From 1f8ca5e8ebabfe26c8c1839475145c99f08822b8 Mon Sep 17 00:00:00 2001 From: Jim Blandy Date: Thu, 7 Feb 1991 19:57:33 +0000 Subject: [PATCH] Initial revision --- lisp/cl.el | 3137 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 3137 insertions(+) create mode 100644 lisp/cl.el diff --git a/lisp/cl.el b/lisp/cl.el new file mode 100644 index 00000000000..a4386f3c8bb --- /dev/null +++ b/lisp/cl.el @@ -0,0 +1,3137 @@ +;; Common-Lisp extensions for GNU Emacs Lisp. +;; Copyright (C) 1987, 1988, 1989 Free Software Foundation, Inc. + +;; This file is part of GNU Emacs. + +;; GNU Emacs is distributed in the hope that it will be useful, +;; but WITHOUT ANY WARRANTY. No author or distributor +;; accepts responsibility to anyone for the consequences of using it +;; or for whether it serves any particular purpose or works at all, +;; unless he says so in writing. Refer to the GNU Emacs General Public +;; License for full details. + +;; Everyone is granted permission to copy, modify and redistribute +;; GNU Emacs, but only under the conditions described in the +;; GNU Emacs General Public License. A copy of this license is +;; supposed to have been given to you along with GNU Emacs so you +;; can know your rights and responsibilities. It should be in a +;; file named COPYING. Among other things, the copyright notice +;; and this notice must be preserved on all copies. + +;;;; +;;;; These are extensions to Emacs Lisp that provide some form of +;;;; Common Lisp compatibility, beyond what is already built-in +;;;; in Emacs Lisp. +;;;; +;;;; When developing them, I had the code spread among several files. +;;;; This file 'cl.el' is a concatenation of those original files, +;;;; minus some declarations that became redundant. The marks between +;;;; the original files can be found easily, as they are lines that +;;;; begin with four semicolons (as this does). The names of the +;;;; original parts follow the four semicolons in uppercase, those +;;;; names are GLOBAL, SYMBOLS, LISTS, SEQUENCES, CONDITIONALS, +;;;; ITERATIONS, MULTIPLE VALUES, ARITH, SETF and DEFSTRUCT. If you +;;;; add functions to this file, you might want to put them in a place +;;;; that is compatible with the division above (or invent your own +;;;; categories). +;;;; +;;;; To compile this file, make sure you load it first. This is +;;;; because many things are implemented as macros and now that all +;;;; the files are concatenated together one cannot ensure that +;;;; declaration always precedes use. +;;;; +;;;; Bug reports, suggestions and comments, +;;;; to quiroz@cs.rochester.edu + +(provide 'cl) +(defvar cl-version "2.0 beta 29 October 1989") + + +;;;; GLOBAL +;;;; This file provides utilities and declarations that are global +;;;; to Common Lisp and so might be used by more than one of the +;;;; other libraries. Especially, I intend to keep here some +;;;; utilities that help parsing/destructuring some difficult calls. +;;;; +;;;; +;;;; Cesar Quiroz @ UofR DofCSc - Dec. 1986 +;;;; (quiroz@cs.rochester.edu) + +;;; Too many pieces of the rest of this package use psetq. So it is unwise to +;;; use here anything but plain Emacs Lisp! There is a neater recursive form +;;; for the algorithm that deals with the bodies. + +(defmacro psetq (&rest body) + "(psetq {var value }...) => nil +Like setq, but all the values are computed before any assignment is made." + (let ((length (length body))) + (cond ((/= (% length 2) 0) + (error "psetq needs an even number of arguments, %d given" + length)) + ((null body) + '()) + (t + (list 'prog1 nil + (let ((setqs '()) + (bodyforms (reverse body))) + (while bodyforms + (let* ((value (car bodyforms)) + (place (cadr bodyforms))) + (setq bodyforms (cddr bodyforms)) + (if (null setqs) + (setq setqs (list 'setq place value)) + (setq setqs (list 'setq place + (list 'prog1 value + setqs)))))) + setqs)))))) + +;;; utilities +;;; +;;; pair-with-newsyms takes a list and returns a list of lists of the +;;; form (newsym form), such that a let* can then bind the evaluation +;;; of the forms to the newsyms. The idea is to guarantee correct +;;; order of evaluation of the subforms of a setf. It also returns a +;;; list of the newsyms generated, in the corresponding order. + +(defun pair-with-newsyms (oldforms) + "PAIR-WITH-NEWSYMS OLDFORMS +The top-level components of the list oldforms are paired with fresh +symbols, the pairings list and the newsyms list are returned." + (do ((ptr oldforms (cdr ptr)) + (bindings '()) + (newsyms '())) + ((endp ptr) (values (nreverse bindings) (nreverse newsyms))) + (let ((newsym (gentemp))) + (setq bindings (cons (list newsym (car ptr)) bindings)) + (setq newsyms (cons newsym newsyms))))) + +(defun zip-lists (evens odds) + "Merge two lists EVENS and ODDS, taking elts from each list alternatingly. +EVENS and ODDS are two lists. ZIP-LISTS constructs a new list, whose +even numbered elements (0,2,...) come from EVENS and whose odd numbered +elements (1,3,...) come from ODDS. +The construction stops when the shorter list is exhausted." + (do* ((p0 evens (cdr p0)) + (p1 odds (cdr p1)) + (even (car p0) (car p0)) + (odd (car p1) (car p1)) + (result '())) + ((or (endp p0) (endp p1)) + (nreverse result)) + (setq result + (cons odd (cons even result))))) + +(defun unzip-list (list) + "Extract even and odd elements of LIST into two separate lists. +The argument LIST is separated in two strands, the even and the odd +numbered elements. Numbering starts with 0, so the first element +belongs in EVENS. No check is made that there is an even number of +elements to start with." + (do* ((ptr list (cddr ptr)) + (this (car ptr) (car ptr)) + (next (cadr ptr) (cadr ptr)) + (evens '()) + (odds '())) + ((endp ptr) + (values (nreverse evens) (nreverse odds))) + (setq evens (cons this evens)) + (setq odds (cons next odds)))) + +(defun reassemble-argslists (argslists) + "(reassemble-argslists ARGSLISTS) => a list of lists +ARGSLISTS is a list of sequences. Return a list of lists, the first +sublist being all the entries coming from ELT 0 of the original +sublists, the next those coming from ELT 1 and so on, until the +shortest list is exhausted." + (let* ((minlen (apply 'min (mapcar 'length argslists))) + (result '())) + (dotimes (i minlen (nreverse result)) + ;; capture all the elements at index i + (setq result + (cons (mapcar (function (lambda (sublist) (elt sublist i))) + argslists) + result))))) + + +;;; Checking that a list of symbols contains no duplicates is a common +;;; task when checking the legality of some macros. The check for 'eq +;;; pairs can be too expensive, as it is quadratic on the length of +;;; the list. I use a 4-pass, linear, counting approach. It surely +;;; loses on small lists (less than 5 elements?), but should win for +;;; larger lists. The fourth pass could be eliminated. +;;; 10 dec 1986. Emacs Lisp has no REMPROP, so I just eliminated the +;;; 4th pass. +(defun duplicate-symbols-p (list) + "Find all symbols appearing more than once in LIST. +Return a list of all such duplicates; nil if there are no duplicates." + (let ((duplicates '()) ;result built here + (propname (gensym)) ;we use a fresh property + ) + ;; check validity + (unless (and (listp list) + (every 'symbolp list)) + (error "a list of symbols is needed")) + ;; pass 1: mark + (dolist (x list) + (put x propname 0)) + ;; pass 2: count + (dolist (x list) + (put x propname (1+ (get x propname)))) + ;; pass 3: collect + (dolist (x list) + (if (> (get x propname) 1) + (setq duplicates (cons x duplicates)))) + ;; pass 4: unmark. eliminated. + ;; (dolist (x list) (remprop x propname)) + ;; return result + duplicates)) + +;;;; end of cl-global.el + +;;;; SYMBOLS +;;;; This file provides the gentemp function, which generates fresh +;;;; symbols, plus some other minor Common Lisp symbol tools. +;;;; +;;;; Cesar Quiroz @ UofR DofCSc - Dec. 1986 +;;;; (quiroz@cs.rochester.edu) + +;;; Keywords. There are no packages in Emacs Lisp, so this is only a +;;; kludge around to let things be "as if" a keyword package was around. + +(defmacro defkeyword (x &optional docstring) + "Make symbol X a keyword (symbol whose value is itself). +Optional second arg DOCSTRING is a documentation string for it." + (cond ((symbolp x) + (list 'defconst x (list 'quote x) docstring)) + (t + (error "`%s' is not a symbol" (prin1-to-string x))))) + +(defun keywordp (sym) + "Return t if SYM is a keyword." + (if (and (symbolp sym) (char-equal (aref (symbol-name sym) 0) ?\:)) + ;; looks like one, make sure value is right + (set sym sym) + nil)) + +(defun keyword-of (sym) + "Return a keyword that is naturally associated with symbol SYM. +If SYM is keyword, the value is SYM. +Otherwise it is a keyword whose name is `:' followed by SYM's name." + (cond ((keywordp sym) + sym) + ((symbolp sym) + (let ((newsym (intern (concat ":" (symbol-name sym))))) + (set newsym newsym))) + (t + (error "expected a symbol, not `%s'" (prin1-to-string sym))))) + +;;; Temporary symbols. +;;; + +(defvar *gentemp-index* 0 + "Integer used by `gentemp' to produce new names.") + +(defvar *gentemp-prefix* "T$$_" + "Names generated by `gentemp begin' with this string by default.") + +(defun gentemp (&optional prefix oblist) + "Generate a fresh interned symbol. +There are two optional arguments, PREFIX and OBLIST. PREFIX is the string +that begins the new name, OBLIST is the obarray used to search for old +names. The defaults are just right, YOU SHOULD NEVER NEED THESE ARGUMENTS +IN YOUR OWN CODE." + (if (null prefix) + (setq prefix *gentemp-prefix*)) + (if (null oblist) + (setq oblist obarray)) ;default for the intern functions + (let ((newsymbol nil) + (newname)) + (while (not newsymbol) + (setq newname (concat prefix *gentemp-index*)) + (setq *gentemp-index* (+ *gentemp-index* 1)) + (if (not (intern-soft newname oblist)) + (setq newsymbol (intern newname oblist)))) + newsymbol)) + +(defvar *gensym-index* 0 + "Integer used by `gensym' to produce new names.") + +(defvar *gensym-prefix* "G$$_" + "Names generated by `gensym' begin with this string by default.") + +(defun gensym (&optional prefix) + "Generate a fresh uninterned symbol. +Optional arg PREFIX is the string that begins the new name. Most people +take just the default, except when debugging needs suggest otherwise." + (if (null prefix) + (setq prefix *gensym-prefix*)) + (let ((newsymbol nil) + (newname "")) + (while (not newsymbol) + (setq newname (concat prefix *gensym-index*)) + (setq *gensym-index* (+ *gensym-index* 1)) + (if (not (intern-soft newname)) + (setq newsymbol (make-symbol newname)))) + newsymbol)) + +;;;; end of cl-symbols.el + +;;;; CONDITIONALS +;;;; This file provides some of the conditional constructs of +;;;; Common Lisp. Total compatibility is again impossible, as the +;;;; 'if' form is different in both languages, so only a good +;;;; approximation is desired. +;;;; +;;;; Cesar Quiroz @ UofR DofCSc - Dec. 1986 +;;;; (quiroz@cs.rochester.edu) + +;;; indentation info +(put 'case 'lisp-indent-function 1) +(put 'ecase 'lisp-indent-function 1) +(put 'when 'lisp-indent-function 1) +(put 'unless 'lisp-indent-function 1) + +;;; WHEN and UNLESS +;;; These two forms are simplified ifs, with a single branch. + +(defmacro when (condition &rest body) + "(when CONDITION . BODY) => evaluate BODY if CONDITION is true." + (list* 'if (list 'not condition) '() body)) + +(defmacro unless (condition &rest body) + "(unless CONDITION . BODY) => evaluate BODY if CONDITION is false." + (list* 'if condition '() body)) + +;;; CASE and ECASE +;;; CASE selects among several clauses, based on the value (evaluated) +;;; of a expression and a list of (unevaluated) key values. ECASE is +;;; the same, but signals an error if no clause is activated. + +(defmacro case (expr &rest cases) + "(case EXPR . CASES) => evals EXPR, chooses from CASES on that value. +EXPR -> any form +CASES -> list of clauses, non empty +CLAUSE -> HEAD . BODY +HEAD -> t = catch all, must be last clause + -> otherwise = same as t + -> nil = illegal + -> atom = activated if (eql EXPR HEAD) + -> list of atoms = activated if (memq EXPR HEAD) +BODY -> list of forms, implicit PROGN is built around it. +EXPR is evaluated only once." + (let* ((newsym (gentemp)) + (clauses (case-clausify cases newsym))) + ;; convert case into a cond inside a let + (list 'let + (list (list newsym expr)) + (list* 'cond (nreverse clauses))))) + +(defmacro ecase (expr &rest cases) + "(ecase EXPR . CASES) => like `case', but error if no case fits. +`t'-clauses are not allowed." + (let* ((newsym (gentemp)) + (clauses (case-clausify cases newsym))) + ;; check that no 't clause is present. + ;; case-clausify would put one such at the beginning of clauses + (if (eq (caar clauses) t) + (error "no clause-head should be `t' or `otherwise' for `ecase'")) + ;; insert error-catching clause + (setq clauses + (cons + (list 't (list 'error + "ecase on %s = %s failed to take any branch" + (list 'quote expr) + (list 'prin1-to-string newsym))) + clauses)) + ;; generate code as usual + (list 'let + (list (list newsym expr)) + (list* 'cond (nreverse clauses))))) + + +(defun case-clausify (cases newsym) + "CASE-CLAUSIFY CASES NEWSYM => clauses for a 'cond' +Converts the CASES of a [e]case macro into cond clauses to be +evaluated inside a let that binds NEWSYM. Returns the clauses in +reverse order." + (do* ((currentpos cases (cdr currentpos)) + (nextpos (cdr cases) (cdr nextpos)) + (curclause (car cases) (car currentpos)) + (result '())) + ((endp currentpos) result) + (let ((head (car curclause)) + (body (cdr curclause))) + ;; construct a cond-clause according to the head + (cond ((null head) + (error "case clauses cannot have null heads: `%s'" + (prin1-to-string curclause))) + ((or (eq head 't) + (eq head 'otherwise)) + ;; check it is the last clause + (if (not (endp nextpos)) + (error "clause with `t' or `otherwise' head must be last")) + ;; accept this clause as a 't' for cond + (setq result (cons (cons 't body) result))) + ((atom head) + (setq result + (cons (cons (list 'eql newsym (list 'quote head)) body) + result))) + ((listp head) + (setq result + (cons (cons (list 'memq newsym (list 'quote head)) body) + result))) + (t + ;; catch-all for this parser + (error "don't know how to parse case clause `%s'" + (prin1-to-string head))))))) + +;;;; end of cl-conditionals.el + +;;;; ITERATIONS +;;;; This file provides simple iterative macros (a la Common Lisp) +;;;; constructed on the basis of let, let* and while, which are the +;;;; primitive binding/iteration constructs of Emacs Lisp +;;;; +;;;; The Common Lisp iterations use to have a block named nil +;;;; wrapped around them, and allow declarations at the beginning +;;;; of their bodies and you can return a value using (return ...). +;;;; Nothing of the sort exists in Emacs Lisp, so I haven't tried +;;;; to imitate these behaviors. +;;;; +;;;; Other than the above, the semantics of Common Lisp are +;;;; correctly reproduced to the extent this was reasonable. +;;;; +;;;; Cesar Quiroz @ UofR DofCSc - Dec. 1986 +;;;; (quiroz@cs.rochester.edu) + +;;; some lisp-indentation information +(put 'do 'lisp-indent-function 2) +(put 'do* 'lisp-indent-function 2) +(put 'dolist 'lisp-indent-function 1) +(put 'dotimes 'lisp-indent-function 1) +(put 'do-symbols 'lisp-indent-function 1) +(put 'do-all-symbols 'lisp-indent-function 1) + + +(defmacro do (stepforms endforms &rest body) + "(do STEPFORMS ENDFORMS . BODY): Iterate BODY, stepping some local +variables. STEPFORMS must be a list of symbols or lists. In the second +case, the lists must start with a symbol and contain up to two more forms. +In the STEPFORMS, a symbol is the same as a (symbol). The other two forms +are the initial value (def. NIL) and the form to step (def. itself). + +The values used by initialization and stepping are computed in parallel. +The ENDFORMS are a list (CONDITION . ENDBODY). If the CONDITION evaluates +to true in any iteration, ENDBODY is evaluated and the last form in it is +returned. + +The BODY (which may be empty) is evaluated at every iteration, with the +symbols of the STEPFORMS bound to the initial or stepped values." + + ;; check the syntax of the macro + (and (check-do-stepforms stepforms) + (check-do-endforms endforms)) + ;; construct emacs-lisp equivalent + (let ((initlist (extract-do-inits stepforms)) + (steplist (extract-do-steps stepforms)) + (endcond (car endforms)) + (endbody (cdr endforms))) + (cons 'let (cons initlist + (cons (cons 'while (cons (list 'not endcond) + (append body steplist))) + (append endbody)))))) + + +(defmacro do* (stepforms endforms &rest body) + "`do*' is to `do' as `let*' is to `let'. +STEPFORMS must be a list of symbols or lists. In the second case, the +lists must start with a symbol and contain up to two more forms. In the +STEPFORMS, a symbol is the same as a (symbol). The other two forms are +the initial value (def. NIL) and the form to step (def. itself). + +Initializations and steppings are done in the sequence they are written. + +The ENDFORMS are a list (CONDITION . ENDBODY). If the CONDITION evaluates +to true in any iteration, ENDBODY is evaluated and the last form in it is +returned. + +The BODY (which may be empty) is evaluated at every iteration, with +the symbols of the STEPFORMS bound to the initial or stepped values." + ;; check the syntax of the macro + (and (check-do-stepforms stepforms) + (check-do-endforms endforms)) + ;; construct emacs-lisp equivalent + (let ((initlist (extract-do-inits stepforms)) + (steplist (extract-do*-steps stepforms)) + (endcond (car endforms)) + (endbody (cdr endforms))) + (cons 'let* (cons initlist + (cons (cons 'while (cons (list 'not endcond) + (append body steplist))) + (append endbody)))))) + + +;;; DO and DO* share the syntax checking functions that follow. + +(defun check-do-stepforms (forms) + "True if FORMS is a valid stepforms for the do[*] macro (q.v.)" + (if (nlistp forms) + (error "init/step form for do[*] should be a list, not `%s'" + (prin1-to-string forms)) + (mapcar + (function + (lambda (entry) + (if (not (or (symbolp entry) + (and (listp entry) + (symbolp (car entry)) + (< (length entry) 4)))) + (error "init/step must be %s, not `%s'" + "symbol or (symbol [init [step]])" + (prin1-to-string entry))))) + forms))) + +(defun check-do-endforms (forms) + "True if FORMS is a valid endforms for the do[*] macro (q.v.)" + (if (nlistp forms) + (error "termination form for do macro should be a list, not `%s'" + (prin1-to-string forms)))) + +(defun extract-do-inits (forms) + "Returns a list of the initializations (for do) in FORMS +(a stepforms, see the do macro). +FORMS is assumed syntactically valid." + (mapcar + (function + (lambda (entry) + (cond ((symbolp entry) + (list entry nil)) + ((listp entry) + (list (car entry) (cadr entry)))))) + forms)) + +;;; There used to be a reason to deal with DO differently than with +;;; DO*. The writing of PSETQ has made it largely unnecessary. + +(defun extract-do-steps (forms) + "EXTRACT-DO-STEPS FORMS => an s-expr. +FORMS is the stepforms part of a DO macro (q.v.). This function constructs +an s-expression that does the stepping at the end of an iteration." + (list (cons 'psetq (select-stepping-forms forms)))) + +(defun extract-do*-steps (forms) + "EXTRACT-DO*-STEPS FORMS => an s-expr. +FORMS is the stepforms part of a DO* macro (q.v.). This function constructs +an s-expression that does the stepping at the end of an iteration." + (list (cons 'setq (select-stepping-forms forms)))) + +(defun select-stepping-forms (forms) + "Separate only the forms that cause stepping." + (let ((result '()) ;ends up being (... var form ...) + (ptr forms) ;to traverse the forms + entry ;to explore each form in turn + ) + (while ptr ;(not (endp entry)) might be safer + (setq entry (car ptr)) + (cond ((and (listp entry) (= (length entry) 3)) + (setq result (append ;append in reverse order! + (list (caddr entry) (car entry)) + result)))) + (setq ptr (cdr ptr))) ;step in the list of forms + (nreverse result))) + +;;; Other iterative constructs + +(defmacro dolist (stepform &rest body) + "(dolist (VAR LIST [RESULTFORM]) . BODY): do BODY for each elt of LIST. +The RESULTFORM defaults to nil. The VAR is bound to successive elements +of the value of LIST and remains bound (to the nil value) when the +RESULTFORM is evaluated." + ;; check sanity + (cond + ((nlistp stepform) + (error "stepform for `dolist' should be (VAR LIST [RESULT]), not `%s'" + (prin1-to-string stepform))) + ((not (symbolp (car stepform))) + (error "first component of stepform should be a symbol, not `%s'" + (prin1-to-string (car stepform)))) + ((> (length stepform) 3) + (error "too many components in stepform `%s'" + (prin1-to-string stepform)))) + ;; generate code + (let* ((var (car stepform)) + (listform (cadr stepform)) + (resultform (caddr stepform))) + (list 'progn + (list 'mapcar + (list 'function + (cons 'lambda (cons (list var) body))) + listform) + (list 'let + (list (list var nil)) + resultform)))) + +(defmacro dotimes (stepform &rest body) + "(dotimes (VAR COUNTFORM [RESULTFORM]) . BODY): Repeat BODY, counting in VAR. +The COUNTFORM should return a positive integer. The VAR is bound to +successive integers from 0 to COUNTFORM - 1 and the BODY is repeated for +each of them. At the end, the RESULTFORM is evaluated and its value +returned. During this last evaluation, the VAR is still bound, and its +value is the number of times the iteration occurred. An omitted RESULTFORM +defaults to nil." + ;; check sanity + (cond + ((nlistp stepform) + (error "stepform for `dotimes' should be (VAR COUNT [RESULT]), not `%s'" + (prin1-to-string stepform))) + ((not (symbolp (car stepform))) + (error "first component of stepform should be a symbol, not `%s'" + (prin1-to-string (car stepform)))) + ((> (length stepform) 3) + (error "too many components in stepform `%s'" + (prin1-to-string stepform)))) + ;; generate code + (let* ((var (car stepform)) + (countform (cadr stepform)) + (resultform (caddr stepform)) + (newsym (gentemp))) + (list + 'let* (list (list newsym countform)) + (list* + 'do* + (list (list var 0 (list '+ var 1))) + (list (list '>= var newsym) resultform) + body)))) + +(defmacro do-symbols (stepform &rest body) + "(do_symbols (VAR [OBARRAY [RESULTFORM]]) . BODY) +The VAR is bound to each of the symbols in OBARRAY (def. obarray) and +the BODY is repeatedly performed for each of those bindings. At the +end, RESULTFORM (def. nil) is evaluated and its value returned. +During this last evaluation, the VAR is still bound and its value is nil. +See also the function `mapatoms'." + ;; check sanity + (cond + ((nlistp stepform) + (error "stepform for `do-symbols' should be (VAR OBARRAY [RESULT]), not `%s'" + (prin1-to-string stepform))) + ((not (symbolp (car stepform))) + (error "first component of stepform should be a symbol, not `%s'" + (prin1-to-string (car stepform)))) + ((> (length stepform) 3) + (error "too many components in stepform `%s'" + (prin1-to-string stepform)))) + ;; generate code + (let* ((var (car stepform)) + (oblist (cadr stepform)) + (resultform (caddr stepform))) + (list 'progn + (list 'mapatoms + (list 'function + (cons 'lambda (cons (list var) body))) + oblist) + (list 'let + (list (list var nil)) + resultform)))) + + +(defmacro do-all-symbols (stepform &rest body) + "(do-all-symbols (VAR [RESULTFORM]) . BODY) +Is the same as (do-symbols (VAR obarray RESULTFORM) . BODY)." + (list* + 'do-symbols + (list (car stepform) 'obarray (cadr stepform)) + body)) + +(defmacro loop (&rest body) + "(loop . BODY) repeats BODY indefinitely and does not return. +Normally BODY uses `throw' or `signal' to cause an exit. +The forms in BODY should be lists, as non-lists are reserved for new features." + ;; check that the body doesn't have atomic forms + (if (nlistp body) + (error "body of `loop' should be a list of lists or nil") + ;; ok, it is a list, check for atomic components + (mapcar + (function (lambda (component) + (if (nlistp component) + (error "components of `loop' should be lists")))) + body) + ;; build the infinite loop + (cons 'while (cons 't body)))) + +;;;; end of cl-iterations.el + +;;;; LISTS +;;;; This file provides some of the lists machinery of Common-Lisp +;;;; in a way compatible with Emacs Lisp. Especially, see the the +;;;; typical c[ad]*r functions. +;;;; +;;;; Cesar Quiroz @ UofR DofCSc - Dec. 1986 +;;;; (quiroz@cs.rochester.edu) + +(defvar *cl-valid-named-list-accessors* + '(first rest second third fourth fifth sixth seventh eighth ninth tenth)) +(defvar *cl-valid-nth-offsets* + '((second . 1) + (third . 2) + (fourth . 3) + (fifth . 4) + (sixth . 5) + (seventh . 6) + (eighth . 7) + (ninth . 8) + (tenth . 9))) + +(defun byte-compile-named-list-accessors (form) + "Generate code for ( FORM), where is one of the named +list accessors: first, second, ..., tenth, rest." + (let* ((fun (car form)) + (arg (cadr form)) + (valid *cl-valid-named-list-accessors*) + (offsets *cl-valid-nth-offsets*)) + (if (or (null (cdr form)) (cddr form)) + (error "%s needs exactly one argument, seen `%s'" + fun (prin1-to-string form))) + (if (not (memq fun valid)) + (error "`%s' not in {first, ..., tenth, rest}" fun)) + (cond ((eq fun 'first) + (byte-compile-form arg) + (setq byte-compile-depth (1- byte-compile-depth)) + (byte-compile-out byte-car 0)) + ((eq fun 'rest) + (byte-compile-form arg) + (setq byte-compile-depth (1- byte-compile-depth)) + (byte-compile-out byte-cdr 0)) + (t ;one of the others + (byte-compile-constant (cdr (assoc fun offsets))) + (byte-compile-form arg) + (setq byte-compile-depth (1- byte-compile-depth)) + (byte-compile-out byte-nth 0) + )))) + +;;; Synonyms for list functions +(defun first (x) + "Synonym for `car'" + (car x)) +(put 'first 'byte-compile 'byte-compile-named-list-accessors) + +(defun second (x) + "Return the second element of the list LIST." + (nth 1 x)) +(put 'second 'byte-compile 'byte-compile-named-list-accessors) + +(defun third (x) + "Return the third element of the list LIST." + (nth 2 x)) +(put 'third 'byte-compile 'byte-compile-named-list-accessors) + +(defun fourth (x) + "Return the fourth element of the list LIST." + (nth 3 x)) +(put 'fourth 'byte-compile 'byte-compile-named-list-accessors) + +(defun fifth (x) + "Return the fifth element of the list LIST." + (nth 4 x)) +(put 'fifth 'byte-compile 'byte-compile-named-list-accessors) + +(defun sixth (x) + "Return the sixth element of the list LIST." + (nth 5 x)) +(put 'sixth 'byte-compile 'byte-compile-named-list-accessors) + +(defun seventh (x) + "Return the seventh element of the list LIST." + (nth 6 x)) +(put 'seventh 'byte-compile 'byte-compile-named-list-accessors) + +(defun eighth (x) + "Return the eighth element of the list LIST." + (nth 7 x)) +(put 'eighth 'byte-compile 'byte-compile-named-list-accessors) + +(defun ninth (x) + "Return the ninth element of the list LIST." + (nth 8 x)) +(put 'ninth 'byte-compile 'byte-compile-named-list-accessors) + +(defun tenth (x) + "Return the tenth element of the list LIST." + (nth 9 x)) +(put 'tenth 'byte-compile 'byte-compile-named-list-accessors) + +(defun rest (x) + "Synonym for `cdr'" + (cdr x)) +(put 'rest 'byte-compile 'byte-compile-named-list-accessors) + +(defun endp (x) + "t if X is nil, nil if X is a cons; error otherwise." + (if (listp x) + (null x) + (error "endp received a non-cons, non-null argument `%s'" + (prin1-to-string x)))) + +(defun last (x) + "Returns the last link in the list LIST." + (if (nlistp x) + (error "arg to `last' must be a list")) + (do ((current-cons x (cdr current-cons)) + (next-cons (cdr x) (cdr next-cons))) + ((endp next-cons) current-cons))) + +(defun list-length (x) ;taken from CLtL sect. 15.2 + "Returns the length of a non-circular list, or `nil' for a circular one." + (do ((n 0) ;counter + (fast x (cddr fast)) ;fast pointer, leaps by 2 + (slow x (cdr slow)) ;slow pointer, leaps by 1 + (ready nil)) ;indicates termination + (ready n) + (cond ((endp fast) + (setq ready t)) ;return n + ((endp (cdr fast)) + (setq n (+ n 1)) + (setq ready t)) ;return n+1 + ((and (eq fast slow) (> n 0)) + (setq n nil) + (setq ready t)) ;return nil + (t + (setq n (+ n 2)))))) ;just advance counter + +(defun butlast (list &optional n) + "Return a new list like LIST but sans the last N elements. +N defaults to 1. If the list doesn't have N elements, nil is returned." + (if (null n) (setq n 1)) + (reverse (nthcdr n (reverse list)))) + +(defun list* (arg &rest others) + "Return a new list containing the first arguments consed onto the last arg. +Thus, (list* 1 2 3 '(a b)) returns (1 2 3 a b)." + (if (null others) + arg + (let* ((allargs (cons arg others)) + (front (butlast allargs)) + (back (last allargs))) + (rplacd (last front) (car back)) + front))) + +(defun adjoin (item list) + "Return a list which contains ITEM but is otherwise like LIST. +If ITEM occurs in LIST, the value is LIST. Otherwise it is (cons ITEM LIST). +When comparing ITEM against elements, `eql' is used." + (if (memq item list) + list + (cons item list))) + +(defun ldiff (list sublist) + "Return a new list like LIST but sans SUBLIST. +SUBLIST must be one of the links in LIST; otherwise the value is LIST itself." + (do ((result '()) + (curcons list (cdr curcons))) + ((or (endp curcons) (eq curcons sublist)) + (reverse result)) + (setq result (cons (car curcons) result)))) + +;;; The popular c[ad]*r functions and other list accessors. + +;;; To implement this efficiently, a new byte compile handler is used to +;;; generate the minimal code, saving one function call. + +(defun byte-compile-ca*d*r (form) + "Generate code for a (c[ad]+r argument). This realizes the various +combinations of car and cdr whose names are supported in this implementation. +To use this functionality for a given function,just give its name a +'byte-compile property of 'byte-compile-ca*d*r" + (let* ((fun (car form)) + (arg (cadr form)) + (seq (mapcar (function (lambda (letter) + (if (= letter ?a) + 'byte-car 'byte-cdr))) + (cdr (nreverse (cdr (append (symbol-name fun) nil))))))) + ;; SEQ is a list of byte-car and byte-cdr in the correct order. + (if (null seq) + (error "internal: `%s' cannot be compiled by byte-compile-ca*d*r" + (prin1-to-string form))) + (if (or (null (cdr form)) (cddr form)) + (error "%s needs exactly one argument, seen `%s'" + fun (prin1-to-string form))) + (byte-compile-form arg) + (setq byte-compile-depth (1- byte-compile-depth)) + ;; the rest of this code doesn't change the stack depth! + (while seq + (byte-compile-out (car seq) 0) + (setq seq (cdr seq))))) + +(defun caar (X) + "Return the car of the car of X." + (car (car X))) +(put 'caar 'byte-compile 'byte-compile-ca*d*r) + +(defun cadr (X) + "Return the car of the cdr of X." + (car (cdr X))) +(put 'cadr 'byte-compile 'byte-compile-ca*d*r) + +(defun cdar (X) + "Return the cdr of the car of X." + (cdr (car X))) +(put 'cdar 'byte-compile 'byte-compile-ca*d*r) + +(defun cddr (X) + "Return the cdr of the cdr of X." + (cdr (cdr X))) +(put 'cddr 'byte-compile 'byte-compile-ca*d*r) + +(defun caaar (X) + "Return the car of the car of the car of X." + (car (car (car X)))) +(put 'caaar 'byte-compile 'byte-compile-ca*d*r) + +(defun caadr (X) + "Return the car of the car of the cdr of X." + (car (car (cdr X)))) +(put 'caadr 'byte-compile 'byte-compile-ca*d*r) + +(defun cadar (X) + "Return the car of the cdr of the car of X." + (car (cdr (car X)))) +(put 'cadar 'byte-compile 'byte-compile-ca*d*r) + +(defun cdaar (X) + "Return the cdr of the car of the car of X." + (cdr (car (car X)))) +(put 'cdaar 'byte-compile 'byte-compile-ca*d*r) + +(defun caddr (X) + "Return the car of the cdr of the cdr of X." + (car (cdr (cdr X)))) +(put 'caddr 'byte-compile 'byte-compile-ca*d*r) + +(defun cdadr (X) + "Return the cdr of the car of the cdr of X." + (cdr (car (cdr X)))) +(put 'cdadr 'byte-compile 'byte-compile-ca*d*r) + +(defun cddar (X) + "Return the cdr of the cdr of the car of X." + (cdr (cdr (car X)))) +(put 'cddar 'byte-compile 'byte-compile-ca*d*r) + +(defun cdddr (X) + "Return the cdr of the cdr of the cdr of X." + (cdr (cdr (cdr X)))) +(put 'cdddr 'byte-compile 'byte-compile-ca*d*r) + +(defun caaaar (X) + "Return the car of the car of the car of the car of X." + (car (car (car (car X))))) +(put 'caaaar 'byte-compile 'byte-compile-ca*d*r) + +(defun caaadr (X) + "Return the car of the car of the car of the cdr of X." + (car (car (car (cdr X))))) +(put 'caaadr 'byte-compile 'byte-compile-ca*d*r) + +(defun caadar (X) + "Return the car of the car of the cdr of the car of X." + (car (car (cdr (car X))))) +(put 'caadar 'byte-compile 'byte-compile-ca*d*r) + +(defun cadaar (X) + "Return the car of the cdr of the car of the car of X." + (car (cdr (car (car X))))) +(put 'cadaar 'byte-compile 'byte-compile-ca*d*r) + +(defun cdaaar (X) + "Return the cdr of the car of the car of the car of X." + (cdr (car (car (car X))))) +(put 'cdaaar 'byte-compile 'byte-compile-ca*d*r) + +(defun caaddr (X) + "Return the car of the car of the cdr of the cdr of X." + (car (car (cdr (cdr X))))) +(put 'caaddr 'byte-compile 'byte-compile-ca*d*r) + +(defun cadadr (X) + "Return the car of the cdr of the car of the cdr of X." + (car (cdr (car (cdr X))))) +(put 'cadadr 'byte-compile 'byte-compile-ca*d*r) + +(defun cdaadr (X) + "Return the cdr of the car of the car of the cdr of X." + (cdr (car (car (cdr X))))) +(put 'cdaadr 'byte-compile 'byte-compile-ca*d*r) + +(defun caddar (X) + "Return the car of the cdr of the cdr of the car of X." + (car (cdr (cdr (car X))))) +(put 'caddar 'byte-compile 'byte-compile-ca*d*r) + +(defun cdadar (X) + "Return the cdr of the car of the cdr of the car of X." + (cdr (car (cdr (car X))))) +(put 'cdadar 'byte-compile 'byte-compile-ca*d*r) + +(defun cddaar (X) + "Return the cdr of the cdr of the car of the car of X." + (cdr (cdr (car (car X))))) +(put 'cddaar 'byte-compile 'byte-compile-ca*d*r) + +(defun cadddr (X) + "Return the car of the cdr of the cdr of the cdr of X." + (car (cdr (cdr (cdr X))))) +(put 'cadddr 'byte-compile 'byte-compile-ca*d*r) + +(defun cddadr (X) + "Return the cdr of the cdr of the car of the cdr of X." + (cdr (cdr (car (cdr X))))) +(put 'cddadr 'byte-compile 'byte-compile-ca*d*r) + +(defun cdaddr (X) + "Return the cdr of the car of the cdr of the cdr of X." + (cdr (car (cdr (cdr X))))) +(put 'cdaddr 'byte-compile 'byte-compile-ca*d*r) + +(defun cdddar (X) + "Return the cdr of the cdr of the cdr of the car of X." + (cdr (cdr (cdr (car X))))) +(put 'cdddar 'byte-compile 'byte-compile-ca*d*r) + +(defun cddddr (X) + "Return the cdr of the cdr of the cdr of the cdr of X." + (cdr (cdr (cdr (cdr X))))) +(put 'cddddr 'byte-compile 'byte-compile-ca*d*r) + +;;; some inverses of the accessors are needed for setf purposes + +(defun setnth (n list newval) + "Set (nth N LIST) to NEWVAL. Returns NEWVAL." + (rplaca (nthcdr n list) newval)) + +(defun setnthcdr (n list newval) + "(setnthcdr N LIST NEWVAL) => NEWVAL +As a side effect, sets the Nth cdr of LIST to NEWVAL." + (cond ((< n 0) + (error "N must be 0 or greater, not %d" n)) + ((= n 0) + (rplaca list (car newval)) + (rplacd list (cdr newval)) + newval) + (t + (rplacd (nthcdr (- n 1) list) newval)))) + +;;; A-lists machinery + +(defun acons (key item alist) + "Return a new alist with KEY paired with ITEM; otherwise like ALIST. +Does not copy ALIST." + (cons (cons key item) alist)) + +(defun pairlis (keys data &optional alist) + "Return a new alist with each elt of KEYS paired with an elt of DATA; +optional 3rd arg ALIST is nconc'd at the end. KEYS and DATA must +have the same length." + (unless (= (length keys) (length data)) + (error "keys and data should be the same length")) + (do* ;;collect keys and data in front of alist + ((kptr keys (cdr kptr)) ;traverses the keys + (dptr data (cdr dptr)) ;traverses the data + (key (car kptr) (car kptr)) ;current key + (item (car dptr) (car dptr)) ;current data item + (result alist)) + ((endp kptr) result) + (setq result (acons key item result)))) + + +;;;; SEQUENCES +;;;; Emacs Lisp provides many of the 'sequences' functionality of +;;;; Common Lisp. This file provides a few things that were left out. +;;;; + + +(defkeyword :test "Used to designate positive (selection) tests.") +(defkeyword :test-not "Used to designate negative (rejection) tests.") +(defkeyword :key "Used to designate component extractions.") +(defkeyword :predicate "Used to define matching of sequence components.") +(defkeyword :start "Inclusive low index in sequence") +(defkeyword :end "Exclusive high index in sequence") +(defkeyword :start1 "Inclusive low index in first of two sequences.") +(defkeyword :start2 "Inclusive low index in second of two sequences.") +(defkeyword :end1 "Exclusive high index in first of two sequences.") +(defkeyword :end2 "Exclusive high index in second of two sequences.") +(defkeyword :count "Number of elements to affect.") +(defkeyword :from-end "T when counting backwards.") + +(defun some (pred seq &rest moreseqs) + "Test PREDICATE on each element of SEQUENCE; is it ever non-nil? +Extra args are additional sequences; PREDICATE gets one arg from each +sequence and we advance down all the sequences together in lock-step. +A sequence means either a list or a vector." + (let ((args (reassemble-argslists (list* seq moreseqs)))) + (do* ((ready nil) ;flag: return when t + (result nil) ;resulting value + (applyval nil) ;result of applying pred once + (remaining args + (cdr remaining)) ;remaining argument sets + (current (car remaining) ;current argument set + (car remaining))) + ((or ready (endp remaining)) result) + (setq applyval (apply pred current)) + (when applyval + (setq ready t) + (setq result applyval))))) + +(defun every (pred seq &rest moreseqs) + "Test PREDICATE on each element of SEQUENCE; is it always non-nil? +Extra args are additional sequences; PREDICATE gets one arg from each +sequence and we advance down all the sequences together in lock-step. +A sequence means either a list or a vector." + (let ((args (reassemble-argslists (list* seq moreseqs)))) + (do* ((ready nil) ;flag: return when t + (result t) ;resulting value + (applyval nil) ;result of applying pred once + (remaining args + (cdr remaining)) ;remaining argument sets + (current (car remaining) ;current argument set + (car remaining))) + ((or ready (endp remaining)) result) + (setq applyval (apply pred current)) + (unless applyval + (setq ready t) + (setq result nil))))) + +(defun notany (pred seq &rest moreseqs) + "Test PREDICATE on each element of SEQUENCE; is it always nil? +Extra args are additional sequences; PREDICATE gets one arg from each +sequence and we advance down all the sequences together in lock-step. +A sequence means either a list or a vector." + (let ((args (reassemble-argslists (list* seq moreseqs)))) + (do* ((ready nil) ;flag: return when t + (result t) ;resulting value + (applyval nil) ;result of applying pred once + (remaining args + (cdr remaining)) ;remaining argument sets + (current (car remaining) ;current argument set + (car remaining))) + ((or ready (endp remaining)) result) + (setq applyval (apply pred current)) + (when applyval + (setq ready t) + (setq result nil))))) + +(defun notevery (pred seq &rest moreseqs) + "Test PREDICATE on each element of SEQUENCE; is it sometimes nil? +Extra args are additional sequences; PREDICATE gets one arg from each +sequence and we advance down all the sequences together in lock-step. +A sequence means either a list or a vector." + (let ((args (reassemble-argslists (list* seq moreseqs)))) + (do* ((ready nil) ;flag: return when t + (result nil) ;resulting value + (applyval nil) ;result of applying pred once + (remaining args + (cdr remaining)) ;remaining argument sets + (current (car remaining) ;current argument set + (car remaining))) + ((or ready (endp remaining)) result) + (setq applyval (apply pred current)) + (unless applyval + (setq ready t) + (setq result t))))) + +;;; More sequence functions that don't need keyword arguments + +(defun concatenate (type &rest sequences) + "(concatenate TYPE &rest SEQUENCES) => a sequence +The sequence returned is of type TYPE (must be 'list, 'string, or 'vector) and +contains the concatenation of the elements of all the arguments, in the order +given." + (let ((sequences (append sequences '(())))) + (case type + (list + (apply (function append) sequences)) + (string + (apply (function concat) sequences)) + (vector + (apply (function vector) (apply (function append) sequences))) + (t + (error "type for concatenate `%s' not 'list, 'string or 'vector" + (prin1-to-string type)))))) + +(defun map (type function &rest sequences) + "(map TYPE FUNCTION &rest SEQUENCES) => a sequence +The FUNCTION is called on each set of elements from the SEQUENCES \(stopping +when the shortest sequence is terminated\) and the results are possibly +returned in a sequence of type TYPE \(one of 'list, 'vector, 'string, or nil\) +giving NIL for TYPE gets rid of the values." + (if (not (memq type (list 'list 'string 'vector nil))) + (error "type for map `%s' not 'list, 'string, 'vector or nil" + (prin1-to-string type))) + (let ((argslists (reassemble-argslists sequences)) + results) + (if (null type) + (while argslists ;don't bother accumulating + (apply function (car argslists)) + (setq argslists (cdr argslists))) + (setq results (mapcar (function (lambda (args) (apply function args))) + argslists)) + (case type + (list + results) + (string + (funcall (function concat) results)) + (vector + (apply (function vector) results)))))) + +;;; an inverse of elt is needed for setf purposes + +(defun setelt (seq n newval) + "In SEQUENCE, set the Nth element to NEWVAL. Returns NEWVAL. +A sequence means either a list or a vector." + (let ((l (length seq))) + (if (or (< n 0) (>= n l)) + (error "N(%d) should be between 0 and %d" n l) + ;; only two cases need be considered valid, as strings are arrays + (cond ((listp seq) + (setnth n seq newval)) + ((arrayp seq) + (aset seq n newval)) + (t + (error "SEQ should be a sequence, not `%s'" + (prin1-to-string seq))))))) + +;;; Testing with keyword arguments. +;;; +;;; Many of the sequence functions use keywords to denote some stylized +;;; form of selecting entries in a sequence. The involved arguments +;;; are collected with a &rest marker (as Emacs Lisp doesn't have a &key +;;; marker), then they are passed to build-klist, who +;;; constructs an association list. That association list is used to +;;; test for satisfaction and matching. + +;;; DON'T USE MEMBER, NOR ANY FUNCTION THAT COULD TAKE KEYWORDS HERE!!! + +(defun build-klist (argslist acceptable &optional allow-other-keys) + "Decode a keyword argument list ARGSLIST for keywords in ACCEPTABLE. +ARGSLIST is a list, presumably the &rest argument of a call, whose +even numbered elements must be keywords. +ACCEPTABLE is a list of keywords, the only ones that are truly acceptable. +The result is an alist containing the arguments named by the keywords +in ACCEPTABLE, or an error is signalled, if something failed. +If the third argument (an optional) is non-nil, other keys are acceptable." + ;; check legality of the arguments, then destructure them + (unless (and (listp argslist) + (evenp (length argslist))) + (error "build-klist: odd number of keyword-args")) + (unless (and (listp acceptable) + (every 'keywordp acceptable)) + (error "build-klist: second arg should be a list of keywords")) + (multiple-value-bind + (keywords forms) + (unzip-list argslist) + (unless (every 'keywordp keywords) + (error "build-klist: expected keywords, found `%s'" + (prin1-to-string keywords))) + (unless (or allow-other-keys + (every (function (lambda (keyword) + (memq keyword acceptable))) + keywords)) + (error "bad keyword[s]: %s not in %s" + (prin1-to-string (mapcan (function (lambda (keyword) + (if (memq keyword acceptable) + nil + (list keyword)))) + keywords)) + (prin1-to-string acceptable))) + (do* ;;pick up the pieces + ((auxlist ;auxiliary a-list, may + (pairlis keywords forms)) ;contain repetitions and junk + (ptr acceptable (cdr ptr)) ;pointer in acceptable + (this (car ptr) (car ptr)) ;current acceptable keyword + (auxval nil) ;used to move values around + (alist '())) ;used to build the result + ((endp ptr) alist) + ;; if THIS appears in auxlist, use its value + (when (setq auxval (assq this auxlist)) + (setq alist (cons auxval alist)))))) + + +(defun extract-from-klist (klist key &optional default) + "(extract-from-klist KLIST KEY [DEFAULT]) => value of KEY or DEFAULT +Extract value associated with KEY in KLIST (return DEFAULT if nil)." + (let ((retrieved (cdr (assq key klist)))) + (or retrieved default))) + +(defun keyword-argument-supplied-p (klist key) + "(keyword-argument-supplied-p KLIST KEY) => nil or something +NIL if KEY (a keyword) does not appear in the KLIST." + (assq key klist)) + +(defun add-to-klist (key item klist) + "(ADD-TO-KLIST KEY ITEM KLIST) => new KLIST +Add association (KEY . ITEM) to KLIST." + (setq klist (acons key item klist))) + +(defun elt-satisfies-test-p (item elt klist) + "(elt-satisfies-test-p ITEM ELT KLIST) => t or nil +KLIST encodes a keyword-arguments test, as in CH. 14 of CLtL. +True if the given ITEM and ELT satisfy the test." + (let ((test (extract-from-klist klist :test)) + (test-not (extract-from-klist klist :test-not)) + (keyfn (extract-from-klist klist :key 'identity))) + (cond (test + (funcall test item (funcall keyfn elt))) + (test-not + (not (funcall test-not item (funcall keyfn elt)))) + (t ;should never happen + (error "neither :test nor :test-not in `%s'" + (prin1-to-string klist)))))) + +(defun elt-satisfies-if-p (item klist) + "(elt-satisfies-if-p ITEM KLIST) => t or nil +True if an -if style function was called and ITEM satisfies the +predicate under :predicate in KLIST." + (let ((predicate (extract-from-klist klist :predicate)) + (keyfn (extract-from-klist klist :key 'identity))) + (funcall predicate item (funcall keyfn elt)))) + +(defun elt-satisfies-if-not-p (item klist) + "(elt-satisfies-if-not-p ITEM KLIST) => t or nil +KLIST encodes a keyword-arguments test, as in CH. 14 of CLtL. +True if an -if-not style function was called and ITEM does not satisfy +the predicate under :predicate in KLIST." + (let ((predicate (extract-from-klist klist :predicate)) + (keyfn (extract-from-klist klist :key 'identity))) + (not (funcall predicate item (funcall keyfn elt))))) + +(defun elts-match-under-klist-p (e1 e2 klist) + "(elts-match-under-klist-p E1 E2 KLIST) => t or nil +KLIST encodes a keyword-arguments test, as in CH. 14 of CLtL. +True if elements E1 and E2 match under the tests encoded in KLIST." + (let ((test (extract-from-klist klist :test)) + (test-not (extract-from-klist klist :test-not)) + (keyfn (extract-from-klist klist :key 'identity))) + (if (and test test-not) + (error "both :test and :test-not in `%s'" + (prin1-to-string klist))) + (cond (test + (funcall test (funcall keyfn e1) (funcall keyfn e2))) + (test-not + (not (funcall test-not (funcall keyfn e1) (funcall keyfn e2)))) + (t ;should never happen + (error "neither :test nor :test-not in `%s'" + (prin1-to-string klist)))))) + +;;; This macro simplifies using keyword args. It is less clumsy than using +;;; the primitives build-klist, etc... For instance, member could be written +;;; this way: + +;;; (defun member (item list &rest kargs) +;;; (with-keyword-args kargs (test test-not (key 'identity)) +;;; ...)) + +;;; Suggested by Robert Potter (potter@cs.rochester.edu, 15 Nov 1989) + +(defmacro with-keyword-args (keyargslist vardefs &rest body) + "(WITH-KEYWORD-ARGS KEYARGSLIST VARDEFS . BODY) +KEYARGSLIST can be either a symbol or a list of one or two symbols. +In the second case, the second symbol is either T or NIL, indicating whether +keywords other than the mentioned ones are tolerable. + +VARDEFS is a list. Each entry is either a VAR (symbol) or matches +\(VAR [DEFAULT [KEYWORD]]). Just giving VAR is the same as giving +\(VAR nil :VAR). + +The BODY is executed in an environment where each VAR (a symbol) is bound to +the value present in the KEYARGSLIST provided, or to the DEFAULT. The value +is searched by using the keyword form of VAR (i.e., :VAR) or the optional +keyword if provided. + +Notice that this macro doesn't distinguish between a default value given +explicitly by the user and one provided by default. See also the more +primitive functions build-klist, add-to-klist, extract-from-klist, +keyword-argument-supplied-p, elt-satisfies-test-p, elt-satisfies-if-p, +elt-satisfies-if-not-p, elts-match-under-klist-p. They provide more complete, +if clumsier, control over this feature." + (let (allow-other-keys) + (if (listp keyargslist) + (if (> (length keyargslist) 2) + (error + "`%s' should be SYMBOL, (SYMBOL), or (SYMBOL t-OR-nil)" + (prin1-to-string keyargslist)) + (setq allow-other-keys (cadr keyargslist) + keyargslist (car keyargslist)) + (if (not (and + (symbolp keyargslist) + (memq allow-other-keys '(t nil)))) + (error + "first subform should be SYMBOL, (SYMBOL), or (SYMBOL t-OR-nil)" + ))) + (if (symbolp keyargslist) + (setq allow-other-keys nil) + (error + "first subform should be SYMBOL, (SYMBOL), or (SYMBOL t-OR-nil)"))) + (let (vars defaults keywords forms + (klistname (gensym "KLIST_"))) + (mapcar (function (lambda (entry) + (if (symbolp entry) ;defaulty case + (setq entry (list entry nil (keyword-of entry)))) + (let* ((l (length entry)) + (v (car entry)) + (d (cadr entry)) + (k (caddr entry))) + (if (or (< l 1) (> l 3)) + (error + "`%s' must match (VAR [DEFAULT [KEYWORD]])" + (prin1-to-string entry))) + (if (or (null v) (not (symbolp v))) + (error + "bad variable `%s': must be non-null symbol" + (prin1-to-string v))) + (setq vars (cons v vars)) + (setq defaults (cons d defaults)) + (if (< l 3) + (setq k (keyword-of v))) + (if (and (= l 3) + (or (null k) + (not (keywordp k)))) + (error + "bad keyword `%s'" (prin1-to-string k))) + (setq keywords (cons k keywords)) + (setq forms (cons (list v (list 'extract-from-klist + klistname + k + d)) + forms))))) + vardefs) + (append + (list 'let* (nconc (list (list klistname + (list 'build-klist keyargslist + (list 'quote keywords) + allow-other-keys))) + (nreverse forms))) + body)))) +(put 'with-keyword-args 'lisp-indent-function 1) + + +;;; REDUCE +;;; It is here mostly as an example of how to use KLISTs. +;;; +;;; First of all, you need to declare the keywords (done elsewhere in this +;;; file): +;;; (defkeyword :from-end "syntax of sequence functions") +;;; (defkeyword :start "syntax of sequence functions") +;;; etc... +;;; +;;; Then, you capture all the possible keyword arguments with a &rest +;;; argument. You can pass that list downward again, of course, but +;;; internally you need to parse it into a KLIST (an alist, really). One uses +;;; (build-klist REST-ARGS ACCEPTABLE-KEYWORDS [ALLOW-OTHER]). You can then +;;; test for presence by using (keyword-argument-supplied-p KLIST KEY) and +;;; extract a value with (extract-from-klist KLIST KEY [DEFAULT]). + +(defun reduce (function sequence &rest kargs) + "Apply FUNCTION (a function of two arguments) to succesive pairs of elements +from SEQUENCE. Some keyword arguments are valid after FUNCTION and SEQUENCE: +:from-end If non-nil, process the values backwards +:initial-value If given, prefix it to the SEQUENCE. Suffix, if :from-end +:start Restrict reduction to the subsequence from this index +:end Restrict reduction to the subsequence BEFORE this index. +If the sequence is empty and no :initial-value is given, the FUNCTION is +called on zero (not two) arguments. Otherwise, if there is exactly one +element in the combination of SEQUENCE and the initial value, that element is +returned." + (let* ((klist (build-klist kargs '(:from-end :start :end :initial-value))) + (length (length sequence)) + (from-end (extract-from-klist klist :from-end)) + (initial-value-given (keyword-argument-supplied-p + klist :initial-value)) + (start (extract-from-klist kargs :start 0)) + (end (extract-from-klist kargs :end length))) + (setq sequence (cl$subseq-as-list sequence start end)) + (if from-end + (setq sequence (reverse sequence))) + (if initial-value-given + (setq sequence (cons (extract-from-klist klist :initial-value) + sequence))) + (if (null sequence) + (funcall function) ;only use of 0 arguments + (let* ((result (car sequence)) + (sequence (cdr sequence))) + (while sequence + (setq result (if from-end + (funcall function (car sequence) result) + (funcall function result (car sequence))) + sequence (cdr sequence))) + result)))) + +(defun cl$subseq-as-list (sequence start end) + "(cl$subseq-as-list SEQUENCE START END) => a list" + (let ((list (append sequence nil)) + (length (length sequence)) + result) + (if (< start 0) + (error "start should be >= 0, not %d" start)) + (if (> end length) + (error "end should be <= %d, not %d" length end)) + (if (and (zerop start) (= end length)) + list + (let ((i start) + (vector (apply 'vector list))) + (while (/= i end) + (setq result (cons (elt vector i) result)) + (setq i (+ i 1))) + (nreverse result))))) + +;;;; end of cl-sequences.el + +;;;; Some functions with keyword arguments +;;;; +;;;; Both list and sequence functions are considered here together. This +;;;; doesn't fit any more with the original split of functions in files. + +(defun member (item list &rest kargs) + "Look for ITEM in LIST; return first tail of LIST the car of whose first +cons cell tests the same as ITEM. Admits arguments :key, :test, and :test-not." + (if (null kargs) ;treat this fast for efficiency + (memq item list) + (let* ((klist (build-klist kargs '(:test :test-not :key))) + (test (extract-from-klist klist :test)) + (testnot (extract-from-klist klist :test-not)) + (key (extract-from-klist klist :key 'identity))) + ;; another workaround allegledly for speed + (if (and (or (eq test 'eq) (eq test 'eql) + (eq test (symbol-function 'eq)) + (eq test (symbol-function 'eql))) + (null testnot) + (or (eq key 'identity) ;either by default or so given + (eq key (function identity)) ;could this happen? + (eq key (symbol-function 'identity)) ;sheer paranoia + )) + (memq item list) + (if (and test testnot) + (error ":test and :test-not both specified for member")) + (if (not (or test testnot)) + (setq test 'eql)) + ;; final hack: remove the indirection through the function names + (if testnot + (if (symbolp testnot) + (setq testnot (symbol-function testnot))) + (if (symbolp test) + (setq test (symbol-function test)))) + (if (symbolp key) + (setq key (symbol-function key))) + ;; ok, go for it + (let ((ptr list) + (done nil) + (result '())) + (if testnot + (while (not (or done (endp ptr))) + (cond ((not (funcall testnot item (funcall key (car ptr)))) + (setq done t) + (setq result ptr))) + (setq ptr (cdr ptr))) + (while (not (or done (endp ptr))) + (cond ((funcall test item (funcall key (car ptr))) + (setq done t) + (setq result ptr))) + (setq ptr (cdr ptr)))) + result))))) + +;;;; MULTIPLE VALUES +;;;; This package approximates the behavior of the multiple-values +;;;; forms of Common Lisp. +;;;; +;;;; Cesar Quiroz @ UofR DofCSc - Dec. 1986 +;;;; (quiroz@cs.rochester.edu) + +;;; Lisp indentation information +(put 'multiple-value-bind 'lisp-indent-function 2) +(put 'multiple-value-setq 'lisp-indent-function 2) +(put 'multiple-value-list 'lisp-indent-function nil) +(put 'multiple-value-call 'lisp-indent-function 1) +(put 'multiple-value-prog1 'lisp-indent-function 1) + +;;; Global state of the package is kept here +(defvar *mvalues-values* nil + "Most recently returned multiple-values") +(defvar *mvalues-count* nil + "Count of multiple-values returned, or nil if the mechanism was not used") + +;;; values is the standard multiple-value-return form. Must be the +;;; last thing evaluated inside a function. If the caller is not +;;; expecting multiple values, only the first one is passed. (values) +;;; is the same as no-values returned (unaware callers see nil). The +;;; alternative (values-list ) is just a convenient shorthand +;;; and complements multiple-value-list. + +(defun values (&rest val-forms) + "Produce multiple values (zero or more). Each arg is one value. +See also `multiple-value-bind', which is one way to examine the +multiple values produced by a form. If the containing form or caller +does not check specially to see multiple values, it will see only +the first value." + (setq *mvalues-values* val-forms) + (setq *mvalues-count* (length *mvalues-values*)) + (car *mvalues-values*)) + +(defun values-list (&optional val-forms) + "Produce multiple values (zero or mode). Each element of LIST is one value. +This is equivalent to (apply 'values LIST)." + (cond ((nlistp val-forms) + (error "Argument to values-list must be a list, not `%s'" + (prin1-to-string val-forms)))) + (setq *mvalues-values* val-forms) + (setq *mvalues-count* (length *mvalues-values*)) + (car *mvalues-values*)) + +;;; Callers that want to see the multiple values use these macros. + +(defmacro multiple-value-list (form) + "Execute FORM and return a list of all the (multiple) values FORM produces. +See `values' and `multiple-value-bind'." + (list 'progn + (list 'setq '*mvalues-count* nil) + (list 'let (list (list 'it '(gensym))) + (list 'set 'it form) + (list 'if '*mvalues-count* + (list 'copy-sequence '*mvalues-values*) + (list 'progn + (list 'setq '*mvalues-count* 1) + (list 'setq '*mvalues-values* + (list 'list (list 'symbol-value 'it))) + (list 'copy-sequence '*mvalues-values*)))))) + +(defmacro multiple-value-call (function &rest args) + "Call FUNCTION on all the values produced by the remaining arguments. +(multiple-value-call '+ (values 1 2) (values 3 4)) is 10." + (let* ((result (gentemp)) + (arg (gentemp))) + (list 'apply (list 'function (eval function)) + (list 'let* (list (list result '())) + (list 'dolist (list arg (list 'quote args) result) + (list 'setq result + (list 'append + result + (list 'multiple-value-list + (list 'eval arg))))))))) + +(defmacro multiple-value-bind (vars form &rest body) + "Bind VARS to the (multiple) values produced by FORM, then do BODY. +VARS is a list of variables; each is bound to one of FORM's values. +If FORM doesn't make enough values, the extra variables are bound to nil. +(Ordinary forms produce only one value; to produce more, use `values'.) +Extra values are ignored. +BODY (zero or more forms) is executed with the variables bound, +then the bindings are unwound." + (let* ((vals (gentemp)) ;name for intermediate values + (clauses (mv-bind-clausify ;convert into clauses usable + vars vals))) ; in a let form + (list* 'let* + (cons (list vals (list 'multiple-value-list form)) + clauses) + body))) + +(defmacro multiple-value-setq (vars form) + "Set VARS to the (multiple) values produced by FORM. +VARS is a list of variables; each is set to one of FORM's values. +If FORM doesn't make enough values, the extra variables are set to nil. +(Ordinary forms produce only one value; to produce more, use `values'.) +Extra values are ignored." + (let* ((vals (gentemp)) ;name for intermediate values + (clauses (mv-bind-clausify ;convert into clauses usable + vars vals))) ; in a setq (after append). + (list 'let* + (list (list vals (list 'multiple-value-list form))) + (cons 'setq (apply (function append) clauses))))) + +(defmacro multiple-value-prog1 (form &rest body) + "Evaluate FORM, then BODY, then produce the same values FORM produced. +Thus, (multiple-value-prog1 (values 1 2) (foobar)) produces values 1 and 2. +This is like `prog1' except that `prog1' would produce only one value, +which would be the first of FORM's values." + (let* ((heldvalues (gentemp))) + (cons 'let* + (cons (list (list heldvalues (list 'multiple-value-list form))) + (append body (list (list 'values-list heldvalues))))))) + +;;; utility functions +;;; +;;; mv-bind-clausify makes the pairs needed to have the variables in +;;; the variable list correspond with the values returned by the form. +;;; vals is a fresh symbol that intervenes in all the bindings. + +(defun mv-bind-clausify (vars vals) + "MV-BIND-CLAUSIFY VARS VALS => Auxiliary list +Forms a list of pairs `(,(nth i vars) (nth i vals)) for i from 0 to +the length of VARS (a list of symbols). VALS is just a fresh symbol." + (if (or (nlistp vars) + (notevery 'symbolp vars)) + (error "expected a list of symbols, not `%s'" + (prin1-to-string vars))) + (let* ((nvars (length vars)) + (clauses '())) + (dotimes (n nvars clauses) + (setq clauses (cons (list (nth n vars) + (list 'nth n vals)) clauses))))) + +;;;; end of cl-multiple-values.el + +;;;; ARITH +;;;; This file provides integer arithmetic extensions. Although +;;;; Emacs Lisp doesn't really support anything but integers, that +;;;; has still to be made to look more or less standard. +;;;; +;;;; +;;;; Cesar Quiroz @ UofR DofCSc - Dec. 1986 +;;;; (quiroz@cs.rochester.edu) + + +(defun plusp (number) + "True if NUMBER is strictly greater than zero." + (> number 0)) + +(defun minusp (number) + "True if NUMBER is strictly less than zero." + (< number 0)) + +(defun oddp (number) + "True if INTEGER is not divisible by 2." + (/= (% number 2) 0)) + +(defun evenp (number) + "True if INTEGER is divisible by 2." + (= (% number 2) 0)) + +(defun abs (number) + "Return the absolute value of NUMBER." + (if (< number 0) + (- number) + number)) + +(defun signum (number) + "Return -1, 0 or 1 according to the sign of NUMBER." + (cond ((< number 0) + -1) + ((> number 0) + 1) + (t ;exactly zero + 0))) + +(defun gcd (&rest integers) + "Return the greatest common divisor of all the arguments. +The arguments must be integers. With no arguments, value is zero." + (let ((howmany (length integers))) + (cond ((= howmany 0) + 0) + ((= howmany 1) + (abs (car integers))) + ((> howmany 2) + (apply (function gcd) + (cons (gcd (nth 0 integers) (nth 1 integers)) + (nthcdr 2 integers)))) + (t ;howmany=2 + ;; essentially the euclidean algorithm + (when (zerop (* (nth 0 integers) (nth 1 integers))) + (error "a zero argument is invalid for `gcd'")) + (do* ((absa (abs (nth 0 integers))) ; better to operate only + (absb (abs (nth 1 integers))) ;on positives. + (dd (max absa absb)) ; setup correct order for the + (ds (min absa absb)) ;succesive divisions. + ;; intermediate results + (q 0) + (r 0) + ;; final results + (done nil) ; flag: end of iterations + (result 0)) ; final value + (done result) + (setq q (/ dd ds)) + (setq r (% dd ds)) + (cond ((zerop r) (setq done t) (setq result ds)) + (t (setq dd ds) (setq ds r)))))))) + +(defun lcm (integer &rest more) + "Return the least common multiple of all the arguments. +The arguments must be integers and there must be at least one of them." + (let ((howmany (length more)) + (a integer) + (b (nth 0 more)) + prod ; intermediate product + (yetmore (nthcdr 1 more))) + (cond ((zerop howmany) + (abs a)) + ((> howmany 1) ; recursive case + (apply (function lcm) + (cons (lcm a b) yetmore))) + (t ; base case, just 2 args + (setq prod (* a b)) + (cond + ((zerop prod) + 0) + (t + (/ (abs prod) (gcd a b)))))))) + +(defun isqrt (number) + "Return the integer square root of NUMBER. +NUMBER must not be negative. Result is largest integer less than or +equal to the real square root of the argument." + ;; The method used here is essentially the Newtonian iteration + ;; x[n+1] <- (x[n] + Number/x[n]) / 2 + ;; suitably adapted to integer arithmetic. + ;; Thanks to Philippe Schnoebelen for suggesting the + ;; termination condition. + (cond ((minusp number) + (error "argument to `isqrt' (%d) must not be negative" + number)) + ((zerop number) + 0) + (t ;so (>= number 0) + (do* ((approx 1) ;any positive integer will do + (new 0) ;init value irrelevant + (done nil)) + (done (if (> (* approx approx) number) + (- approx 1) + approx)) + (setq new (/ (+ approx (/ number approx)) 2) + done (or (= new approx) (= new (+ approx 1))) + approx new))))) + +(defun floor (number &optional divisor) + "Divide DIVIDEND by DIVISOR, rounding toward minus infinity. +DIVISOR defaults to 1. The remainder is produced as a second value." + (cond + ((and (null divisor) ; trivial case + (numberp number)) + (values number 0)) + (t ; do the division + (multiple-value-bind + (q r s) + (safe-idiv number divisor) + (cond ((zerop s) + (values 0 0)) + ((plusp s) + (values q r)) + (t ;opposite-signs case + (if (zerop r) + (values (- q) 0) + (let ((q (- (+ q 1)))) + (values q (- number (* q divisor))))))))))) + +(defun ceiling (number &optional divisor) + "Divide DIVIDEND by DIVISOR, rounding toward plus infinity. +DIVISOR defaults to 1. The remainder is produced as a second value." + (cond + ((and (null divisor) ; trivial case + (numberp number)) + (values number 0)) + (t ; do the division + (multiple-value-bind + (q r s) + (safe-idiv number divisor) + (cond ((zerop s) + (values 0 0)) + ((plusp s) + (values (+ q 1) (- r divisor))) + (t + (values (- q) (+ number (* q divisor))))))))) + +(defun truncate (number &optional divisor) + "Divide DIVIDEND by DIVISOR, rounding toward zero. +DIVISOR defaults to 1. The remainder is produced as a second value." + (cond + ((and (null divisor) ; trivial case + (numberp number)) + (values number 0)) + (t ; do the division + (multiple-value-bind + (q r s) + (safe-idiv number divisor) + (cond ((zerop s) + (values 0 0)) + ((plusp s) ;same as floor + (values q r)) + (t ;same as ceiling + (values (- q) (+ number (* q divisor))))))))) + +(defun round (number &optional divisor) + "Divide DIVIDEND by DIVISOR, rounding to nearest integer. +DIVISOR defaults to 1. The remainder is produced as a second value." + (cond ((and (null divisor) ; trivial case + (numberp number)) + (values number 0)) + (t ; do the division + (multiple-value-bind + (q r s) + (safe-idiv number divisor) + (setq r (abs r)) + ;; adjust magnitudes first, and then signs + (let ((other-r (- (abs divisor) r))) + (cond ((> r other-r) + (setq q (+ q 1))) + ((and (= r other-r) + (oddp q)) + ;; round to even is mandatory + (setq q (+ q 1)))) + (setq q (* s q)) + (setq r (- number (* q divisor))) + (values q r)))))) + +(defun mod (number divisor) + "Return remainder of X by Y (rounding quotient toward minus infinity). +That is, the remainder goes with the quotient produced by `floor'." + (multiple-value-bind (q r) (floor number divisor) + r)) + +(defun rem (number divisor) + "Return remainder of X by Y (rounding quotient toward zero). +That is, the remainder goes with the quotient produced by `truncate'." + (multiple-value-bind (q r) (truncate number divisor) + r)) + +;;; internal utilities +;;; +;;; safe-idiv performs an integer division with positive numbers only. +;;; It is known that some machines/compilers implement weird remainder +;;; computations when working with negatives, so the idea here is to +;;; make sure we know what is coming back to the caller in all cases. + +;;; Signum computation fixed by mad@math.keio.JUNET (MAEDA Atusi) + +(defun safe-idiv (a b) + "SAFE-IDIV A B => Q R S +Q=|A|/|B|, R is the rest, S is the sign of A/B." + (unless (and (numberp a) (numberp b)) + (error "arguments to `safe-idiv' must be numbers")) + (when (zerop b) + (error "cannot divide %d by zero" a)) + (let* ((absa (abs a)) + (absb (abs b)) + (q (/ absa absb)) + (s (* (signum a) (signum b))) + (r (- a (* (* s q) b)))) + (values q r s))) + +;;;; end of cl-arith.el + +;;;; SETF +;;;; This file provides the setf macro and friends. The purpose has +;;;; been modest, only the simplest defsetf forms are accepted. +;;;; Use it and enjoy. +;;;; +;;;; Cesar Quiroz @ UofR DofCSc - Dec. 1986 +;;;; (quiroz@cs.rochester.edu) + + +(defkeyword :setf-update-fn + "Property, its value is the function setf must invoke to update a +generalized variable whose access form is a function call of the +symbol that has this property.") + +(defkeyword :setf-update-doc + "Property of symbols that have a `defsetf' update function on them, +installed by the `defsetf' from its optional third argument.") + +(defmacro setf (&rest pairs) + "Generalized `setq' that can set things other than variable values. +A use of `setf' looks like (setf {PLACE VALUE}...). +The behavior of (setf PLACE VALUE) is to access the generalized variable +at PLACE and store VALUE there. It returns VALUE. If there is more +than one PLACE and VALUE, each PLACE is set from its VALUE before +the next PLACE is evaluated." + (let ((nforms (length pairs))) + ;; check the number of subforms + (cond ((/= (% nforms 2) 0) + (error "odd number of arguments to `setf'")) + ((= nforms 0) + nil) + ((> nforms 2) + ;; this is the recursive case + (cons 'progn + (do* ;collect the place-value pairs + ((args pairs (cddr args)) + (place (car args) (car args)) + (value (cadr args) (cadr args)) + (result '())) + ((endp args) (nreverse result)) + (setq result + (cons (list 'setf place value) + result))))) + (t ;i.e., nforms=2 + ;; this is the base case (SETF PLACE VALUE) + (let* ((place (car pairs)) + (value (cadr pairs)) + (head nil) + (updatefn nil)) + ;; dispatch on the type of the PLACE + (cond ((symbolp place) + (list 'setq place value)) + ((and (listp place) + (setq head (car place)) + (symbolp head) + (setq updatefn (get head :setf-update-fn))) + (if (or (and (consp updatefn) (eq (car updatefn) 'lambda)) + (and (symbolp updatefn) + (fboundp updatefn) + (let ((defn (symbol-function updatefn))) + (or (subrp defn) + (and (consp defn) + (eq (car defn) 'lambda)))))) + (cons updatefn (append (cdr place) (list value))) + (multiple-value-bind + (bindings newsyms) + (pair-with-newsyms (append (cdr place) (list value))) + ;; this let gets new symbols to ensure adequate + ;; order of evaluation of the subforms. + (list 'let + bindings + (cons updatefn newsyms))))) + (t + (error "no `setf' update-function for `%s'" + (prin1-to-string place))))))))) + +(defmacro defsetf (accessfn updatefn &optional docstring) + "Define how `setf' works on a certain kind of generalized variable. +A use of `defsetf' looks like (defsetf ACCESSFN UPDATEFN [DOCSTRING]). +ACCESSFN is a symbol. UPDATEFN is a function or macro which takes +one more argument than ACCESSFN does. DEFSETF defines the translation +of (SETF (ACCESFN . ARGS) NEWVAL) to be a form like (UPDATEFN ARGS... NEWVAL). +The function UPDATEFN must return its last arg, after performing the +updating called for." + ;; reject ill-formed requests. too bad one can't test for functionp + ;; or macrop. + (when (not (symbolp accessfn)) + (error "first argument of `defsetf' must be a symbol, not `%s'" + (prin1-to-string accessfn))) + ;; update properties + (list 'progn + (list 'put (list 'quote accessfn) + :setf-update-fn (list 'function updatefn)) + (list 'put (list 'quote accessfn) :setf-update-doc docstring) + ;; any better thing to return? + (list 'quote accessfn))) + +;;; This section provides the "default" setfs for Common-Emacs-Lisp +;;; The user will not normally add anything to this, although +;;; defstruct will introduce new ones as a matter of fact. +;;; +;;; Apply is a special case. The Common Lisp +;;; standard makes the case of apply be useful when the user writes +;;; something like (apply #'name ...), Emacs Lisp doesn't have the # +;;; stuff, but it has (function ...). Notice that V18 includes a new +;;; apply: this file is compatible with V18 and pre-V18 Emacses. + +;;; INCOMPATIBILITY: the SETF macro evaluates its arguments in the +;;; (correct) left to right sequence *before* checking for apply +;;; methods (which should really be an special case inside setf). Due +;;; to this, the lambda expression defsetf'd to apply will succeed in +;;; applying the right function even if the name was not quoted, but +;;; computed! That extension is not Common Lisp (nor is particularly +;;; useful, I think). + +(defsetf apply + (lambda (&rest args) + ;; dissasemble the calling form + ;; "(((quote fn) x1 x2 ... xn) val)" (function instead of quote, too) + (let* ((fnform (car args)) ;functional form + (applyargs (append ;arguments "to apply fnform" + (apply 'list* (butlast (cdr args))) + (last args))) + (newupdater nil)) ; its update-fn, if any + (if (and (symbolp fnform) + (setq newupdater (get fnform :setf-update-fn))) + (apply newupdater applyargs) + (error "can't `setf' to `%s'" + (prin1-to-string fnform))))) + "`apply' is a special case for `setf'") + + +(defsetf aref + aset + "`setf' inversion for `aref'") + +(defsetf nth + setnth + "`setf' inversion for `nth'") + +(defsetf nthcdr + setnthcdr + "`setf' inversion for `nthcdr'") + +(defsetf elt + setelt + "`setf' inversion for `elt'") + +(defsetf first + (lambda (list val) (setnth 0 list val)) + "`setf' inversion for `first'") + +(defsetf second + (lambda (list val) (setnth 1 list val)) + "`setf' inversion for `second'") + +(defsetf third + (lambda (list val) (setnth 2 list val)) + "`setf' inversion for `third'") + +(defsetf fourth + (lambda (list val) (setnth 3 list val)) + "`setf' inversion for `fourth'") + +(defsetf fifth + (lambda (list val) (setnth 4 list val)) + "`setf' inversion for `fifth'") + +(defsetf sixth + (lambda (list val) (setnth 5 list val)) + "`setf' inversion for `sixth'") + +(defsetf seventh + (lambda (list val) (setnth 6 list val)) + "`setf' inversion for `seventh'") + +(defsetf eighth + (lambda (list val) (setnth 7 list val)) + "`setf' inversion for `eighth'") + +(defsetf ninth + (lambda (list val) (setnth 8 list val)) + "`setf' inversion for `ninth'") + +(defsetf tenth + (lambda (list val) (setnth 9 list val)) + "`setf' inversion for `tenth'") + +(defsetf rest + (lambda (list val) (setcdr list val)) + "`setf' inversion for `rest'") + +(defsetf car setcar "Replace the car of a cons") + +(defsetf cdr setcdr "Replace the cdr of a cons") + +(defsetf caar + (lambda (list val) (setcar (nth 0 list) val)) + "`setf' inversion for `caar'") + +(defsetf cadr + (lambda (list val) (setcar (cdr list) val)) + "`setf' inversion for `cadr'") + +(defsetf cdar + (lambda (list val) (setcdr (car list) val)) + "`setf' inversion for `cdar'") + +(defsetf cddr + (lambda (list val) (setcdr (cdr list) val)) + "`setf' inversion for `cddr'") + +(defsetf caaar + (lambda (list val) (setcar (caar list) val)) + "`setf' inversion for `caaar'") + +(defsetf caadr + (lambda (list val) (setcar (cadr list) val)) + "`setf' inversion for `caadr'") + +(defsetf cadar + (lambda (list val) (setcar (cdar list) val)) + "`setf' inversion for `cadar'") + +(defsetf cdaar + (lambda (list val) (setcdr (caar list) val)) + "`setf' inversion for `cdaar'") + +(defsetf caddr + (lambda (list val) (setcar (cddr list) val)) + "`setf' inversion for `caddr'") + +(defsetf cdadr + (lambda (list val) (setcdr (cadr list) val)) + "`setf' inversion for `cdadr'") + +(defsetf cddar + (lambda (list val) (setcdr (cdar list) val)) + "`setf' inversion for `cddar'") + +(defsetf cdddr + (lambda (list val) (setcdr (cddr list) val)) + "`setf' inversion for `cdddr'") + +(defsetf caaaar + (lambda (list val) (setcar (caaar list) val)) + "`setf' inversion for `caaaar'") + +(defsetf caaadr + (lambda (list val) (setcar (caadr list) val)) + "`setf' inversion for `caaadr'") + +(defsetf caadar + (lambda (list val) (setcar (cadar list) val)) + "`setf' inversion for `caadar'") + +(defsetf cadaar + (lambda (list val) (setcar (cdaar list) val)) + "`setf' inversion for `cadaar'") + +(defsetf cdaaar + (lambda (list val) (setcdr (caar list) val)) + "`setf' inversion for `cdaaar'") + +(defsetf caaddr + (lambda (list val) (setcar (caddr list) val)) + "`setf' inversion for `caaddr'") + +(defsetf cadadr + (lambda (list val) (setcar (cdadr list) val)) + "`setf' inversion for `cadadr'") + +(defsetf cdaadr + (lambda (list val) (setcdr (caadr list) val)) + "`setf' inversion for `cdaadr'") + +(defsetf caddar + (lambda (list val) (setcar (cddar list) val)) + "`setf' inversion for `caddar'") + +(defsetf cdadar + (lambda (list val) (setcdr (cadar list) val)) + "`setf' inversion for `cdadar'") + +(defsetf cddaar + (lambda (list val) (setcdr (cdaar list) val)) + "`setf' inversion for `cddaar'") + +(defsetf cadddr + (lambda (list val) (setcar (cdddr list) val)) + "`setf' inversion for `cadddr'") + +(defsetf cddadr + (lambda (list val) (setcdr (cdadr list) val)) + "`setf' inversion for `cddadr'") + +(defsetf cdaddr + (lambda (list val) (setcdr (caddr list) val)) + "`setf' inversion for `cdaddr'") + +(defsetf cdddar + (lambda (list val) (setcdr (cddar list) val)) + "`setf' inversion for `cdddar'") + +(defsetf cddddr + (lambda (list val) (setcdr (cddr list) val)) + "`setf' inversion for `cddddr'") + +(defsetf get put "`setf' inversion for `get' is `put'") + +(defsetf symbol-function fset + "`setf' inversion for `symbol-function' is `fset'") + +(defsetf symbol-plist setplist + "`setf' inversion for `symbol-plist' is `setplist'") + +(defsetf symbol-value set + "`setf' inversion for `symbol-value' is `set'") + +(defsetf point goto-char + "To set (point) to N, use (goto-char N)") + +;; how about defsetfing other Emacs forms? + +;;; Modify macros +;;; +;;; It could be nice to implement define-modify-macro, but I don't +;;; think it really pays. + +(defmacro incf (ref &optional delta) + "(incf REF [DELTA]) -> increment the g.v. REF by DELTA (default 1)" + (if (null delta) + (setq delta 1)) + (list 'setf ref (list '+ ref delta))) + +(defmacro decf (ref &optional delta) + "(decf REF [DELTA]) -> decrement the g.v. REF by DELTA (default 1)" + (if (null delta) + (setq delta 1)) + (list 'setf ref (list '- ref delta))) + +(defmacro push (item ref) + "(push ITEM REF) -> cons ITEM at the head of the g.v. REF (a list)" + (list 'setf ref (list 'cons item ref))) + +(defmacro pushnew (item ref) + "(pushnew ITEM REF): adjoin ITEM at the head of the g.v. REF (a list)" + (list 'setf ref (list 'adjoin item ref))) + +(defmacro pop (ref) + "(pop REF) -> (prog1 (car REF) (setf REF (cdr REF)))" + (let ((listname (gensym))) + (list 'let (list (list listname ref)) + (list 'prog1 + (list 'car listname) + (list 'setf ref (list 'cdr listname)))))) + +;;; PSETF +;;; +;;; Psetf is the generalized variable equivalent of psetq. The right +;;; hand sides are evaluated and assigned (via setf) to the left hand +;;; sides. The evaluations are done in an environment where they +;;; appear to occur in parallel. + +(defmacro psetf (&rest body) + "(psetf {var value }...) => nil +Like setf, but all the values are computed before any assignment is made." + (let ((length (length body))) + (cond ((/= (% length 2) 0) + (error "psetf needs an even number of arguments, %d given" + length)) + ((null body) + '()) + (t + (list 'prog1 nil + (let ((setfs '()) + (bodyforms (reverse body))) + (while bodyforms + (let* ((value (car bodyforms)) + (place (cadr bodyforms))) + (setq bodyforms (cddr bodyforms)) + (if (null setfs) + (setq setfs (list 'setf place value)) + (setq setfs (list 'setf place + (list 'prog1 value + setfs)))))) + setfs)))))) + +;;; SHIFTF and ROTATEF +;;; + +(defmacro shiftf (&rest forms) + "(shiftf PLACE1 PLACE2... NEWVALUE) +Set PLACE1 to PLACE2, PLACE2 to PLACE3... +Each PLACE is set to the old value of the following PLACE, +and the last PLACE is set to the value NEWVALUE. +Returns the old value of PLACE1." + (unless (> (length forms) 1) + (error "`shiftf' needs more than one argument")) + (let ((places (butlast forms)) + (newvalue (car (last forms)))) + ;; the places are accessed to fresh symbols + (multiple-value-bind + (bindings newsyms) + (pair-with-newsyms places) + (list 'let bindings + (cons 'setf + (zip-lists places + (append (cdr newsyms) (list newvalue)))) + (car newsyms))))) + +(defmacro rotatef (&rest places) + "(rotatef PLACE...) sets each PLACE to the old value of the following PLACE. +The last PLACE is set to the old value of the first PLACE. +Thus, the values rotate through the PLACEs. Returns nil." + (if (null places) + nil + (multiple-value-bind + (bindings newsyms) + (pair-with-newsyms places) + (list + 'let bindings + (cons 'setf + (zip-lists places + (append (cdr newsyms) (list (car newsyms))))) + nil)))) + +;;;; STRUCTS +;;;; This file provides the structures mechanism. See the +;;;; documentation for Common-Lisp's defstruct. Mine doesn't +;;;; implement all the functionality of the standard, although some +;;;; more could be grafted if so desired. More details along with +;;;; the code. +;;;; +;;;; +;;;; Cesar Quiroz @ UofR DofCSc - Dec. 1986 +;;;; (quiroz@cs.rochester.edu) + + +(defkeyword :include "Syntax of `defstruct'") +(defkeyword :named "Syntax of `defstruct'") +(defkeyword :conc-name "Syntax of `defstruct'") +(defkeyword :copier "Syntax of `defstruct'") +(defkeyword :predicate "Syntax of `defstruct'") +(defkeyword :print-function "Syntax of `defstruct'") +(defkeyword :type "Syntax of `defstruct'") +(defkeyword :initial-offset "Syntax of `defstruct'") + +(defkeyword :structure-doc "Documentation string for a structure.") +(defkeyword :structure-slotsn "Number of slots in structure") +(defkeyword :structure-slots "List of the slot's names") +(defkeyword :structure-indices "List of (KEYWORD-NAME . INDEX)") +(defkeyword :structure-initforms "List of (KEYWORD-NAME . INITFORM)") +(defkeyword :structure-includes + "() or list of a symbol, that this struct includes") +(defkeyword :structure-included-in + "List of the structs that include this") + + +(defmacro defstruct (&rest args) + "(defstruct NAME [DOC-STRING] . SLOTS) define NAME as structure type. +NAME must be a symbol, the name of the new structure. It could also +be a list (NAME . OPTIONS). + +Each option is either a symbol, or a list of a keyword symbol taken from the +list \{:conc-name, :copier, :constructor, :predicate, :include, +:print-function, :type, :initial-offset\}. The meanings of these are as in +CLtL, except that no BOA-constructors are provided, and the options +\{:print-fuction, :type, :initial-offset\} are ignored quietly. All these +structs are named, in the sense that their names can be used for type +discrimination. + +The DOC-STRING is established as the `structure-doc' property of NAME. + +The SLOTS are one or more of the following: +SYMBOL -- meaning the SYMBOL is the name of a SLOT of NAME +list of SYMBOL and VALUE -- meaning that VALUE is the initial value of +the slot. +`defstruct' defines functions `make-NAME', `NAME-p', `copy-NAME' for the +structure, and functions with the same name as the slots to access +them. `setf' of the accessors sets their values." + (multiple-value-bind + (name options docstring slotsn slots initlist) + (parse$defstruct$args args) + ;; Names for the member functions come from the options. The + ;; slots* stuff collects info about the slots declared explicitly. + (multiple-value-bind + (conc-name constructor copier predicate + moreslotsn moreslots moreinits included) + (parse$defstruct$options name options slots) + ;; The moreslots* stuff refers to slots gained as a consequence + ;; of (:include clauses). -- Oct 89: Only one :include tolerated + (when (and (numberp moreslotsn) + (> moreslotsn 0)) + (setf slotsn (+ slotsn moreslotsn)) + (setf slots (append moreslots slots)) + (setf initlist (append moreinits initlist))) + (unless (> slotsn 0) + (error "%s needs at least one slot" + (prin1-to-string name))) + (let ((dups (duplicate-symbols-p slots))) + (when dups + (error "`%s' are duplicates" + (prin1-to-string dups)))) + (setq initlist (simplify$inits slots initlist)) + (let (properties functions keywords accessors alterators returned) + ;; compute properties of NAME + (setq properties + (append + (list + (list 'put (list 'quote name) :structure-doc + docstring) + (list 'put (list 'quote name) :structure-slotsn + slotsn) + (list 'put (list 'quote name) :structure-slots + (list 'quote slots)) + (list 'put (list 'quote name) :structure-initforms + (list 'quote initlist)) + (list 'put (list 'quote name) :structure-indices + (list 'quote (extract$indices initlist)))) + ;; If this definition :includes another defstruct, + ;; modify both property lists. + (cond (included + (list + (list 'put + (list 'quote name) + :structure-includes + (list 'quote included)) + (list 'pushnew + (list 'quote name) + (list 'get (list 'quote (car included)) + :structure-included-in)))) + (t + (list + (let ((old (gensym))) + (list 'let + (list (list old + (list 'car + (list 'get + (list 'quote name) + :structure-includes)))) + (list 'when old + (list 'put + old + :structure-included-in + (list 'delq + (list 'quote name) + ;; careful with destructive + ;;manipulation! + (list + 'append + (list + 'get + old + :structure-included-in) + '()) + ))))) + (list 'put + (list 'quote name) + :structure-includes + '())))) + ;; If this definition used to be :included in another, warn + ;; that things make break. On the other hand, the redefinition + ;; may be trivial, so don't call it an error. + (let ((old (gensym))) + (list + (list 'let + (list (list old (list 'get + (list 'quote name) + :structure-included-in))) + (list 'when old + (list 'message + "`%s' redefined. Should redefine `%s'?" + (list 'quote name) + (list 'prin1-to-string old)))))))) + + ;; Compute functions associated with NAME. This is not + ;; handling BOA constructors yet, but here would be the place. + (setq functions + (list + (list 'fset (list 'quote constructor) + (list 'function + (list 'lambda (list '&rest 'args) + (list 'make$structure$instance + (list 'quote name) + 'args)))) + (list 'fset (list 'quote copier) + (list 'function + (list 'lambda (list 'struct) + (list 'copy-sequence 'struct)))) + (let ((typetag (gensym))) + (list 'fset (list 'quote predicate) + (list + 'function + (list + 'lambda (list 'thing) + (list 'and + (list 'vectorp 'thing) + (list 'let + (list (list typetag + (list 'elt 'thing 0))) + (list 'or + (list + 'and + (list 'eq + typetag + (list 'quote name)) + (list '= + (list 'length 'thing) + (1+ slotsn))) + (list + 'memq + typetag + (list 'get + (list 'quote name) + :structure-included-in)))))) + ))))) + ;; compute accessors for NAME's slots + (multiple-value-setq + (accessors alterators keywords) + (build$accessors$for name conc-name predicate slots slotsn)) + ;; generate returned value -- not defined by the standard + (setq returned + (list + (cons 'vector + (mapcar + '(lambda (x) (list 'quote x)) + (cons name slots))))) + ;; generate code + (cons 'progn + (nconc properties functions keywords + accessors alterators returned)))))) + +(defun parse$defstruct$args (args) + "(parse$defstruct$args ARGS) => NAME OPTIONS DOCSTRING SLOTSN SLOTS INITLIST +NAME=symbol, OPTIONS=list of, DOCSTRING=string, SLOTSN=count of slots, +SLOTS=list of their names, INITLIST=alist (keyword . initform)." + (let (name ;args=(symbol...) or ((symbol...)...) + options ;args=((symbol . options) ...) + (docstring "") ;args=(head docstring . slotargs) + slotargs ;second or third cdr of args + (slotsn 0) ;number of slots + (slots '()) ;list of slot names + (initlist '())) ;list of (slot keyword . initform) + ;; extract name and options + (cond ((symbolp (car args)) ;simple name + (setq name (car args) + options '())) + ((and (listp (car args)) ;(name . options) + (symbolp (caar args))) + (setq name (caar args) + options (cdar args))) + (t + (error "first arg to `defstruct' must be symbol or (symbol ...)"))) + (setq slotargs (cdr args)) + ;; is there a docstring? + (when (stringp (car slotargs)) + (setq docstring (car slotargs) + slotargs (cdr slotargs))) + ;; now for the slots + (multiple-value-bind + (slotsn slots initlist) + (process$slots slotargs) + (values name options docstring slotsn slots initlist)))) + +(defun process$slots (slots) + "(process$slots SLOTS) => SLOTSN SLOTSLIST INITLIST +Converts a list of symbols or lists of symbol and form into the last 3 +values returned by PARSE$DEFSTRUCT$ARGS." + (let ((slotsn (length slots)) ;number of slots + slotslist ;(slot1 slot2 ...) + initlist) ;((:slot1 . init1) ...) + (do* + ((ptr slots (cdr ptr)) + (this (car ptr) (car ptr))) + ((endp ptr)) + (cond ((symbolp this) + (setq slotslist (cons this slotslist)) + (setq initlist (acons (keyword-of this) nil initlist))) + ((and (listp this) + (symbolp (car this))) + (let ((name (car this)) + (form (cadr this))) + ;; this silently ignores any slot options. bad... + (setq slotslist (cons name slotslist)) + (setq initlist (acons (keyword-of name) form initlist)))) + (t + (error "slot should be symbol or (symbol ...), not `%s'" + (prin1-to-string this))))) + (values slotsn (nreverse slotslist) (nreverse initlist)))) + +(defun parse$defstruct$options (name options slots) + "(parse$defstruct$options name OPTIONS SLOTS) => many values +A defstruct named NAME, with options list OPTIONS, has already slots SLOTS. +Parse the OPTIONS and return the updated form of the struct's slots and other +information. The values returned are: + + CONC-NAME is the string to use as prefix/suffix in the methods, + CONST is the name of the official constructor, + COPIER is the name of the structure copier, + PRED is the name of the type predicate, + MORESLOTSN is the number of slots added by :include, + MORESLOTS is the list of slots added by :include, + MOREINITS is the list of initialization forms added by :include, + INCLUDED is nil, or the list of the symbol added by :include" + (let* ((namestring (symbol-name name)) + ;; to build the return values + (conc-name (concat namestring "-")) + (const (intern (concat "make-" namestring))) + (copier (intern (concat "copy-" namestring))) + (pred (intern (concat namestring "-p"))) + (moreslotsn 0) + (moreslots '()) + (moreinits '()) + ;; auxiliaries + option-head ;When an option is not a plain + option-second ; keyword, it must be a list of + option-rest ; the form (head second . rest) + these-slotsn ;When :include is found, the + these-slots ; info about the included + these-inits ; structure is added here. + included ;NIL or (list INCLUDED) + ) + ;; Values above are the defaults. Now we read the options themselves + (dolist (option options) + ;; 2 cases arise, as options must be a keyword or a list + (cond + ((keywordp option) + (case option + (:named + ) ;ignore silently + (t + (error "can't recognize option `%s'" + (prin1-to-string option))))) + ((and (listp option) + (keywordp (setq option-head (car option)))) + (setq option-second (second option)) + (setq option-rest (nthcdr 2 option)) + (case option-head + (:conc-name + (setq conc-name + (cond + ((stringp option-second) + option-second) + ((null option-second) + "") + (t + (error "`%s' is invalid as `conc-name'" + (prin1-to-string option-second)))))) + (:copier + (setq copier + (cond + ((and (symbolp option-second) + (null option-rest)) + option-second) + (t + (error "can't recognize option `%s'" + (prin1-to-string option)))))) + + (:constructor ;no BOA-constructors allowed + (setq const + (cond + ((and (symbolp option-second) + (null option-rest)) + option-second) + (t + (error "can't recognize option `%s'" + (prin1-to-string option)))))) + (:predicate + (setq pred + (cond + ((and (symbolp option-second) + (null option-rest)) + option-second) + (t + (error "can't recognize option `%s'" + (prin1-to-string option)))))) + (:include + (unless (symbolp option-second) + (error "arg to `:include' should be a symbol, not `%s'" + (prin1-to-string option-second))) + (setq these-slotsn (get option-second :structure-slotsn) + these-slots (get option-second :structure-slots) + these-inits (get option-second :structure-initforms)) + (unless (and (numberp these-slotsn) + (> these-slotsn 0)) + (error "`%s' is not a valid structure" + (prin1-to-string option-second))) + (if included + (error "`%s' already includes `%s', can't include `%s' too" + name (car included) option-second) + (push option-second included)) + (multiple-value-bind + (xtra-slotsn xtra-slots xtra-inits) + (process$slots option-rest) + (when (> xtra-slotsn 0) + (dolist (xslot xtra-slots) + (unless (memq xslot these-slots) + (error "`%s' is not a slot of `%s'" + (prin1-to-string xslot) + (prin1-to-string option-second)))) + (setq these-inits (append xtra-inits these-inits))) + (setq moreslotsn (+ moreslotsn these-slotsn)) + (setq moreslots (append these-slots moreslots)) + (setq moreinits (append these-inits moreinits)))) + ((:print-function :type :initial-offset) + ) ;ignore silently + (t + (error "can't recognize option `%s'" + (prin1-to-string option))))) + (t + (error "can't recognize option `%s'" + (prin1-to-string option))))) + ;; Return values found + (values conc-name const copier pred + moreslotsn moreslots moreinits + included))) + +(defun simplify$inits (slots initlist) + "(simplify$inits SLOTS INITLIST) => new INITLIST +Removes from INITLIST - an ALIST - any shadowed bindings." + (let ((result '()) ;built here + key ;from the slot + ) + (dolist (slot slots) + (setq key (keyword-of slot)) + (setq result (acons key (cdr (assoc key initlist)) result))) + (nreverse result))) + +(defun extract$indices (initlist) + "(extract$indices INITLIST) => indices list +Kludge. From a list of pairs (keyword . form) build a list of pairs +of the form (keyword . position in list from 0). Useful to precompute +some of the work of MAKE$STRUCTURE$INSTANCE." + (let ((result '()) + (index 0)) + (dolist (entry initlist (nreverse result)) + (setq result (acons (car entry) index result) + index (+ index 1))))) + +(defun build$accessors$for (name conc-name predicate slots slotsn) + "(build$accessors$for NAME PREDICATE SLOTS SLOTSN) => FSETS DEFSETFS KWDS +Generate the code for accesors and defsetfs of a structure called +NAME, whose slots are SLOTS. Also, establishes the keywords for the +slots names." + (do ((i 0 (1+ i)) + (accessors '()) + (alterators '()) + (keywords '()) + (canonic "")) ;slot name with conc-name prepended + ((>= i slotsn) + (values + (nreverse accessors) (nreverse alterators) (nreverse keywords))) + (setq canonic (intern (concat conc-name (symbol-name (nth i slots))))) + (setq accessors + (cons + (list 'fset (list 'quote canonic) + (list 'function + (list 'lambda (list 'object) + (list 'cond + (list (list predicate 'object) + (list 'aref 'object (1+ i))) + (list 't + (list 'error + "`%s' is not a struct %s" + (list 'prin1-to-string + 'object) + (list 'prin1-to-string + (list 'quote + name)))))))) + accessors)) + (setq alterators + (cons + (list 'defsetf canonic + (list 'lambda (list 'object 'newval) + (list 'cond + (list (list predicate 'object) + (list 'aset 'object (1+ i) 'newval)) + (list 't + (list 'error + "`%s' not a `%s'" + (list 'prin1-to-string + 'object) + (list 'prin1-to-string + (list 'quote + name))))))) + alterators)) + (setq keywords + (cons (list 'defkeyword (keyword-of (nth i slots))) + keywords)))) + +(defun make$structure$instance (name args) + "(make$structure$instance NAME ARGS) => new struct NAME +A struct of type NAME is created, some slots might be initialized +according to ARGS (the &rest argument of MAKE-name)." + (unless (symbolp name) + (error "`%s' is not a possible name for a structure" + (prin1-to-string name))) + (let ((initforms (get name :structure-initforms)) + (slotsn (get name :structure-slotsn)) + (indices (get name :structure-indices)) + initalist ;pairlis'd on initforms + initializers ;definitive initializers + ) + ;; check sanity of the request + (unless (and (numberp slotsn) + (> slotsn 0)) + (error "`%s' is not a defined structure" + (prin1-to-string name))) + (unless (evenp (length args)) + (error "slot initializers `%s' not of even length" + (prin1-to-string args))) + ;; analyze the initializers provided by the call + (multiple-value-bind + (speckwds specvals) ;keywords and values given + (unzip-list args) ; by the user + ;; check that all the arguments are introduced by keywords + (unless (every (function keywordp) speckwds) + (error "all of the names in `%s' should be keywords" + (prin1-to-string speckwds))) + ;; check that all the keywords are known + (dolist (kwd speckwds) + (unless (numberp (cdr (assoc kwd indices))) + (error "`%s' is not a valid slot name for %s" + (prin1-to-string kwd) (prin1-to-string name)))) + ;; update initforms + (setq initalist + (pairlis speckwds + (do* ;;protect values from further evaluation + ((ptr specvals (cdr ptr)) + (val (car ptr) (car ptr)) + (result '())) + ((endp ptr) (nreverse result)) + (setq result + (cons (list 'quote val) + result))) + (copy-sequence initforms))) + ;; compute definitive initializers + (setq initializers + (do* ;;gather the values of the most definitive forms + ((ptr indices (cdr ptr)) + (key (caar ptr) (caar ptr)) + (result '())) + ((endp ptr) (nreverse result)) + (setq result + (cons (eval (cdr (assoc key initalist))) result)))) + ;; do real initialization + (apply (function vector) + (cons name initializers))))) + +;;;; end of cl-structs.el + +;;; For lisp-interaction mode, so that multiple values can be seen when passed +;;; back. Lies every now and then... + +(defvar - nil "form currently under evaluation") +(defvar + nil "previous -") +(defvar ++ nil "previous +") +(defvar +++ nil "previous ++") +(defvar / nil "list of values returned by +") +(defvar // nil "list of values returned by ++") +(defvar /// nil "list of values returned by +++") +(defvar * nil "(first) value of +") +(defvar ** nil "(first) value of ++") +(defvar *** nil "(first) value of +++") + +(defun cl-eval-print-last-sexp () + "Evaluate sexp before point; print value\(s\) into current buffer. +If the evaled form returns multiple values, they are shown one to a line. +The variables -, +, ++, +++, *, **, ***, /, //, /// have their usual meaning. + +It clears the multiple-value passing mechanism, and does not pass back +multiple values. Use this only if you are debugging cl.el and understand well +how the multiple-value stuff works, because it can be fooled into believing +that multiple values have been returned when they actually haven't, for +instance + \(identity \(values nil 1\)\) +However, even when this fails, you can trust the first printed value to be +\(one of\) the returned value\(s\)." + (interactive) + ;; top level call, can reset mvalues + (setq *mvalues-count* nil + *mvalues-values* nil) + (setq - (car (read-from-string + (buffer-substring + (let ((stab (syntax-table))) + (unwind-protect + (save-excursion + (set-syntax-table emacs-lisp-mode-syntax-table) + (forward-sexp -1) + (point)) + (set-syntax-table stab))) + (point))))) + (setq *** ** + ** * + * (eval -)) + (setq /// // + // / + / *mvalues-values*) + (setq +++ ++ + ++ + + + -) + (cond ((or (null *mvalues-count*) ;mvalues mechanism not used + (not (eq * (car *mvalues-values*)))) + (print * (current-buffer))) + ((null /) ;no values returned + (terpri (current-buffer))) + (t ;more than zero mvalues + (terpri (current-buffer)) + (mapcar (function (lambda (value) + (prin1 value (current-buffer)) + (terpri (current-buffer)))) + /))) + (setq *mvalues-count* nil ;make sure + *mvalues-values* nil)) + +;;;; More LISTS functions +;;;; + +;;; Some mapping functions on lists, commonly useful. +;;; They take no extra sequences, to go along with Emacs Lisp's MAPCAR. + +(defun mapc (function list) + "(MAPC FUNCTION LIST) => LIST +Apply FUNCTION to each element of LIST, return LIST. +Like mapcar, but called only for effect." + (let ((args list)) + (while args + (funcall function (car args)) + (setq args (cdr args)))) + list) + +(defun maplist (function list) + "(MAPLIST FUNCTION LIST) => list'ed results of FUNCTION on cdrs of LIST +Apply FUNCTION to successive sublists of LIST, return the list of the results" + (let ((args list) + results '()) + (while args + (setq results (cons (funcall function args) results) + args (cdr args))) + (nreverse results))) + +(defun mapl (function list) + "(MAPL FUNCTION LIST) => LIST +Apply FUNCTION to successive cdrs of LIST, return LIST. +Like maplist, but called only for effect." + (let ((args list)) + (while args + (funcall function args) + (setq args (cdr args))) + list)) + +(defun mapcan (function list) + "(MAPCAN FUNCTION LIST) => nconc'd results of FUNCTION on LIST +Apply FUNCTION to each element of LIST, nconc the results. +Beware: nconc destroys its first argument! See copy-list." + (let ((args list) + (results '())) + (while args + (setq results (nconc (funcall function (car args)) results) + args (cdr args))) + (nreverse results))) + +(defun mapcon (function list) + "(MAPCON FUNCTION LIST) => nconc'd results of FUNCTION on cdrs of LIST +Apply FUNCTION to successive sublists of LIST, nconc the results. +Beware: nconc destroys its first argument! See copy-list." + (let ((args list) + (results '())) + (while args + (setq results (nconc (funcall function args) results) + args (cdr args))) + (nreverse results))) + +;;; Copiers + +(defun copy-list (list) + "Build a copy of LIST" + (append list '())) + +(defun copy-tree (tree) + "Build a copy of the tree of conses TREE +The argument is a tree of conses, it is recursively copied down to +non conses. Circularity and sharing of substructure are not +necessarily preserved." + (if (consp tree) + (cons (copy-tree (car tree)) + (copy-tree (cdr tree))) + tree)) + +;;; reversals, and destructive manipulations of a list's spine + +(defun revappend (x y) + "does what (append (reverse X) Y) would, only faster" + (if (endp x) + y + (revappend (cdr x) (cons (car x) y)))) + +(defun nreconc (x y) + "does (nconc (nreverse X) Y) would, only faster +Destructive on X, be careful." + (if (endp x) + y + ;; reuse the first cons of x, making it point to y + (nreconc (cdr x) (prog1 x (rplacd x y))))) + +(defun nbutlast (list &optional n) + "Side-effected LIST truncated N+1 conses from the end. +This is the destructive version of BUTLAST. Returns () and does not +modify the LIST argument if the length of the list is not at least N." + (when (null n) (setf n 1)) + (let ((length (list-length list))) + (cond ((null length) + list) + ((< length n) + '()) + (t + (setnthcdr (- length n) list nil) + list)))) + +;;; Substitutions + +(defun subst (new old tree) + "NEW replaces OLD in a copy of TREE +Uses eql for the test." + (subst-if new (function (lambda (x) (eql x old))) tree)) + +(defun subst-if-not (new test tree) + "NEW replaces any subtree or leaf that fails TEST in a copy of TREE" + ;; (subst-if new (function (lambda (x) (not (funcall test x)))) tree) + (cond ((not (funcall test tree)) + new) + ((atom tree) + tree) + (t ;no match so far + (let ((head (subst-if-not new test (car tree))) + (tail (subst-if-not new test (cdr tree)))) + ;; If nothing changed, return originals. Else use the new + ;; components to assemble a new tree. + (if (and (eql head (car tree)) + (eql tail (cdr tree))) + tree + (cons head tail)))))) + +(defun subst-if (new test tree) + "NEW replaces any subtree or leaf that satisfies TEST in a copy of TREE" + (cond ((funcall test tree) + new) + ((atom tree) + tree) + (t ;no match so far + (let ((head (subst-if new test (car tree))) + (tail (subst-if new test (cdr tree)))) + ;; If nothing changed, return originals. Else use the new + ;; components to assemble a new tree. + (if (and (eql head (car tree)) + (eql tail (cdr tree))) + tree + (cons head tail)))))) + +(defun sublis (alist tree) + "Use association list ALIST to modify a copy of TREE +If a subtree or leaf of TREE is a key in ALIST, it is replaced by the +associated value. Not exactly Common Lisp, but close in spirit and +compatible with the native Emacs Lisp ASSOC, which uses EQUAL." + (let ((toplevel (assoc tree alist))) + (cond (toplevel ;Bingo at top + (cdr toplevel)) + ((atom tree) ;Give up on this + tree) + (t + (let ((head (sublis alist (car tree))) + (tail (sublis alist (cdr tree)))) + (if (and (eql head (car tree)) + (eql tail (cdr tree))) + tree + (cons head tail))))))) + +(defun member-if (predicate list) + "PREDICATE is applied to the members of LIST. As soon as one of them +returns true, that tail of the list if returned. Else NIL." + (catch 'found-member-if + (while (not (endp list)) + (if (funcall predicate (car list)) + (throw 'found-member-if list) + (setq list (cdr list)))) + nil)) + +(defun member-if-not (predicate list) + "PREDICATE is applied to the members of LIST. As soon as one of them +returns false, that tail of the list if returned. Else NIL." + (catch 'found-member-if-not + (while (not (endp list)) + (if (funcall predicate (car list)) + (setq list (cdr list)) + (throw 'found-member-if-not list))) + nil)) + +(defun tailp (sublist list) + "(tailp SUBLIST LIST) => True if SUBLIST is a sublist of LIST." + (catch 'tailp-found + (while (not (endp list)) + (if (eq sublist list) + (throw 'tailp-found t) + (setq list (cdr list)))) + nil)) + +;;; Suggestion of phr%widow.Berkeley.EDU@lilac.berkeley.edu + +(defmacro declare (&rest decls) + "Ignore a Common-Lisp declaration." + "declarations are ignored in this implementation") + +(defun proclaim (&rest decls) + "Ignore a Common-Lisp proclamation." + "declarations are ignored in this implementation") + +(defmacro the (type form) + "(the TYPE FORM) macroexpands to FORM +No checking is even attempted. This is just for compatibility with +Common-Lisp codes." + form) + +;;;; end of cl.el