)
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;;If not using locatives or something similar to update the user's
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;; head variable, we've got to set it... It's harmless to repeatedly set it
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;; unconditionally, and probably faster than checking.
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#-LISPM (when user-head-var
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(setq answer `(progn ,answer (setq ,user-head-var (cdr ,head-var)))))
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(defmacro loop-collect-answer (head-var &optional user-head-var)
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;;If we use locatives to get tail-updating to update the head var,
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;; then the head var itself contains the answer. Otherwise we
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#-LISPM `(cdr ,head-var))))
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;;;; Maximization Technology
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The basic idea of all this minimax randomness here is that we have to
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have constructed all uses of maximize and minimize to a particular
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"destination" before we can decide how to code them. The goal is to not
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have to have any kinds of flags, by knowing both that (1) the type is
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something which we can provide an initial minimum or maximum value for
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and (2) know that a MAXIMIZE and MINIMIZE are not being combined.
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SO, we have a datastructure which we annotate with all sorts of things,
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incrementally updating it as we generate loop body code, and then use
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a wrapper and internal macros to do the coding when the loop has been
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(defstruct (loop-minimax
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(:constructor make-loop-minimax-internal)
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(defvar *loop-minimax-type-infinities-alist*
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;;@@@@ This is the sort of value this should take on for a Lisp that has
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;; "eminently usable" infinities. n.b. there are neither constants nor
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;; printed representations for infinities defined by CL.
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;;@@@@ This grotesque read-from-string below is to help implementations
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;; which croak on the infinity character when it appears in a token, even
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;; conditionalized out.
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"((fixnum most-positive-fixnum most-negative-fixnum)
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(short-float +1s -1s)
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(single-float +1f -1f)
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(double-float +1d -1d)
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(long-float +1l -1l))")
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;;This is how the alist should look for a lisp that has no infinities. In
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;; that case, MOST-POSITIVE-x-FLOAT really IS the most positive.
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#+(or CLOE-Runtime Minima)
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'((fixnum most-positive-fixnum most-negative-fixnum)
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(short-float most-positive-short-float most-negative-short-float)
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(single-float most-positive-single-float most-negative-single-float)
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(double-float most-positive-double-float most-negative-double-float)
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(long-float most-positive-long-float most-negative-long-float))
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;; CMUCL has infinities so let's use them.
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'((fixnum most-positive-fixnum most-negative-fixnum)
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(short-float ext:single-float-positive-infinity ext:single-float-negative-infinity)
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(single-float ext:single-float-positive-infinity ext:single-float-negative-infinity)
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(double-float ext:double-float-positive-infinity ext:double-float-negative-infinity)
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(long-float ext:long-float-positive-infinity ext:long-float-negative-infinity))
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;; If we don't know, then we cannot provide "infinite" initial values for any of the
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#-(or Genera CLOE-Runtime Minima CMU)
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'((fixnum most-positive-fixnum most-negative-fixnum))
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(defun make-loop-minimax (answer-variable type)
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(let ((infinity-data (cdr (assoc type *loop-minimax-type-infinities-alist* :test #'subtypep))))
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(make-loop-minimax-internal
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:answer-variable answer-variable
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:temp-variable (loop-gentemp 'loop-maxmin-temp-)
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:flag-variable (and (not infinity-data) (loop-gentemp 'loop-maxmin-flag-))
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:infinity-data infinity-data)))
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(defun loop-note-minimax-operation (operation minimax)
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(pushnew (the symbol operation) (loop-minimax-operations minimax))
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(when (and (cdr (loop-minimax-operations minimax))
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(not (loop-minimax-flag-variable minimax)))
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(setf (loop-minimax-flag-variable minimax) (loop-gentemp 'loop-maxmin-flag-)))
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(defmacro with-minimax-value (lm &body body)
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(let ((init (loop-typed-init (loop-minimax-type lm)))
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(which (car (loop-minimax-operations lm)))
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(infinity-data (loop-minimax-infinity-data lm))
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(answer-var (loop-minimax-answer-variable lm))
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(temp-var (loop-minimax-temp-variable lm))
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(flag-var (loop-minimax-flag-variable lm))
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(type (loop-minimax-type lm)))
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`(let ((,answer-var ,init) (,temp-var ,init) (,flag-var nil))
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(declare (type ,type ,answer-var ,temp-var))
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`(let ((,answer-var ,(if (eq which 'min) (first infinity-data) (second infinity-data)))
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(declare (type ,type ,answer-var ,temp-var))
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(defmacro loop-accumulate-minimax-value (lm operation form)
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(let* ((answer-var (loop-minimax-answer-variable lm))
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(temp-var (loop-minimax-temp-variable lm))
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(flag-var (loop-minimax-flag-variable lm))
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(hide-variable-reference
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t (loop-minimax-answer-variable lm)
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,temp-var ,answer-var))))
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(setq ,temp-var ,form)
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(when ,(if flag-var `(or (not ,flag-var) ,test) test)
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(setq ,@(and flag-var `(,flag-var t))
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,answer-var ,temp-var)))))
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;;;; Loop Keyword Tables
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LOOP keyword tables are hash tables string keys and a test of EQUAL.
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The actual descriptive/dispatch structure used by LOOP is called a "loop
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universe" contains a few tables and parameterizations. The basic idea is
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that we can provide a non-extensible ANSI-compatible loop environment,
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an extensible ANSI-superset loop environment, and (for such environments
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as CLOE) one which is "sufficiently close" to the old Genera-vintage
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LOOP for use by old user programs without requiring all of the old LOOP
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;;;Compare two "tokens". The first is the frob out of *LOOP-SOURCE-CODE*,
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;;; the second a symbol to check against.
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(defun loop-tequal (x1 x2)
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(and (symbolp x1) (string= x1 x2)))
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(defun loop-tassoc (kwd alist)
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(and (symbolp kwd) (assoc kwd alist :test #'string=)))
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(defun loop-tmember (kwd list)
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(and (symbolp kwd) (member kwd list :test #'string=)))
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(defun loop-lookup-keyword (loop-token table)
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(and (symbolp loop-token)
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(values (gethash (symbol-name loop-token) table))))
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(defmacro loop-store-table-data (symbol table datum)
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`(setf (gethash (symbol-name ,symbol) ,table) ,datum))
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(defstruct (loop-universe
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(:print-function print-loop-universe)
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keywords ;hash table, value = (fn-name . extra-data).
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iteration-keywords ;hash table, value = (fn-name . extra-data).
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for-keywords ;hash table, value = (fn-name . extra-data).
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path-keywords ;hash table, value = (fn-name . extra-data).
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type-symbols ;hash table of type SYMBOLS, test EQ, value = CL type specifier.
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type-keywords ;hash table of type STRINGS, test EQUAL, value = CL type spec.
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ansi ;NIL, T, or :EXTENDED.
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implicit-for-required ;see loop-hack-iteration
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(defun print-loop-universe (u stream level)
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(declare (ignore level))
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(let ((str (case (loop-universe-ansi u)
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(:extended "Extended-ANSI")
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(t (loop-universe-ansi u)))))
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;;Cloe could be done with the above except for bootstrap lossage...
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(format stream "#<~S ~A ~X>" (type-of u) str (sys::address-of u))
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#+(or Genera cmu) ;@@@@ This is reallly the ANSI definition.
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(print-unreadable-object (u stream :type t :identity t)
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#-(or Genera CLOE cmu)
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(format stream "#<~S ~A>" (type-of u) str)
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;;;This is the "current" loop context in use when we are expanding a
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;;;loop. It gets bound on each invocation of LOOP.
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(defvar *loop-universe*)
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(defun make-standard-loop-universe (&key keywords for-keywords iteration-keywords path-keywords
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type-keywords type-symbols ansi)
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#-(and CLOE Source-Bootstrap) (check-type ansi (member nil t :extended))
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(flet ((maketable (entries)
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(let* ((size (length entries))
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(ht (make-hash-table :size (if (< size 10) 10 size) :test #'equal)))
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(dolist (x entries) (setf (gethash (symbol-name (car x)) ht) (cadr x)))
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:keywords (maketable keywords)
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:for-keywords (maketable for-keywords)
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:iteration-keywords (maketable iteration-keywords)
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:path-keywords (maketable path-keywords)
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:implicit-for-required (not (null ansi))
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:type-keywords (maketable type-keywords)
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:type-symbols (let* ((size (length type-symbols))
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(ht (make-hash-table :size (if (< size 10) 10 size) :test #'eq)))
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(dolist (x type-symbols)
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(if (atom x) (setf (gethash x ht) x) (setf (gethash (car x) ht) (cadr x))))
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(defvar *loop-destructuring-hooks*
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"If not NIL, this must be a list of two things:
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a LET-like macro, and a SETQ-like macro, which perform LOOP-style destructuring.")
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(defun loop-make-psetq (frobs)
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(if (null (cddr frobs)) (cadr frobs)
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`(prog1 ,(cadr frobs)
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,(loop-make-psetq (cddr frobs))))))))
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(defun loop-make-desetq (var-val-pairs)
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(if (null var-val-pairs)
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(cons (if *loop-destructuring-hooks*
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(cadr *loop-destructuring-hooks*)
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(defvar *loop-desetq-temporary*
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(make-symbol "LOOP-DESETQ-TEMP"))
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(defmacro loop-really-desetq (&environment env &rest var-val-pairs)
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(labels ((find-non-null (var)
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;; see if there's any non-null thing here
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;; recurse if the list element is itself a list
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(do ((tail var)) ((not (consp tail)) tail)
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(when (find-non-null (pop tail)) (return t))))
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(loop-desetq-internal (var val &optional temp)
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;; returns a list of actions to be performed
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;; don't lose possible side-effects
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(if (eq (car val) 'prog1)
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;; these can come from psetq or desetq below.
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;; throw away the value, keep the side-effects.
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;;Special case is for handling an expanded POP.
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(mapcan #'(lambda (x)
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(or (not (eq (car x) 'car))
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(not (symbolp (cadr x)))
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(not (symbolp (setq x (macroexpand x env)))))
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(let* ((car (car var))
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(car-non-null (find-non-null car))
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(cdr-non-null (find-non-null cdr)))
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(when (or car-non-null cdr-non-null)
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(temp (or temp *loop-desetq-temporary*))
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(body #+LOOP-Prefer-POP `(,@(loop-desetq-internal
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(setq ,temp (cdr ,temp))))
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,@(loop-desetq-internal cdr temp temp))
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#-LOOP-Prefer-POP `(,@(loop-desetq-internal car `(car ,temp))
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(setq ,temp (cdr ,temp))
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,@(loop-desetq-internal cdr temp temp))))
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`(,@(unless (eq temp val)
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`((setq ,temp ,val)))
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`((let ((,temp ,val))
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(loop-desetq-internal car `(car ,val) temp)))))
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`((setq ,var ,val)))))))
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((null var-val-pairs)
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(if (null (cdr actions)) (car actions) `(progn ,@(nreverse actions))))
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(setq actions (revappend
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(loop-desetq-internal (pop var-val-pairs) (pop var-val-pairs))
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;;;; LOOP-local variables
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;;;This is the "current" pointer into the LOOP source code.
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(defvar *loop-source-code*)
620
;;;This is the pointer to the original, for things like NAMED that
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;;;insist on being in a particular position
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(defvar *loop-original-source-code*)
625
;;;This is *loop-source-code* as of the "last" clause. It is used
626
;;;primarily for generating error messages (see loop-error, loop-warn).
627
(defvar *loop-source-context*)
630
;;;List of names for the LOOP, supplied by the NAMED clause.
631
(defvar *loop-names*)
633
;;;The macroexpansion environment given to the macro.
634
(defvar *loop-macro-environment*)
636
;;;This holds variable names specified with the USING clause.
637
;;; See LOOP-NAMED-VARIABLE.
638
(defvar *loop-named-variables*)
640
;;; LETlist-like list being accumulated for one group of parallel bindings.
641
(defvar *loop-variables*)
643
;;;List of declarations being accumulated in parallel with
645
(defvar *loop-declarations*)
647
;;;Used by LOOP for destructuring binding, if it is doing that itself.
648
;;; See loop-make-variable.
649
(defvar *loop-desetq-crocks*)
651
;;; List of wrapping forms, innermost first, which go immediately inside
652
;;; the current set of parallel bindings being accumulated in
653
;;; *loop-variables*. The wrappers are appended onto a body. E.g.,
654
;;; this list could conceivably has as its value ((with-open-file (g0001
655
;;; g0002 ...))), with g0002 being one of the bindings in
656
;;; *loop-variables* (this is why the wrappers go inside of the variable
658
(defvar *loop-wrappers*)
660
;;;This accumulates lists of previous values of *loop-variables* and the
661
;;;other lists above, for each new nesting of bindings. See
663
(defvar *loop-bind-stack*)
665
;;;This is a LOOP-global variable for the (obsolete) NODECLARE clause
666
;;;which inhibits LOOP from actually outputting a type declaration for
667
;;;an iteration (or any) variable.
668
(defvar *loop-nodeclare*)
670
;;;This is simply a list of LOOP iteration variables, used for checking
672
(defvar *loop-iteration-variables*)
675
;;;List of prologue forms of the loop, accumulated in reverse order.
676
(defvar *loop-prologue*)
678
(defvar *loop-before-loop*)
680
(defvar *loop-after-body*)
682
;;;This is T if we have emitted any body code, so that iteration driving
683
;;;clauses can be disallowed. This is not strictly the same as
684
;;;checking *loop-body*, because we permit some clauses such as RETURN
685
;;;to not be considered "real" body (so as to permit the user to "code"
686
;;;an abnormal return value "in loop").
687
(defvar *loop-emitted-body*)
690
;;;List of epilogue forms (supplied by FINALLY generally), accumulated
691
;;; in reverse order.
692
(defvar *loop-epilogue*)
694
;;;List of epilogue forms which are supplied after the above "user"
695
;;;epilogue. "normal" termination return values are provide by putting
696
;;;the return form in here. Normally this is done using
697
;;;loop-emit-final-value, q.v.
698
(defvar *loop-after-epilogue*)
700
;;;The "culprit" responsible for supplying a final value from the loop.
701
;;;This is so loop-emit-final-value can moan about multiple return
702
;;;values being supplied.
703
(defvar *loop-final-value-culprit*)
705
;;;If not NIL, we are in some branch of a conditional. Some clauses may
707
(defvar *loop-inside-conditional*)
709
;;;If not NIL, this is a temporary bound around the loop for holding the
710
;;;temporary value for "it" in things like "when (f) collect it". It
711
;;;may be used as a supertemporary by some other things.
712
(defvar *loop-when-it-variable*)
714
;;;Sometimes we decide we need to fold together parts of the loop, but
715
;;;some part of the generated iteration code is different for the first
716
;;;and remaining iterations. This variable will be the temporary which
717
;;;is the flag used in the loop to tell whether we are in the first or
718
;;;remaining iterations.
719
(defvar *loop-never-stepped-variable*)
721
;;;List of all the value-accumulation descriptor structures in the loop.
722
;;; See loop-get-collection-info.
723
(defvar *loop-collection-cruft*) ; for multiple COLLECTs (etc)
726
;;;; Code Analysis Stuff
729
(defun loop-constant-fold-if-possible (form &optional expected-type)
730
#+Genera (declare (values new-form constantp constant-value))
731
(let ((new-form form) (constantp nil) (constant-value nil))
732
#+Genera (setq new-form (compiler:optimize-form form *loop-macro-environment*
734
:do-macro-expansion t
735
:do-named-constants t
738
:do-constant-folding t
740
constantp (constantp new-form *loop-macro-environment*)
741
constant-value (and constantp (lt:evaluate-constant new-form *loop-macro-environment*)))
742
#-Genera (when (setq constantp (constantp new-form))
743
(setq constant-value (eval new-form)))
744
(when (and constantp expected-type)
745
(unless (typep constant-value expected-type)
746
(loop-warn "The form ~S evaluated to ~S, which was not of the anticipated type ~S."
747
form constant-value expected-type)
748
(setq constantp nil constant-value nil)))
749
(values new-form constantp constant-value)))
752
(defun loop-constantp (form)
753
#+Genera (constantp form *loop-macro-environment*)
754
#-Genera (constantp form))
757
;;;; LOOP Iteration Optimization
759
(defvar *loop-duplicate-code*
763
(defvar *loop-iteration-flag-variable*
764
(make-symbol "LOOP-NOT-FIRST-TIME"))
767
(defun loop-code-duplication-threshold (env)
768
(multiple-value-bind (speed space) (loop-optimization-quantities env)
769
(+ 40 (* (- speed space) 10))))
772
(defmacro loop-body (&environment env
778
&aux rbefore rafter flagvar)
779
(unless (= (length before-loop) (length after-loop))
780
(error "LOOP-BODY called with non-synched before- and after-loop lists."))
781
;;All our work is done from these copies, working backwards from the end:
782
(setq rbefore (reverse before-loop) rafter (reverse after-loop))
788
(when (and (consp x) (member (car x) '(go return return-from)))
791
(pify (l) (if (null (cdr l)) (car l) `(progn ,@l)))
793
(let ((form `(tagbody
794
,@(psimp (append prologue (nreverse rbefore)))
796
,@(psimp (append main-body (nreconc rafter `((go next-loop)))))
798
,@(psimp epilogue))))
799
(if flagvar `(let ((,flagvar nil)) ,form) form))))
800
(when (or *loop-duplicate-code* (not rbefore))
801
(return-from loop-body (makebody)))
802
;; This outer loop iterates once for each not-first-time flag test generated
803
;; plus once more for the forms that don't need a flag test
804
(do ((threshold (loop-code-duplication-threshold env))) (nil)
805
(declare (fixnum threshold))
806
;; Go backwards from the ends of before-loop and after-loop merging all the equivalent
807
;; forms into the body.
808
(do () ((or (null rbefore) (not (equal (car rbefore) (car rafter)))))
809
(push (pop rbefore) main-body)
811
(unless rbefore (return (makebody)))
812
;; The first forms in rbefore & rafter (which are the chronologically
813
;; last forms in the list) differ, therefore they cannot be moved
814
;; into the main body. If everything that chronologically precedes
815
;; them either differs or is equal but is okay to duplicate, we can
816
;; just put all of rbefore in the prologue and all of rafter after
817
;; the body. Otherwise, there is something that is not okay to
818
;; duplicate, so it and everything chronologically after it in
819
;; rbefore and rafter must go into the body, with a flag test to
820
;; distinguish the first time around the loop from later times.
821
;; What chronologically precedes the non-duplicatable form will
822
;; be handled the next time around the outer loop.
823
(do ((bb rbefore (cdr bb)) (aa rafter (cdr aa)) (lastdiff nil) (count 0) (inc nil))
824
((null bb) (return-from loop-body (makebody))) ;Did it.
825
(cond ((not (equal (car bb) (car aa))) (setq lastdiff bb count 0))
826
((or (not (setq inc (estimate-code-size (car bb) env)))
827
(> (incf count inc) threshold))
828
;; Ok, we have found a non-duplicatable piece of code. Everything
829
;; chronologically after it must be in the central body.
830
;; Everything chronologically at and after lastdiff goes into the
831
;; central body under a flag test.
832
(let ((then nil) (else nil))
834
(push (pop rbefore) else)
835
(push (pop rafter) then)
836
(when (eq rbefore (cdr lastdiff)) (return)))
838
(push `(setq ,(setq flagvar *loop-iteration-flag-variable*) t) else))
839
(push `(if ,flagvar ,(pify (psimp then)) ,(pify (psimp else)))
841
;; Everything chronologically before lastdiff until the non-duplicatable form (car bb)
842
;; is the same in rbefore and rafter so just copy it into the body
845
(push (pop rbefore) main-body)
846
(when (eq rbefore (cdr bb)) (return)))
851
(defun duplicatable-code-p (expr env)
853
(let ((ans (estimate-code-size expr env)))
854
(declare (fixnum ans))
855
;;@@@@ Use (DECLARATION-INFORMATION 'OPTIMIZE ENV) here to get an alist of
856
;; optimize quantities back to help quantify how much code we are willing to
861
(defvar *special-code-sizes*
862
'((return 0) (progn 0)
863
(null 1) (not 1) (eq 1) (car 1) (cdr 1)
864
(when 1) (unless 1) (if 1)
865
(caar 2) (cadr 2) (cdar 2) (cddr 2)
866
(caaar 3) (caadr 3) (cadar 3) (caddr 3) (cdaar 3) (cdadr 3) (cddar 3) (cdddr 3)
867
(caaaar 4) (caaadr 4) (caadar 4) (caaddr 4)
868
(cadaar 4) (cadadr 4) (caddar 4) (cadddr 4)
869
(cdaaar 4) (cdaadr 4) (cdadar 4) (cdaddr 4)
870
(cddaar 4) (cddadr 4) (cdddar 4) (cddddr 4)))
873
(defvar *estimate-code-size-punt*
877
labels lambda let let* locally
878
macrolet multiple-value-bind
886
(defun destructuring-size (x)
887
(do ((x x (cdr x)) (n 0 (+ (destructuring-size (car x)) n)))
888
((atom x) (+ n (if (null x) 0 1)))))
891
(defun estimate-code-size (x env)
892
(catch 'estimate-code-size
893
(estimate-code-size-1 x env)))
896
(defun estimate-code-size-1 (x env)
897
(flet ((list-size (l)
900
(dolist (x l n) (incf n (estimate-code-size-1 x env))))))
901
;;@@@@ ???? (declare (function list-size (list) fixnum))
902
(cond ((constantp x #+Genera env) 1)
903
((symbolp x) (multiple-value-bind (new-form expanded-p) (macroexpand-1 x env)
904
(if expanded-p (estimate-code-size-1 new-form env) 1)))
905
((atom x) 1) ;??? self-evaluating???
907
(let ((fn (car x)) (tem nil) (n 0))
908
(declare (symbol fn) (fixnum n))
909
(macrolet ((f (overhead &optional (args nil args-p))
910
`(the fixnum (+ (the fixnum ,overhead)
911
(the fixnum (list-size ,(if args-p args '(cdr x))))))))
912
(cond ((setq tem (get fn 'estimate-code-size))
915
(t (funcall tem x env))))
916
((setq tem (assoc fn *special-code-sizes*)) (f (second tem)))
918
((eq fn 'compiler:invisible-references) (list-size (cddr x)))
920
(dolist (clause (cdr x) n) (incf n (list-size clause)) (incf n)))
922
(do ((l (cdr x) (cdr l))) ((null l) n)
923
(setq n (+ n (destructuring-size (car l)) (estimate-code-size-1 (cadr l) env)))))
924
((member fn '(setq psetq))
925
(do ((l (cdr x) (cdr l))) ((null l) n)
926
(setq n (+ n (estimate-code-size-1 (cadr l) env) 1))))
929
;;This skirts the issue of implementationally-defined lambda macros
930
;; by recognizing CL function names and nothing else.
931
(if t;(ext:valid-function-name-p (cadr x))
933
(throw 'duplicatable-code-p nil)))
934
((eq fn 'multiple-value-setq) (f (length (second x)) (cddr x)))
935
((eq fn 'return-from) (1+ (estimate-code-size-1 (third x) env)))
936
((or (special-operator-p fn) (member fn *estimate-code-size-punt*))
937
(throw 'estimate-code-size nil))
938
(t (multiple-value-bind (new-form expanded-p) (macroexpand-1 x env)
940
(estimate-code-size-1 new-form env)
942
(t (throw 'estimate-code-size nil)))))
948
(defun loop-context ()
949
(do ((l *loop-source-context* (cdr l)) (new nil (cons (car l) new)))
950
((eq l (cdr *loop-source-code*)) (nreverse new))))
953
(defun loop-error (format-string &rest format-args)
954
#+(or Genera CLOE) (declare (dbg:error-reporter))
955
#+Genera (setq format-args (copy-list format-args)) ;Don't ask.
956
(specific-error :invalid-form "~?~%Current LOOP context:~{ ~S~}."
957
format-string format-args (loop-context)))
960
(defun loop-warn (format-string &rest format-args)
961
(warn "~?~%Current LOOP context:~{ ~S~}." format-string format-args (loop-context)))
964
(defun loop-check-data-type (specified-type required-type
965
&optional (default-type required-type))
966
(if (null specified-type)
968
(multiple-value-bind (a b) (subtypep specified-type required-type)
970
(loop-warn "LOOP couldn't verify that ~S is a subtype of the required type ~S."
971
specified-type required-type))
973
(loop-error "Specified data type ~S is not a subtype of ~S."
974
specified-type required-type)))
978
;;;INTERFACE: Traditional, ANSI, Lucid.
979
(defmacro loop-finish ()
980
"Causes the iteration to terminate \"normally\", the same as implicit
981
termination by an iteration driving clause, or by use of WHILE or
982
UNTIL -- the epilogue code (if any) will be run, and any implicitly
983
collected result will be returned as the value of the LOOP."
988
(defun subst-gensyms-for-nil (tree)
989
(declare (special *ignores*))
991
((null tree) (car (push (loop-gentemp) *ignores*)))
993
(t (cons (subst-gensyms-for-nil (car tree))
994
(subst-gensyms-for-nil (cdr tree))))))
996
(defun loop-build-destructuring-bindings (crocks forms)
998
(let ((*ignores* ()))
999
(declare (special *ignores*))
1000
`((destructuring-bind ,(subst-gensyms-for-nil (car crocks))
1002
(declare (ignore ,@*ignores*))
1003
,@(loop-build-destructuring-bindings (cddr crocks) forms))))
1006
(defun loop-translate (*loop-source-code* *loop-macro-environment* *loop-universe*)
1007
(let ((*loop-original-source-code* *loop-source-code*)
1008
(*loop-source-context* nil)
1009
(*loop-iteration-variables* nil)
1010
(*loop-variables* nil)
1011
(*loop-nodeclare* nil)
1012
(*loop-named-variables* nil)
1013
(*loop-declarations* nil)
1014
(*loop-desetq-crocks* nil)
1015
(*loop-bind-stack* nil)
1016
(*loop-prologue* nil)
1017
(*loop-wrappers* nil)
1018
(*loop-before-loop* nil)
1020
(*loop-emitted-body* nil)
1021
(*loop-after-body* nil)
1022
(*loop-epilogue* nil)
1023
(*loop-after-epilogue* nil)
1024
(*loop-final-value-culprit* nil)
1025
(*loop-inside-conditional* nil)
1026
(*loop-when-it-variable* nil)
1027
(*loop-never-stepped-variable* nil)
1029
(*loop-collection-cruft* nil))
1030
(loop-iteration-driver)
1032
(let ((answer `(loop-body
1033
,(nreverse *loop-prologue*)
1034
,(nreverse *loop-before-loop*)
1035
,(nreverse *loop-body*)
1036
,(nreverse *loop-after-body*)
1037
,(nreconc *loop-epilogue* (nreverse *loop-after-epilogue*)))))
1038
(dolist (entry *loop-bind-stack*)
1039
(let ((vars (first entry))
1040
(dcls (second entry))
1041
(crocks (third entry))
1042
(wrappers (fourth entry)))
1043
(dolist (w wrappers)
1044
(setq answer (append w (list answer))))
1045
(when (or vars dcls crocks)
1046
(let ((forms (list answer)))
1047
;;(when crocks (push crocks forms))
1048
(when dcls (push `(declare ,@dcls) forms))
1049
(setq answer `(,(cond ((not vars) 'locally)
1050
(*loop-destructuring-hooks* (first *loop-destructuring-hooks*))
1053
,@(loop-build-destructuring-bindings crocks forms)))))))
1055
(do () ((null (car *loop-names*)) answer)
1056
(setq answer `(block ,(pop *loop-names*) ,answer)))
1057
`(block nil ,answer)))))
1060
(defun loop-iteration-driver ()
1061
(do () ((null *loop-source-code*))
1062
(let ((keyword (car *loop-source-code*)) (tem nil))
1063
(cond ((not (symbolp keyword))
1064
(loop-error "~S found where LOOP keyword expected." keyword))
1065
(t (setq *loop-source-context* *loop-source-code*)
1067
(cond ((setq tem (loop-lookup-keyword keyword (loop-universe-keywords *loop-universe*)))
1068
;;It's a "miscellaneous" toplevel LOOP keyword (do, collect, named, etc.)
1069
(apply (symbol-function (first tem)) (rest tem)))
1070
((setq tem (loop-lookup-keyword keyword (loop-universe-iteration-keywords *loop-universe*)))
1071
(loop-hack-iteration tem))
1072
((loop-tmember keyword '(and else))
1073
;; Alternative is to ignore it, ie let it go around to the next keyword...
1074
(loop-error "Secondary clause misplaced at top level in LOOP macro: ~S ~S ~S ..."
1075
keyword (car *loop-source-code*) (cadr *loop-source-code*)))
1076
(t (loop-error "~S is an unknown keyword in LOOP macro." keyword))))))))
1080
(defun loop-pop-source ()
1081
(if *loop-source-code*
1082
(pop *loop-source-code*)
1083
(loop-error "LOOP source code ran out when another token was expected.")))
1086
(defun loop-get-compound-form ()
1087
(let ((form (loop-get-form)))
1088
(unless (consp form)
1089
(loop-error "Compound form expected, but found ~A." form))
1092
(defun loop-get-progn ()
1093
(do ((forms (list (loop-get-compound-form))
1094
(cons (loop-get-compound-form) forms))
1095
(nextform (car *loop-source-code*)
1096
(car *loop-source-code*)))
1098
(if (null (cdr forms)) (car forms) (cons 'progn (nreverse forms))))))
1101
(defun loop-get-form ()
1102
(if *loop-source-code*
1104
(loop-error "LOOP code ran out where a form was expected.")))
1107
(defun loop-construct-return (form)
1108
`(return-from ,(car *loop-names*) ,form))
1111
(defun loop-pseudo-body (form)
1112
(cond ((or *loop-emitted-body* *loop-inside-conditional*) (push form *loop-body*))
1113
(t (push form *loop-before-loop*) (push form *loop-after-body*))))
1115
(defun loop-emit-body (form)
1116
(setq *loop-emitted-body* t)
1117
(loop-pseudo-body form))
1119
(defun loop-emit-final-value (&optional (form nil form-supplied-p))
1120
(when form-supplied-p
1121
(push (loop-construct-return form) *loop-after-epilogue*))
1122
(when *loop-final-value-culprit*
1123
(loop-warn "LOOP clause is providing a value for the iteration,~@
1124
however one was already established by a ~S clause."
1125
*loop-final-value-culprit*))
1126
(setq *loop-final-value-culprit* (car *loop-source-context*)))
1129
(defun loop-disallow-conditional (&optional kwd)
1130
#+(or Genera CLOE) (declare (dbg:error-reporter))
1131
(when *loop-inside-conditional*
1132
(loop-error "~:[This LOOP~;The LOOP ~:*~S~] clause is not permitted inside a conditional." kwd)))
1134
(defun loop-disallow-anonymous-collectors ()
1135
(when (find-if-not 'loop-collector-name *loop-collection-cruft*)
1136
(loop-error "This LOOP clause is not permitted with anonymous collectors.")))
1138
(defun loop-disallow-aggregate-booleans ()
1139
(when (loop-tmember *loop-final-value-culprit* '(always never thereis))
1140
(loop-error "This anonymous collection LOOP clause is not permitted with aggregate booleans.")))
1147
(defun loop-typed-init (data-type)
1148
(when (and data-type (subtypep data-type 'number))
1149
(if (or (subtypep data-type 'float) (subtypep data-type '(complex float)))
1150
(coerce 0 data-type)
1154
(defun loop-optional-type (&optional variable)
1155
;;No variable specified implies that no destructuring is permissible.
1156
(and *loop-source-code* ;Don't get confused by NILs...
1157
(let ((z (car *loop-source-code*)))
1158
(cond ((loop-tequal z 'of-type)
1159
;;This is the syntactically unambigous form in that the form of the
1160
;; type specifier does not matter. Also, it is assumed that the
1161
;; type specifier is unambiguously, and without need of translation,
1162
;; a common lisp type specifier or pattern (matching the variable) thereof.
1167
;;This is the (sort of) "old" syntax, even though we didn't used to support all of
1168
;; these type symbols.
1169
(let ((type-spec (or (gethash z (loop-universe-type-symbols *loop-universe*))
1170
(gethash (symbol-name z) (loop-universe-type-keywords *loop-universe*)))))
1175
;;This is our sort-of old syntax. But this is only valid for when we are destructuring,
1176
;; so we will be compulsive (should we really be?) and require that we in fact be
1177
;; doing variable destructuring here. We must translate the old keyword pattern typespec
1178
;; into a fully-specified pattern of real type specifiers here.
1179
(if (consp variable)
1182
"~S found where a LOOP keyword, LOOP type keyword, or LOOP type pattern expected."
1184
(loop-error "~S found where a LOOP keyword or LOOP type keyword expected." z))
1186
(labels ((translate (k v)
1187
(cond ((null k) nil)
1190
(or (gethash k (loop-universe-type-symbols *loop-universe*))
1191
(gethash (symbol-name k) (loop-universe-type-keywords *loop-universe*))
1193
"Destructuring type pattern ~S contains unrecognized type keyword ~S."
1198
"Destructuring type pattern ~S doesn't match variable pattern ~S."
1200
(t (cons (translate (car k) (car v)) (translate (cdr k) (cdr v))))))
1202
(if (atom v) typ (cons (replicate typ (car v)) (replicate typ (cdr v))))))
1203
(translate z variable)))))))
1210
(defun loop-bind-block ()
1211
(when (or *loop-variables* *loop-declarations* *loop-wrappers*)
1212
(push (list (nreverse *loop-variables*) *loop-declarations* *loop-desetq-crocks* *loop-wrappers*)
1214
(setq *loop-variables* nil
1215
*loop-declarations* nil
1216
*loop-desetq-crocks* nil
1217
*loop-wrappers* nil)))
1219
(defun loop-variable-p (name)
1220
(do ((entry *loop-bind-stack* (cdr entry))) (nil)
1223
((assoc name (caar entry) :test #'eq)
1226
(defun loop-make-variable (name initialization dtype &optional iteration-variable-p)
1228
(cond ((not (null initialization))
1229
(push (list (setq name (loop-gentemp 'loop-ignore-))
1232
(push `(ignore ,name) *loop-declarations*))))
1234
(cond (iteration-variable-p
1235
(if (member name *loop-iteration-variables*)
1236
(loop-error "Duplicated LOOP iteration variable ~S." name)
1237
(push name *loop-iteration-variables*)))
1238
((assoc name *loop-variables*)
1239
(loop-error "Duplicated variable ~S in LOOP parallel binding." name)))
1240
(unless (symbolp name)
1241
(loop-error "Bad variable ~S somewhere in LOOP." name))
1242
(loop-declare-variable name dtype)
1243
;; We use ASSOC on this list to check for duplications (above),
1244
;; so don't optimize out this list:
1245
(push (list name (or initialization (loop-typed-init dtype)))
1248
(cond (*loop-destructuring-hooks*
1249
(loop-declare-variable name dtype)
1250
(push (list name initialization) *loop-variables*))
1251
(t (let ((newvar (loop-gentemp 'loop-destructure-)))
1252
(loop-declare-variable name dtype)
1253
(push (list newvar initialization) *loop-variables*)
1254
;; *LOOP-DESETQ-CROCKS* gathered in reverse order.
1255
(setq *loop-desetq-crocks*
1256
(list* name newvar *loop-desetq-crocks*))
1258
(loop-make-variable name nil dtype iteration-variable-p)))))
1259
(t (let ((tcar nil) (tcdr nil))
1260
(if (atom dtype) (setq tcar (setq tcdr dtype))
1261
(setq tcar (car dtype) tcdr (cdr dtype)))
1262
(loop-make-variable (car name) nil tcar iteration-variable-p)
1263
(loop-make-variable (cdr name) nil tcdr iteration-variable-p))))
1267
(defun loop-make-iteration-variable (name initialization dtype)
1268
(loop-make-variable name initialization dtype t))
1271
(defun loop-declare-variable (name dtype)
1272
(cond ((or (null name) (null dtype) (eq dtype t)) nil)
1274
(unless (or (eq dtype t) (member (the symbol name) *loop-nodeclare*))
1275
(let ((dtype #-cmu dtype
1277
(let ((init (loop-typed-init dtype)))
1278
(if (typep init dtype)
1280
`(or (member ,init) ,dtype)))))
1281
(push `(type ,dtype ,name) *loop-declarations*))))
1283
(cond ((consp dtype)
1284
(loop-declare-variable (car name) (car dtype))
1285
(loop-declare-variable (cdr name) (cdr dtype)))
1286
(t (loop-declare-variable (car name) dtype)
1287
(loop-declare-variable (cdr name) dtype))))
1288
(t (error "Invalid LOOP variable passed in: ~S." name))))
1291
(defun loop-maybe-bind-form (form data-type)
1292
(if (loop-constantp form)
1294
(loop-make-variable (loop-gentemp 'loop-bind-) form data-type)))
1298
(defun loop-do-if (for negatep)
1299
(let ((form (loop-get-form))
1300
(*loop-inside-conditional* t)
1303
(flet ((get-clause (for)
1304
(do ((body nil)) (nil)
1305
(let ((key (car *loop-source-code*)) (*loop-body* nil) data)
1306
(cond ((not (symbolp key))
1308
"~S found where keyword expected getting LOOP clause after ~S."
1310
(t (setq *loop-source-context* *loop-source-code*)
1312
(when (and (loop-tequal (car *loop-source-code*) 'it)
1314
(setq *loop-source-code*
1315
(cons (or it-p (setq it-p (loop-when-it-variable)))
1316
(cdr *loop-source-code*))))
1317
(cond ((or (not (setq data (loop-lookup-keyword
1318
key (loop-universe-keywords *loop-universe*))))
1319
(progn (apply (symbol-function (car data)) (cdr data))
1320
(null *loop-body*)))
1322
"~S does not introduce a LOOP clause that can follow ~S."
1324
(t (setq body (nreconc *loop-body* body)))))))
1325
(setq first-clause-p nil)
1326
(if (loop-tequal (car *loop-source-code*) :and)
1328
(return (if (cdr body) `(progn ,@(nreverse body)) (car body)))))))
1329
(let ((then (get-clause for))
1330
(else (when (loop-tequal (car *loop-source-code*) :else)
1332
(list (get-clause :else)))))
1333
(when (loop-tequal (car *loop-source-code*) :end)
1335
(when it-p (setq form `(setq ,it-p ,form)))
1337
`(if ,(if negatep `(not ,form) form)
1342
(defun loop-do-initially ()
1343
(loop-disallow-conditional :initially)
1344
(push (loop-get-progn) *loop-prologue*))
1346
(defun loop-do-finally ()
1347
(loop-disallow-conditional :finally)
1348
(push (loop-get-progn) *loop-epilogue*))
1350
(defun loop-do-do ()
1351
(loop-emit-body (loop-get-progn)))
1353
(defun loop-do-named ()
1354
(let ((name (loop-pop-source)))
1355
(unless (symbolp name)
1356
(loop-error "~S is an invalid name for your LOOP." name))
1357
(when (or *loop-before-loop* *loop-body* *loop-after-epilogue* *loop-inside-conditional*)
1358
(loop-error "The NAMED ~S clause occurs too late." name))
1360
(loop-error "You may only use one NAMED clause in your loop: NAMED ~S ... NAMED ~S."
1361
(car *loop-names*) name))
1362
(setq *loop-names* (list name nil))))
1364
(defun loop-do-return ()
1365
(loop-pseudo-body (loop-construct-return (loop-get-form))))
1368
;;;; Value Accumulation: List
1371
(defstruct (loop-collector
1379
(data nil)) ;collector-specific data
1382
(defun loop-get-collection-info (collector class default-type)
1383
(let ((form (loop-get-form))
1384
(dtype (and (not (loop-universe-ansi *loop-universe*)) (loop-optional-type)))
1385
(name (when (loop-tequal (car *loop-source-code*) 'into)
1387
(loop-pop-source))))
1388
(when (not (symbolp name))
1389
(loop-error "Value accumulation recipient name, ~S, is not a symbol." name))
1391
(loop-disallow-aggregate-booleans))
1393
(setq dtype (or (loop-optional-type) default-type)))
1394
(let ((cruft (find (the symbol name) *loop-collection-cruft*
1395
:key #'loop-collector-name)))
1397
(when (and name (loop-variable-p name))
1398
(loop-error "Variable ~S cannot be used in INTO clause" name))
1399
(push (setq cruft (make-loop-collector
1400
:name name :class class
1401
:history (list collector) :dtype dtype))
1402
*loop-collection-cruft*))
1403
(t (unless (eq (loop-collector-class cruft) class)
1405
"Incompatible kinds of LOOP value accumulation specified for collecting~@
1406
~:[as the value of the LOOP~;~:*INTO ~S~]: ~S and ~S."
1407
name (car (loop-collector-history cruft)) collector))
1408
(unless (equal dtype (loop-collector-dtype cruft))
1410
"Unequal datatypes specified in different LOOP value accumulations~@
1411
into ~S: ~S and ~S."
1412
name dtype (loop-collector-dtype cruft))
1413
(when (eq (loop-collector-dtype cruft) t)
1414
(setf (loop-collector-dtype cruft) dtype)))
1415
(push collector (loop-collector-history cruft))))
1416
(values cruft form))))
1419
(defun loop-list-collection (specifically) ;NCONC, LIST, or APPEND
1420
(multiple-value-bind (lc form) (loop-get-collection-info specifically 'list 'list)
1421
(let ((tempvars (loop-collector-tempvars lc)))
1423
(setf (loop-collector-tempvars lc)
1424
(setq tempvars (list* (loop-gentemp 'loop-list-head-)
1425
(loop-gentemp 'loop-list-tail-)
1426
(and (loop-collector-name lc)
1427
(list (loop-collector-name lc))))))
1428
(push `(with-loop-list-collection-head ,tempvars) *loop-wrappers*)
1429
(unless (loop-collector-name lc)
1430
(loop-emit-final-value `(loop-collect-answer ,(car tempvars) ,@(cddr tempvars)))))
1432
(list (setq form `(list ,form)))
1434
(append (unless (and (consp form) (eq (car form) 'list))
1435
(setq form `(loop-copylist* ,form)))))
1436
(loop-emit-body `(loop-collect-rplacd ,tempvars ,form)))))
1439
;;;; Value Accumulation: max, min, sum, count.
1443
(defun loop-sum-collection (specifically required-type default-type) ;SUM, COUNT
1444
(multiple-value-bind (lc form)
1445
(loop-get-collection-info specifically 'sum default-type)
1446
(loop-check-data-type (loop-collector-dtype lc) required-type)
1447
(let ((tempvars (loop-collector-tempvars lc)))
1449
(setf (loop-collector-tempvars lc)
1450
(setq tempvars (list (loop-make-variable
1451
(or (loop-collector-name lc)
1452
(loop-gentemp 'loop-sum-))
1453
nil (loop-collector-dtype lc)))))
1454
(unless (loop-collector-name lc)
1455
(loop-emit-final-value (car (loop-collector-tempvars lc)))))
1457
(if (eq specifically 'count)
1459
(setq ,(car tempvars)
1460
,(hide-variable-reference t (car tempvars) `(1+ ,(car tempvars)))))
1461
`(setq ,(car tempvars)
1462
(+ ,(hide-variable-reference t (car tempvars) (car tempvars))
1467
(defun loop-maxmin-collection (specifically)
1468
(multiple-value-bind (lc form)
1469
(loop-get-collection-info specifically 'maxmin *loop-real-data-type*)
1470
(loop-check-data-type (loop-collector-dtype lc) *loop-real-data-type*)
1471
(let ((data (loop-collector-data lc)))
1473
(setf (loop-collector-data lc)
1474
(setq data (make-loop-minimax
1475
(or (loop-collector-name lc) (loop-gentemp 'loop-maxmin-))
1476
(loop-collector-dtype lc))))
1477
(unless (loop-collector-name lc)
1478
(loop-emit-final-value (loop-minimax-answer-variable data))))
1479
(loop-note-minimax-operation specifically data)
1480
(push `(with-minimax-value ,data) *loop-wrappers*)
1481
(loop-emit-body `(loop-accumulate-minimax-value ,data ,specifically ,form))
1485
;;;; Value Accumulation: Aggregate Booleans
1487
;;;ALWAYS and NEVER.
1488
;;; Under ANSI these are not permitted to appear under conditionalization.
1489
(defun loop-do-always (restrictive negate)
1490
(let ((form (loop-get-form)))
1491
(when restrictive (loop-disallow-conditional))
1492
(loop-disallow-anonymous-collectors)
1493
(loop-emit-body `(,(if negate 'when 'unless) ,form
1494
,(loop-construct-return nil)))
1495
(loop-emit-final-value t)))
1500
;;; Under ANSI this is not permitted to appear under conditionalization.
1501
(defun loop-do-thereis (restrictive)
1502
(when restrictive (loop-disallow-conditional))
1503
(loop-disallow-anonymous-collectors)
1504
(loop-emit-final-value)
1505
(loop-emit-body `(when (setq ,(loop-when-it-variable) ,(loop-get-form))
1506
,(loop-construct-return *loop-when-it-variable*))))
1509
(defun loop-do-while (negate kwd &aux (form (loop-get-form)))
1510
(loop-disallow-conditional kwd)
1511
(loop-pseudo-body `(,(if negate 'when 'unless) ,form (go end-loop))))
1514
(defun loop-do-with ()
1515
(loop-disallow-conditional :with)
1516
(do ((var) (val) (dtype)) (nil)
1517
(setq var (loop-pop-source)
1518
dtype (loop-optional-type var)
1519
val (cond ((loop-tequal (car *loop-source-code*) :=)
1523
(when (and var (loop-variable-p var))
1524
(loop-error "Variable ~S has already been used" var))
1525
(loop-make-variable var val dtype)
1526
(if (loop-tequal (car *loop-source-code*) :and)
1528
(return (loop-bind-block)))))
1531
;;;; The iteration driver
1533
(defun loop-hack-iteration (entry)
1534
(flet ((make-endtest (list-of-forms)
1535
(cond ((null list-of-forms) nil)
1536
((member t list-of-forms) '(go end-loop))
1537
(t `(when ,(if (null (cdr (setq list-of-forms (nreverse list-of-forms))))
1539
(cons 'or list-of-forms))
1541
(do ((pre-step-tests nil)
1543
(post-step-tests nil)
1545
(pre-loop-pre-step-tests nil)
1546
(pre-loop-steps nil)
1547
(pre-loop-post-step-tests nil)
1548
(pre-loop-pseudo-steps nil)
1551
;; Note we collect endtests in reverse order, but steps in correct
1552
;; order. MAKE-ENDTEST does the nreverse for us.
1553
(setq tem (setq data (apply (symbol-function (first entry)) (rest entry))))
1554
(and (car tem) (push (car tem) pre-step-tests))
1555
(setq steps (nconc steps (loop-copylist* (car (setq tem (cdr tem))))))
1556
(and (car (setq tem (cdr tem))) (push (car tem) post-step-tests))
1557
(setq pseudo-steps (nconc pseudo-steps (loop-copylist* (car (setq tem (cdr tem))))))
1558
(setq tem (cdr tem))
1559
(when *loop-emitted-body*
1560
(loop-error "Iteration in LOOP follows body code."))
1561
(unless tem (setq tem data))
1562
(when (car tem) (push (car tem) pre-loop-pre-step-tests))
1563
(setq pre-loop-steps (nconc pre-loop-steps (loop-copylist* (car (setq tem (cdr tem))))))
1564
(when (car (setq tem (cdr tem))) (push (car tem) pre-loop-post-step-tests))
1565
(setq pre-loop-pseudo-steps (nconc pre-loop-pseudo-steps (loop-copylist* (cadr tem))))
1566
(unless (loop-tequal (car *loop-source-code*) :and)
1567
(setq *loop-before-loop* (list* (loop-make-desetq pre-loop-pseudo-steps)
1568
(make-endtest pre-loop-post-step-tests)
1569
(loop-make-psetq pre-loop-steps)
1570
(make-endtest pre-loop-pre-step-tests)
1572
*loop-after-body* (list* (loop-make-desetq pseudo-steps)
1573
(make-endtest post-step-tests)
1574
(loop-make-psetq steps)
1575
(make-endtest pre-step-tests)
1579
(loop-pop-source) ; flush the "AND"
1580
(when (and (not (loop-universe-implicit-for-required *loop-universe*))
1581
(setq tem (loop-lookup-keyword
1582
(car *loop-source-code*)
1583
(loop-universe-iteration-keywords *loop-universe*))))
1584
;;Latest ANSI clarification is that the FOR/AS after the AND must NOT be supplied.
1586
(setq entry tem)))))
1589
;;;; Main Iteration Drivers
1592
;FOR variable keyword ..args..
1593
(defun loop-do-for ()
1594
(let* ((var (loop-pop-source))
1595
(data-type (loop-optional-type var))
1596
(keyword (loop-pop-source))
1599
(setq first-arg (loop-get-form))
1600
(unless (and (symbolp keyword)
1601
(setq tem (loop-lookup-keyword
1603
(loop-universe-for-keywords *loop-universe*))))
1604
(loop-error "~S is an unknown keyword in FOR or AS clause in LOOP." keyword))
1605
(apply (car tem) var first-arg data-type (cdr tem))))
1607
(defun loop-do-repeat ()
1608
(loop-disallow-conditional :repeat)
1609
(let ((form (loop-get-form))
1611
(let ((var (loop-make-variable (loop-gentemp) form type)))
1612
(push `(when (minusp (decf ,var)) (go end-loop)) *loop-before-loop*)
1613
(push `(when (minusp (decf ,var)) (go end-loop)) *loop-after-body*)
1614
;; FIXME: What should
1615
;; (loop count t into a
1618
;; finally (return (list a b)))
1619
;; return: (3 3) or (4 3)? PUSHes above are for the former
1620
;; variant, L-P-B below for the latter.
1621
#+nil (loop-pseudo-body `(when (minusp (decf ,var)) (go end-loop))))))
1623
(defun loop-when-it-variable ()
1624
(or *loop-when-it-variable*
1625
(setq *loop-when-it-variable*
1626
(loop-make-variable (loop-gentemp 'loop-it-) nil nil))))
1629
;;;; Various FOR/AS Subdispatches
1632
;;;ANSI "FOR x = y [THEN z]" is sort of like the old Genera one when the THEN
1633
;;; is omitted (other than being more stringent in its placement), and like
1634
;;; the old "FOR x FIRST y THEN z" when the THEN is present. I.e., the first
1635
;;; initialization occurs in the loop body (first-step), not in the variable binding
1637
(defun loop-ansi-for-equals (var val data-type)
1638
(loop-make-iteration-variable var nil data-type)
1639
(cond ((loop-tequal (car *loop-source-code*) :then)
1640
;;Then we are the same as "FOR x FIRST y THEN z".
1642
`(() (,var ,(loop-get-form)) () ()
1643
() (,var ,val) () ()))
1644
(t ;;We are the same as "FOR x = y".
1645
`(() (,var ,val) () ()))))
1648
(defun loop-for-across (var val data-type)
1649
(loop-make-iteration-variable var nil data-type)
1650
(let ((vector-var (loop-gentemp 'loop-across-vector-))
1651
(index-var (loop-gentemp 'loop-across-index-)))
1652
(multiple-value-bind (vector-form constantp vector-value)
1653
(loop-constant-fold-if-possible val 'vector)
1655
vector-var vector-form
1656
(if (and (consp vector-form) (eq (car vector-form) 'the))
1659
#+Genera (push `(system:array-register ,vector-var) *loop-declarations*)
1660
(loop-make-variable index-var 0 'fixnum)
1662
(length-form (cond ((not constantp)
1663
(let ((v (loop-gentemp 'loop-across-limit-)))
1664
(push `(setq ,v (length ,vector-var)) *loop-prologue*)
1665
(loop-make-variable v 0 'fixnum)))
1666
(t (setq length (length vector-value)))))
1667
(first-test `(>= ,index-var ,length-form))
1668
(other-test first-test)
1669
(step `(,var (aref ,vector-var ,index-var)))
1670
(pstep `(,index-var (1+ ,index-var))))
1671
(declare (fixnum length))
1673
(setq first-test (= length 0))
1675
(setq other-test t)))
1676
`(,other-test ,step () ,pstep
1677
,@(and (not (eq first-test other-test)) `(,first-test ,step () ,pstep)))))))
1684
(defun loop-list-step (listvar)
1685
;;We are not equipped to analyze whether 'FOO is the same as #'FOO here in any
1686
;; sensible fashion, so let's give an obnoxious warning whenever 'FOO is used
1687
;; as the stepping function.
1688
;;While a Discerning Compiler may deal intelligently with (funcall 'foo ...), not
1689
;; recognizing FOO may defeat some LOOP optimizations.
1690
(let ((stepper (cond ((loop-tequal (car *loop-source-code*) :by)
1693
(t '(function cdr)))))
1694
(cond ((and (consp stepper) (eq (car stepper) 'quote))
1695
(loop-warn "Use of QUOTE around stepping function in LOOP will be left verbatim.")
1696
(values `(funcall ,stepper ,listvar) nil))
1697
((and (consp stepper) (eq (car stepper) 'function))
1698
(values (list (cadr stepper) listvar) (cadr stepper)))
1699
(t (values `(funcall ,(loop-make-variable (loop-gentemp 'loop-fn-) stepper 'function)
1704
(defun loop-for-on (var val data-type)
1705
(multiple-value-bind (list constantp list-value) (loop-constant-fold-if-possible val)
1706
(let ((listvar var))
1707
(cond ((and var (symbolp var)) (loop-make-iteration-variable var list data-type))
1708
(t (loop-make-variable (setq listvar (loop-gentemp)) list 'list)
1709
(loop-make-iteration-variable var nil data-type)))
1710
(multiple-value-bind (list-step step-function) (loop-list-step listvar)
1711
(declare #+(and (not LOOP-Prefer-POP) (not CLOE)) (ignore step-function))
1712
;;@@@@ The CLOE problem above has to do with bug in macroexpansion of multiple-value-bind.
1713
(let* ((first-endtest
1714
(hide-variable-reference
1717
;; the following should use `atom' instead of `endp', per
1720
(other-endtest first-endtest))
1721
(when (and constantp (listp list-value))
1722
(setq first-endtest (null list-value)))
1723
(cond ((eq var listvar)
1724
;;Contour of the loop is different because we use the user's variable...
1725
`(() (,listvar ,(hide-variable-reference t listvar list-step)) ,other-endtest
1726
() () () ,first-endtest ()))
1729
(let ((n (cdr (assoc step-function '((cdr . 1) (cddr . 2)
1730
(cdddr . 3) (cddddr . 4))))))
1731
(and n (do ((l var (cdr l)) (i 0 (1+ i)))
1732
((atom l) (and (null l) (= i n)))
1733
(declare (fixnum i))))))
1734
(let ((step (mapcan #'(lambda (x) (list x `(pop ,listvar))) var)))
1735
`(,other-endtest () () ,step ,first-endtest () () ,step)))
1736
(t (let ((step `(,var ,listvar)) (pseudo `(,listvar ,list-step)))
1737
`(,other-endtest ,step () ,pseudo
1738
,@(and (not (eq first-endtest other-endtest))
1739
`(,first-endtest ,step () ,pseudo)))))))))))
1742
(defun loop-for-in (var val data-type)
1743
(multiple-value-bind (list constantp list-value) (loop-constant-fold-if-possible val)
1744
(let ((listvar (loop-gentemp 'loop-list-)))
1745
(loop-make-iteration-variable var nil data-type)
1746
(loop-make-variable listvar list 'list)
1747
(multiple-value-bind (list-step step-function) (loop-list-step listvar)
1748
#-LOOP-Prefer-POP (declare (ignore step-function))
1749
(let* ((first-endtest `(endp ,listvar))
1750
(other-endtest first-endtest)
1751
(step `(,var (car ,listvar)))
1752
(pseudo-step `(,listvar ,list-step)))
1753
(when (and constantp (listp list-value))
1754
(setq first-endtest (null list-value)))
1755
#+LOOP-Prefer-POP (when (eq step-function 'cdr)
1756
(setq step `(,var (pop ,listvar)) pseudo-step nil))
1757
`(,other-endtest ,step () ,pseudo-step
1758
,@(and (not (eq first-endtest other-endtest))
1759
`(,first-endtest ,step () ,pseudo-step))))))))
1762
;;;; Iteration Paths
1765
(defstruct (loop-path
1775
(defun add-loop-path (names function universe &key preposition-groups inclusive-permitted user-data)
1776
(unless (listp names) (setq names (list names)))
1777
;; Can't do this due to CLOS bootstrapping problems.
1778
#-(or Genera (and CLOE Source-Bootstrap)) (check-type universe loop-universe)
1779
(let ((ht (loop-universe-path-keywords universe))
1781
:names (mapcar #'symbol-name names)
1783
:user-data user-data
1784
:preposition-groups (mapcar #'(lambda (x) (if (listp x) x (list x))) preposition-groups)
1785
:inclusive-permitted inclusive-permitted)))
1786
(dolist (name names) (setf (gethash (symbol-name name) ht) lp))
1790
;;; Note: path functions are allowed to use loop-make-variable, hack
1791
;;; the prologue, etc.
1792
(defun loop-for-being (var val data-type)
1793
;; FOR var BEING each/the pathname prep-phrases using-stuff...
1794
;; each/the = EACH or THE. Not clear if it is optional, so I guess we'll warn.
1799
(initial-prepositions nil))
1800
(cond ((loop-tmember val '(:each :the)) (setq path (loop-pop-source)))
1801
((loop-tequal (car *loop-source-code*) :and)
1804
(unless (loop-tmember (car *loop-source-code*) '(:its :each :his :her))
1805
(loop-error "~S found where ITS or EACH expected in LOOP iteration path syntax."
1806
(car *loop-source-code*)))
1808
(setq path (loop-pop-source))
1809
(setq initial-prepositions `((:in ,val))))
1810
(t (loop-error "Unrecognizable LOOP iteration path syntax. Missing EACH or THE?")))
1811
(cond ((not (symbolp path))
1812
(loop-error "~S found where a LOOP iteration path name was expected." path))
1813
((not (setq data (loop-lookup-keyword path (loop-universe-path-keywords *loop-universe*))))
1814
(loop-error "~S is not the name of a LOOP iteration path." path))
1815
((and inclusive (not (loop-path-inclusive-permitted data)))
1816
(loop-error "\"Inclusive\" iteration is not possible with the ~S LOOP iteration path." path)))
1817
(let ((fun (loop-path-function data))
1818
(preps (nconc initial-prepositions
1819
(loop-collect-prepositional-phrases (loop-path-preposition-groups data) t)))
1820
(user-data (loop-path-user-data data)))
1821
(when (symbolp fun) (setq fun (symbol-function fun)))
1822
(setq stuff (if inclusive
1823
(apply fun var data-type preps :inclusive t user-data)
1824
(apply fun var data-type preps user-data))))
1825
(when *loop-named-variables*
1826
(loop-error "Unused USING variables: ~S." *loop-named-variables*))
1827
;; STUFF is now (bindings prologue-forms . stuff-to-pass-back). Protect the system from the user
1828
;; and the user from himself.
1829
(unless (member (length stuff) '(6 10))
1830
(loop-error "Value passed back by LOOP iteration path function for path ~S has invalid length."
1832
(do ((l (car stuff) (cdr l)) (x)) ((null l))
1833
(if (atom (setq x (car l)))
1834
(loop-make-iteration-variable x nil nil)
1835
(loop-make-iteration-variable (car x) (cadr x) (caddr x))))
1836
(setq *loop-prologue* (nconc (reverse (cadr stuff)) *loop-prologue*))
1841
;;;INTERFACE: Lucid, exported.
1842
;;; i.e., this is part of our extended ansi-loop interface.
1843
(defun named-variable (name)
1844
(let ((tem (loop-tassoc name *loop-named-variables*)))
1845
(declare (list tem))
1846
(cond ((null tem) (values (loop-gentemp) nil))
1847
(t (setq *loop-named-variables* (delete tem *loop-named-variables*))
1848
(values (cdr tem) t)))))
1851
(defun loop-collect-prepositional-phrases (preposition-groups &optional USING-allowed initial-phrases)
1852
(flet ((in-group-p (x group) (car (loop-tmember x group))))
1854
(prepositional-phrases initial-phrases)
1855
(this-group nil nil)
1857
(disallowed-prepositions
1858
(mapcan #'(lambda (x)
1860
(find (car x) preposition-groups :test #'in-group-p)))
1862
(used-prepositions (mapcar #'car initial-phrases)))
1863
((null *loop-source-code*) (nreverse prepositional-phrases))
1864
(declare (symbol this-prep))
1865
(setq token (car *loop-source-code*))
1866
(dolist (group preposition-groups)
1867
(when (setq this-prep (in-group-p token group))
1868
(return (setq this-group group))))
1870
(when (member this-prep disallowed-prepositions)
1872
(if (member this-prep used-prepositions)
1873
"A ~S prepositional phrase occurs multiply for some LOOP clause."
1874
"Preposition ~S used when some other preposition has subsumed it.")
1876
(setq used-prepositions (if (listp this-group)
1877
(append this-group used-prepositions)
1878
(cons this-group used-prepositions)))
1880
(push (list this-prep (loop-get-form)) prepositional-phrases))
1881
((and USING-allowed (loop-tequal token 'using))
1883
(do ((z (loop-pop-source) (loop-pop-source)) (tem)) (nil)
1885
(if (setq tem (loop-tassoc (car z) *loop-named-variables*))
1887
"The variable substitution for ~S occurs twice in a USING phrase,~@
1889
(car z) (cadr z) (cadr tem))
1890
(push (cons (car z) (cadr z)) *loop-named-variables*)))
1891
(when (or (null *loop-source-code*) (symbolp (car *loop-source-code*)))
1893
(t (return (nreverse prepositional-phrases)))))))
1896
;;;; Master Sequencer Function
1899
(defun loop-sequencer (indexv indexv-type indexv-user-specified-p
1900
variable variable-type
1901
sequence-variable sequence-type
1902
step-hack default-top
1904
(let ((endform nil) ;Form (constant or variable) with limit value.
1905
(sequencep nil) ;T if sequence arg has been provided.
1906
(testfn nil) ;endtest function
1907
(test nil) ;endtest form.
1908
(stepby (1+ (or (loop-typed-init indexv-type) 0))) ;Our increment.
1909
(stepby-constantp t)
1910
(step nil) ;step form.
1911
(dir nil) ;Direction of stepping: NIL, :UP, :DOWN.
1912
(inclusive-iteration nil) ;T if include last index.
1913
(start-given nil) ;T when prep phrase has specified start
1915
(start-constantp nil)
1916
(limit-given nil) ;T when prep phrase has specified end
1917
(limit-constantp nil)
1920
(when variable (loop-make-iteration-variable variable nil variable-type))
1921
(do ((l prep-phrases (cdr l)) (prep) (form) (odir)) ((null l))
1922
(setq prep (caar l) form (cadar l))
1926
(loop-make-variable sequence-variable form sequence-type))
1927
((:from :downfrom :upfrom)
1928
(setq start-given t)
1929
(cond ((eq prep :downfrom) (setq dir ':down))
1930
((eq prep :upfrom) (setq dir ':up)))
1931
(multiple-value-setq (form start-constantp start-value)
1932
(loop-constant-fold-if-possible form indexv-type))
1933
(loop-make-iteration-variable indexv form indexv-type))
1934
((:upto :to :downto :above :below)
1935
(cond ((loop-tequal prep :upto) (setq inclusive-iteration (setq dir ':up)))
1936
((loop-tequal prep :to) (setq inclusive-iteration t))
1937
((loop-tequal prep :downto) (setq inclusive-iteration (setq dir ':down)))
1938
((loop-tequal prep :above) (setq dir ':down))
1939
((loop-tequal prep :below) (setq dir ':up)))
1940
(setq limit-given t)
1941
(multiple-value-setq (form limit-constantp limit-value)
1942
(loop-constant-fold-if-possible form indexv-type))
1943
(setq endform (if limit-constantp
1946
(loop-gentemp 'loop-limit-) form indexv-type))))
1948
(multiple-value-setq (form stepby-constantp stepby)
1949
(loop-constant-fold-if-possible form indexv-type))
1950
(unless stepby-constantp
1951
(loop-make-variable (setq stepby (loop-gentemp 'loop-step-by-)) form indexv-type)))
1953
"~S invalid preposition in sequencing or sequence path.~@
1954
Invalid prepositions specified in iteration path descriptor or something?"
1956
(when (and odir dir (not (eq dir odir)))
1957
(loop-error "Conflicting stepping directions in LOOP sequencing path"))
1959
(when (and sequence-variable (not sequencep))
1960
(loop-error "Missing OF or IN phrase in sequence path"))
1961
;; Now fill in the defaults.
1963
(loop-make-iteration-variable
1965
(setq start-constantp t start-value (or (loop-typed-init indexv-type) 0))
1967
(cond ((member dir '(nil :up))
1968
(when (or limit-given default-top)
1970
(loop-make-variable (setq endform (loop-gentemp 'loop-seq-limit-))
1972
(push `(setq ,endform ,default-top) *loop-prologue*))
1973
(setq testfn (if inclusive-iteration '> '>=)))
1974
(setq step (if (eql stepby 1) `(1+ ,indexv) `(+ ,indexv ,stepby))))
1975
(t (unless start-given
1977
(loop-error "Don't know where to start stepping."))
1978
(push `(setq ,indexv (1- ,default-top)) *loop-prologue*))
1979
(when (and default-top (not endform))
1980
(setq endform (loop-typed-init indexv-type) inclusive-iteration t))
1981
(when endform (setq testfn (if inclusive-iteration '< '<=)))
1982
(setq step (if (eql stepby 1) `(1- ,indexv) `(- ,indexv ,stepby)))))
1983
(when testfn (setq test (hide-variable-reference t indexv `(,testfn ,indexv ,endform))))
1985
(setq step-hack `(,variable ,(hide-variable-reference indexv-user-specified-p indexv step-hack))))
1986
(let ((first-test test) (remaining-tests test))
1987
(when (and stepby-constantp start-constantp limit-constantp)
1988
(when (setq first-test (funcall (symbol-function testfn) start-value limit-value))
1989
(setq remaining-tests t)))
1990
`(() (,indexv ,(hide-variable-reference t indexv step)) ,remaining-tests ,step-hack
1991
() () ,first-test ,step-hack))))
1994
;;;; Interfaces to the Master Sequencer
1998
(defun loop-for-arithmetic (var val data-type kwd)
2000
var (loop-check-data-type data-type *loop-real-data-type*) t
2001
nil nil nil nil nil nil
2002
(loop-collect-prepositional-phrases
2003
'((:from :upfrom :downfrom) (:to :upto :downto :above :below) (:by))
2004
nil (list (list kwd val)))))
2007
(defun loop-sequence-elements-path (variable data-type prep-phrases
2008
&key fetch-function size-function sequence-type element-type)
2009
(multiple-value-bind (indexv indexv-user-specified-p) (named-variable 'index)
2010
(let ((sequencev (named-variable 'sequence)))
2011
#+Genera (when (and sequencev
2014
(subtypep sequence-type 'vector)
2015
(not (member (the symbol sequencev) *loop-nodeclare*)))
2016
(push `(sys:array-register ,sequencev) *loop-declarations*))
2017
(list* nil nil ; dummy bindings and prologue
2019
indexv 'fixnum indexv-user-specified-p
2020
variable (or data-type element-type)
2021
sequencev sequence-type
2022
`(,fetch-function ,sequencev ,indexv) `(,size-function ,sequencev)
2026
;;;; Builtin LOOP Iteration Paths
2030
(loop for v being the hash-values of ht do (print v))
2031
(loop for k being the hash-keys of ht do (print k))
2032
(loop for v being the hash-values of ht using (hash-key k) do (print (list k v)))
2033
(loop for k being the hash-keys of ht using (hash-value v) do (print (list k v)))
2036
(defun loop-hash-table-iteration-path (variable data-type prep-phrases &key which)
2037
(check-type which (member hash-key hash-value))
2038
(cond ((or (cdr prep-phrases) (not (member (caar prep-phrases) '(:in :of))))
2039
(loop-error "Too many prepositions!"))
2040
((null prep-phrases) (loop-error "Missing OF or IN in ~S iteration path.")))
2041
(let ((ht-var (loop-gentemp 'loop-hashtab-))
2042
(next-fn (loop-gentemp 'loop-hashtab-next-))
2043
(dummy-predicate-var nil)
2045
(multiple-value-bind (other-var other-p)
2046
(named-variable (if (eq which 'hash-key) 'hash-value 'hash-key))
2047
;;@@@@ named-variable returns a second value of T if the name was actually
2048
;; specified, so clever code can throw away the gensym'ed up variable if
2049
;; it isn't really needed.
2050
;;The following is for those implementations in which we cannot put dummy NILs
2051
;; into multiple-value-setq variable lists.
2052
#-Genera (setq other-p t
2053
dummy-predicate-var (loop-when-it-variable))
2054
(let* ((key-var nil)
2056
(temp-val-var (loop-gentemp 'loop-hash-val-temp-))
2057
(temp-key-var (loop-gentemp 'loop-hash-key-temp-))
2058
(temp-predicate-var (loop-gentemp 'loop-hash-predicate-var-))
2059
(variable (or variable (loop-gentemp)))
2060
(bindings `((,variable nil ,data-type)
2061
(,ht-var ,(cadar prep-phrases))
2062
,@(and other-p other-var `((,other-var nil))))))
2063
(if (eq which 'hash-key)
2064
(setq key-var variable val-var (and other-p other-var))
2065
(setq key-var (and other-p other-var) val-var variable))
2066
(push `(with-hash-table-iterator (,next-fn ,ht-var)) *loop-wrappers*)
2067
(when (consp key-var)
2068
(setq post-steps `(,key-var ,(setq key-var (loop-gentemp 'loop-hash-key-temp-))
2070
(push `(,key-var nil) bindings))
2071
(when (consp val-var)
2072
(setq post-steps `(,val-var ,(setq val-var (loop-gentemp 'loop-hash-val-temp-))
2074
(push `(,val-var nil) bindings))
2075
`(,bindings ;bindings
2080
(multiple-value-bind (,temp-predicate-var ,temp-key-var ,temp-val-var)
2082
;; We use M-V-BIND instead of M-V-SETQ because we only
2083
;; want to assign values to the key and val vars when we
2084
;; are in the hash table. When we reach the end,
2085
;; TEMP-PREDICATE-VAR is NIL, and so are temp-key-var and
2086
;; temp-val-var. This might break any type declarations
2087
;; on the key and val vars.
2088
(when ,temp-predicate-var
2089
(setq ,val-var ,temp-val-var)
2090
(setq ,key-var ,temp-key-var))
2091
(setq ,dummy-predicate-var ,temp-predicate-var)
2096
(defun loop-package-symbols-iteration-path (variable data-type prep-phrases &key symbol-types)
2097
(cond ((and prep-phrases (cdr prep-phrases))
2098
(loop-error "Too many prepositions!"))
2099
((and prep-phrases (not (member (caar prep-phrases) '(:in :of))))
2100
(loop-error "Unknow preposition ~S" (caar prep-phrases))))
2101
(unless (symbolp variable)
2102
(loop-error "Destructuring is not valid for package symbol iteration."))
2103
(let ((pkg-var (loop-gentemp 'loop-pkgsym-))
2104
(next-fn (loop-gentemp 'loop-pkgsym-next-))
2105
(variable (or variable (loop-gentemp)))
2106
(pkg (or (cadar prep-phrases) '*package*)))
2107
(push `(with-package-iterator (,next-fn ,pkg-var ,@symbol-types)) *loop-wrappers*)
2108
`(((,variable nil ,data-type) (,pkg-var ,pkg))
2112
(not (multiple-value-setq (,(progn
2113
;;@@@@ If an implementation can get away without actually
2114
;; using a variable here, so much the better.
2116
#-Genera (loop-when-it-variable))
2123
(defun make-ansi-loop-universe (extended-p)
2124
(let ((w (make-standard-loop-universe
2125
:keywords `((named (loop-do-named))
2126
(initially (loop-do-initially))
2127
(finally (loop-do-finally))
2129
(doing (loop-do-do))
2130
(return (loop-do-return))
2131
(collect (loop-list-collection list))
2132
(collecting (loop-list-collection list))
2133
(append (loop-list-collection append))
2134
(appending (loop-list-collection append))
2135
(nconc (loop-list-collection nconc))
2136
(nconcing (loop-list-collection nconc))
2137
(count (loop-sum-collection count ,*loop-real-data-type* fixnum))
2138
(counting (loop-sum-collection count ,*loop-real-data-type* fixnum))
2139
(sum (loop-sum-collection sum number number))
2140
(summing (loop-sum-collection sum number number))
2141
(maximize (loop-maxmin-collection max))
2142
(minimize (loop-maxmin-collection min))
2143
(maximizing (loop-maxmin-collection max))
2144
(minimizing (loop-maxmin-collection min))
2145
(always (loop-do-always t nil)) ; Normal, do always
2146
(never (loop-do-always t t)) ; Negate the test on always.
2147
(thereis (loop-do-thereis t))
2148
(while (loop-do-while nil :while)) ; Normal, do while
2149
(until (loop-do-while t :until)) ; Negate the test on while
2150
(when (loop-do-if when nil)) ; Normal, do when
2151
(if (loop-do-if if nil)) ; synonymous
2152
(unless (loop-do-if unless t)) ; Negate the test on when
2153
(with (loop-do-with))
2154
(repeat (loop-do-repeat)))
2155
:for-keywords '((= (loop-ansi-for-equals))
2156
(across (loop-for-across))
2159
(from (loop-for-arithmetic :from))
2160
(downfrom (loop-for-arithmetic :downfrom))
2161
(upfrom (loop-for-arithmetic :upfrom))
2162
(below (loop-for-arithmetic :below))
2163
(above (loop-for-arithmetic :above))
2164
(to (loop-for-arithmetic :to))
2165
(upto (loop-for-arithmetic :upto))
2166
(downto (loop-for-arithmetic :downto))
2167
(by (loop-for-arithmetic :by))
2168
(being (loop-for-being)))
2169
:iteration-keywords '((for (loop-do-for))
2171
:type-symbols '(array atom bignum bit bit-vector character compiled-function
2172
complex cons double-float fixnum float
2173
function hash-table integer keyword list long-float
2174
nil null number package pathname random-state
2175
ratio rational readtable sequence short-float
2176
simple-array simple-bit-vector simple-string
2177
simple-vector single-float standard-char
2178
stream string base-char
2181
:ansi (if extended-p :extended t))))
2182
(add-loop-path '(hash-key hash-keys) 'loop-hash-table-iteration-path w
2183
:preposition-groups '((:of :in))
2184
:inclusive-permitted nil
2185
:user-data '(:which hash-key))
2186
(add-loop-path '(hash-value hash-values) 'loop-hash-table-iteration-path w
2187
:preposition-groups '((:of :in))
2188
:inclusive-permitted nil
2189
:user-data '(:which hash-value))
2190
(add-loop-path '(symbol symbols) 'loop-package-symbols-iteration-path w
2191
:preposition-groups '((:of :in))
2192
:inclusive-permitted nil
2193
:user-data '(:symbol-types (:internal :external :inherited)))
2194
(add-loop-path '(external-symbol external-symbols) 'loop-package-symbols-iteration-path w
2195
:preposition-groups '((:of :in))
2196
:inclusive-permitted nil
2197
:user-data '(:symbol-types (:external)))
2198
(add-loop-path '(present-symbol present-symbols) 'loop-package-symbols-iteration-path w
2199
:preposition-groups '((:of :in))
2200
:inclusive-permitted nil
2201
:user-data '(:symbol-types (:internal :external)))
2205
(defparameter *loop-ansi-universe*
2206
(make-ansi-loop-universe nil))
2209
(defun loop-standard-expansion (keywords-and-forms environment universe)
2210
(if (and keywords-and-forms (symbolp (car keywords-and-forms)))
2211
(loop-translate keywords-and-forms environment universe)
2212
(let ((tag (gensym)))
2213
`(block nil (tagbody ,tag (progn ,@keywords-and-forms) (go ,tag))))))
2217
(defmacro loop (&environment env &rest keywords-and-forms)
2218
#+Genera (declare (compiler:do-not-record-macroexpansions)
2219
(zwei:indentation . zwei:indent-loop))
2220
(loop-standard-expansion keywords-and-forms env *loop-ansi-universe*))
2223
(defun excl::complex-loop-expander (body env)
2224
(loop-standard-expansion body env *loop-ansi-universe*))
added
removed
mod/gcl_loop.lsp
