--- /dev/null
+;; 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")
+
+\f
+;;;; 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))))))
+\f
+;;; 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))))
+\f
+(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)))))
+
+\f
+;;; 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
+\f
+;;;; 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)))))
+\f
+;;; Temporary symbols.
+;;;
+
+(defvar *gentemp-index* 0
+ "Integer used by `gentemp' to produce new names.")
+
+(defvar *gentemp-prefix* "T$$_"
+ "Names generated by `gentemp begin' with this string by default.")
+
+(defun gentemp (&optional prefix oblist)
+ "Generate a fresh interned symbol.
+There are two optional arguments, PREFIX and OBLIST. PREFIX is the string
+that begins the new name, OBLIST is the obarray used to search for old
+names. The defaults are just right, YOU SHOULD NEVER NEED THESE ARGUMENTS
+IN YOUR OWN CODE."
+ (if (null prefix)
+ (setq prefix *gentemp-prefix*))
+ (if (null oblist)
+ (setq oblist obarray)) ;default for the intern functions
+ (let ((newsymbol nil)
+ (newname))
+ (while (not newsymbol)
+ (setq newname (concat prefix *gentemp-index*))
+ (setq *gentemp-index* (+ *gentemp-index* 1))
+ (if (not (intern-soft newname oblist))
+ (setq newsymbol (intern newname oblist))))
+ newsymbol))
+\f
+(defvar *gensym-index* 0
+ "Integer used by `gensym' to produce new names.")
+
+(defvar *gensym-prefix* "G$$_"
+ "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
+\f
+;;;; 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))
+\f
+;;; 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)))))
+
+\f
+(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
+\f
+;;;; 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)
+
+\f
+(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))))))
+
+\f
+(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))))))
+
+\f
+;;; 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)))
+\f
+;;; 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))))
+\f
+(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))
+\f
+(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
+\f
+;;;; 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 (<accessor> FORM), where <accessor> 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)
+\f
+(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
+\f
+(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))))
+\f
+;;; 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)
+\f
+;;; 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))))
+\f
+;;; 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))))
+
+\f
+;;;; 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.")
+\f
+(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)))))
+\f
+(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)))))
+\f
+;;; 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))))))
+\f
+;;; 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)))))))
+\f
+;;; 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))))))
+\f
+;;; 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)
+
+\f
+;;; 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
+\f
+;;;; 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)))))
+\f
+;;;; 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")
+\f
+;;; 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 <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*))
+\f
+;;; 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)))
+\f
+(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
+\f
+;;;; 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)))
+\f
+(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))))))))
+\f
+(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 <phs@lifia.imag.fr> 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)))))
+\f
+(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)))))))))
+\f
+(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))))))
+\f
+(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
+\f
+;;;; 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.")
+\f
+(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)))))))))
+\f
+(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)))
+\f
+;;; 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'")
+
+\f
+(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'")
+\f
+(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'")
+\f
+(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'")
+\f
+(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?
+\f
+;;; 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))))))
+\f
+;;; 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))))))
+\f
+;;; 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))))
+\f
+;;;; 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")
+
+\f
+(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$for name conc-name predicate slots slotsn))
+ ;; generate returned value -- not defined by the standard
+ (setq returned
+ (list
+ (cons 'vector
+ (mapcar
+ '(lambda (x) (list 'quote x))
+ (cons name slots)))))
+ ;; generate code
+ (cons 'progn
+ (nconc properties functions keywords
+ accessors alterators returned))))))
+\f
+(defun parse$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))))
+\f
+(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))))
+\f
+(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))))))
+\f
+ (: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$slots option-rest)
+ (when (> xtra-slotsn 0)
+ (dolist (xslot xtra-slots)
+ (unless (memq xslot these-slots)
+ (error "`%s' is not a slot of `%s'"
+ (prin1-to-string xslot)
+ (prin1-to-string option-second))))
+ (setq these-inits (append xtra-inits these-inits)))
+ (setq moreslotsn (+ moreslotsn these-slotsn))
+ (setq moreslots (append these-slots moreslots))
+ (setq moreinits (append these-inits moreinits))))
+ ((:print-function :type :initial-offset)
+ ) ;ignore silently
+ (t
+ (error "can't recognize option `%s'"
+ (prin1-to-string option)))))
+ (t
+ (error "can't recognize option `%s'"
+ (prin1-to-string option)))))
+ ;; Return values found
+ (values conc-name const copier pred
+ moreslotsn moreslots moreinits
+ included)))
+\f
+(defun simplify$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$INSTANCE."
+ (let ((result '())
+ (index 0))
+ (dolist (entry initlist (nreverse result))
+ (setq result (acons (car entry) index result)
+ index (+ index 1)))))
+\f
+(defun build$accessors$for (name conc-name predicate slots slotsn)
+ "(build$accessors$for NAME PREDICATE SLOTS SLOTSN) => FSETS DEFSETFS KWDS
+Generate the code for accesors and defsetfs of a structure called
+NAME, whose slots are SLOTS. Also, establishes the keywords for the
+slots names."
+ (do ((i 0 (1+ i))
+ (accessors '())
+ (alterators '())
+ (keywords '())
+ (canonic "")) ;slot name with conc-name prepended
+ ((>= i slotsn)
+ (values
+ (nreverse accessors) (nreverse alterators) (nreverse keywords)))
+ (setq canonic (intern (concat conc-name (symbol-name (nth i slots)))))
+ (setq accessors
+ (cons
+ (list 'fset (list 'quote canonic)
+ (list 'function
+ (list 'lambda (list 'object)
+ (list 'cond
+ (list (list predicate 'object)
+ (list 'aref 'object (1+ i)))
+ (list 't
+ (list 'error
+ "`%s' is not a struct %s"
+ (list 'prin1-to-string
+ 'object)
+ (list 'prin1-to-string
+ (list 'quote
+ name))))))))
+ accessors))
+ (setq alterators
+ (cons
+ (list 'defsetf canonic
+ (list 'lambda (list 'object 'newval)
+ (list 'cond
+ (list (list predicate 'object)
+ (list 'aset 'object (1+ i) 'newval))
+ (list 't
+ (list 'error
+ "`%s' not a `%s'"
+ (list 'prin1-to-string
+ 'object)
+ (list 'prin1-to-string
+ (list 'quote
+ name)))))))
+ alterators))
+ (setq keywords
+ (cons (list 'defkeyword (keyword-of (nth i slots)))
+ keywords))))
+\f
+(defun make$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
+\f
+;;; 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))
+\f
+;;;; 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))))
+\f
+;;; 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))
+\f
+;;; 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
projects / emacs.git / commitdiff