(1- max))))
(t nil))))
-;;; Is X a circular list?
-(defun circular-list-p (x)
+;;; Is X a list containing a cycle?
+(defun cyclic-list-p (x)
(and (listp x)
(labels ((safe-cddr (x) (if (listp (cdr x)) (cddr x))))
(do ((y x (safe-cddr y))
((or (= r 0) (> d q)) (/= r 0))
(declare (fixnum inc))
(multiple-value-setq (q r) (truncate x d))))))
+
+;;; Could this object contain other objects? (This is important to
+;;; the implementation of things like *PRINT-CIRCLE* and the dumper.)
+(defun compound-object-p (x)
+ (or (consp x)
+ (typep x 'instance)
+ (typep x '(array t *))))
\f
;;;; the COLLECT macro
;;;;
;;; like (MEMBER ITEM LIST :TEST #'EQ)
(defun memq (item list)
#!+sb-doc
- "Returns tail of LIST beginning with first element EQ to ITEM."
+ "Return tail of LIST beginning with first element EQ to ITEM."
;; KLUDGE: These could be and probably should be defined as
;; (MEMBER ITEM LIST :TEST #'EQ)),
;; but when I try to cross-compile that, I get an error from
(declaim (inline neq))
(defun neq (x y)
(not (eq x y)))
+
+;;; not really an old-fashioned function, but what the calling
+;;; convention should've been: like NTH, but with the same argument
+;;; order as in all the other dereferencing functions, with the
+;;; collection first and the index second
+(declaim (inline nth-but-with-sane-arg-order))
+(declaim (ftype (function (list index) t) nth-but-with-sane-arg-order))
+(defun nth-but-with-sane-arg-order (list index)
+ (nth index list))
\f
;;;; miscellaneous iteration extensions
;;;; various operations on names
;;; Is NAME a legal function name?
-(defun legal-function-name-p (name)
+(defun legal-fun-name-p (name)
(or (symbolp name)
(and (consp name)
(eq (car name) 'setf)
;;; Given a function name, return the name for the BLOCK which
;;; encloses its body (e.g. in DEFUN, DEFINE-COMPILER-MACRO, or FLET).
-(declaim (ftype (function ((or symbol cons)) symbol) function-name-block-name))
-(defun function-name-block-name (function-name)
- (cond ((symbolp function-name)
- function-name)
- ((and (consp function-name)
- (= (length function-name) 2)
- (eq (first function-name) 'setf))
- (second function-name))
+(declaim (ftype (function ((or symbol cons)) symbol) fun-name-block-name))
+(defun fun-name-block-name (fun-name)
+ (cond ((symbolp fun-name)
+ fun-name)
+ ((and (consp fun-name)
+ (= (length fun-name) 2)
+ (eq (first fun-name) 'setf))
+ (second fun-name))
(t
- (error "not legal as a function name: ~S" function-name))))
+ (error "not legal as a function name: ~S" fun-name))))
(defun looks-like-name-of-special-var-p (x)
(and (symbolp x)
(char= #\* (aref name 0))
(char= #\* (aref name (1- (length name))))))))
-;;; ANSI guarantees that some symbols are self-evaluating. This
-;;; function is to be called just before a change which would affect
-;;; that. (We don't absolutely have to call this function before such
-;;; changes, since such changes are given as undefined behavior. In
-;;; particular, we don't if the runtime cost would be annoying. But
-;;; otherwise it's nice to do so.)
-(defun about-to-modify (symbol)
+;;; Some symbols are defined by ANSI to be self-evaluating. Return
+;;; non-NIL for such symbols (and make the non-NIL value a traditional
+;;; message, for use in contexts where the user asks us to change such
+;;; a symbol).
+(defun symbol-self-evaluating-p (symbol)
(declare (type symbol symbol))
(cond ((eq symbol t)
- (error "Veritas aeterna. (can't change T)"))
+ "Veritas aeterna. (can't change T)")
((eq symbol nil)
- (error "Nihil ex nihil. (can't change NIL)"))
+ "Nihil ex nihil. (can't change NIL)")
((keywordp symbol)
- (error "Keyword values can't be changed."))
- ;; (Just because a value is CONSTANTP is not a good enough
- ;; reason to complain here, because we want DEFCONSTANT to
- ;; be able to use this function, and it's legal to DEFCONSTANT
- ;; a constant as long as the new value is EQL to the old
- ;; value.)
- ))
+ "Keyword values can't be changed.")
+ (t
+ nil)))
+
+;;; This function is to be called just before a change which would
+;;; affect the symbol value. (We don't absolutely have to call this
+;;; function before such changes, since such changes are given as
+;;; undefined behavior. In particular, we don't if the runtime cost
+;;; would be annoying. But otherwise it's nice to do so.)
+(defun about-to-modify-symbol-value (symbol)
+ (declare (type symbol symbol))
+ (let ((reason (symbol-self-evaluating-p symbol)))
+ (when reason
+ (error reason)))
+ ;; (Note: Just because a value is CONSTANTP is not a good enough
+ ;; reason to complain here, because we want DEFCONSTANT to be able
+ ;; to use this function, and it's legal to DEFCONSTANT a constant as
+ ;; long as the new value is EQL to the old value.)
+ (values))
+
;;; If COLD-FSET occurs not at top level, just treat it as an ordinary
;;; assignment. That way things like
;;; error indicating that a required &KEY argument was not supplied.
;;; This function is also useful for DEFSTRUCT slot defaults
;;; corresponding to required arguments.
-(declaim (ftype (function () nil) required-argument))
-(defun required-argument ()
+(declaim (ftype (function () nil) required-arg))
+(defun required-arg ()
#!+sb-doc
- (/show0 "entering REQUIRED-ARGUMENT")
+ (/show0 "entering REQUIRED-ARG")
(error "A required &KEY or &OPTIONAL argument was not supplied."))
;;; like CL:ASSERT and CL:CHECK-TYPE, but lighter-weight
projects / sbcl.git / blobdiff