+(def!constant bell-char-code 7)
+(def!constant backspace-char-code 8)
+(def!constant tab-char-code 9)
+(def!constant line-feed-char-code 10)
+(def!constant form-feed-char-code 12)
+(def!constant return-char-code 13)
+(def!constant escape-char-code 27)
+(def!constant rubout-char-code 127)
+\f
+;;;; type-ish predicates
+
+;;; a helper function for various macros which expect clauses of a
+;;; given length, etc.
+(eval-when (:compile-toplevel :load-toplevel :execute)
+ ;; Return true if X is a proper list whose length is between MIN and
+ ;; MAX (inclusive).
+ (defun proper-list-of-length-p (x min &optional (max min))
+ ;; FIXME: This implementation will hang on circular list
+ ;; structure. Since this is an error-checking utility, i.e. its
+ ;; job is to deal with screwed-up input, it'd be good style to fix
+ ;; it so that it can deal with circular list structure.
+ (cond ((minusp max)
+ nil)
+ ((null x)
+ (zerop min))
+ ((consp x)
+ (and (plusp max)
+ (proper-list-of-length-p (cdr x)
+ (if (plusp (1- min))
+ (1- min)
+ 0)
+ (1- max))))
+ (t nil))))
+
+;;; 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))
+ (started-p nil t)
+ (z x (cdr z)))
+ ((not (and (consp z) (consp y))) nil)
+ (when (and started-p (eq y z))
+ (return t))))))
+
+;;; Is X a (possibly-improper) list of at least N elements?
+(declaim (ftype (function (t index)) list-of-length-at-least-p))
+(defun list-of-length-at-least-p (x n)
+ (or (zerop n) ; since anything can be considered an improper list of length 0
+ (and (consp x)
+ (list-of-length-at-least-p (cdr x) (1- n)))))
+
+;;; Is X is a positive prime integer?
+(defun positive-primep (x)
+ ;; This happens to be called only from one place in sbcl-0.7.0, and
+ ;; only for fixnums, we can limit it to fixnums for efficiency. (And
+ ;; if we didn't limit it to fixnums, we should use a cleverer
+ ;; algorithm, since this one scales pretty badly for huge X.)
+ (declare (fixnum x))
+ (if (<= x 5)
+ (and (>= x 2) (/= x 4))
+ (and (not (evenp x))
+ (not (zerop (rem x 3)))
+ (do ((q 6)
+ (r 1)
+ (inc 2 (logxor inc 6)) ;; 2,4,2,4...
+ (d 5 (+ d inc)))
+ ((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
+;;;;
+;;;; comment from CMU CL: "the ultimate collection macro..."
+
+;;; helper functions for COLLECT, which become the expanders of the
+;;; MACROLET definitions created by COLLECT
+;;;
+;;; COLLECT-NORMAL-EXPANDER handles normal collection macros.
+;;;
+;;; COLLECT-LIST-EXPANDER handles the list collection case. N-TAIL
+;;; is the pointer to the current tail of the list, or NIL if the list
+;;; is empty.
+(eval-when (:compile-toplevel :load-toplevel :execute)
+ (defun collect-normal-expander (n-value fun forms)
+ `(progn
+ ,@(mapcar (lambda (form) `(setq ,n-value (,fun ,form ,n-value))) forms)
+ ,n-value))
+ (defun collect-list-expander (n-value n-tail forms)
+ (let ((n-res (gensym)))
+ `(progn
+ ,@(mapcar (lambda (form)
+ `(let ((,n-res (cons ,form nil)))
+ (cond (,n-tail
+ (setf (cdr ,n-tail) ,n-res)
+ (setq ,n-tail ,n-res))
+ (t
+ (setq ,n-tail ,n-res ,n-value ,n-res)))))
+ forms)
+ ,n-value))))
+
+;;; Collect some values somehow. Each of the collections specifies a
+;;; bunch of things which collected during the evaluation of the body
+;;; of the form. The name of the collection is used to define a local
+;;; macro, a la MACROLET. Within the body, this macro will evaluate
+;;; each of its arguments and collect the result, returning the
+;;; current value after the collection is done. The body is evaluated
+;;; as a PROGN; to get the final values when you are done, just call
+;;; the collection macro with no arguments.
+;;;
+;;; INITIAL-VALUE is the value that the collection starts out with,
+;;; which defaults to NIL. FUNCTION is the function which does the
+;;; collection. It is a function which will accept two arguments: the
+;;; value to be collected and the current collection. The result of
+;;; the function is made the new value for the collection. As a
+;;; totally magical special-case, FUNCTION may be COLLECT, which tells
+;;; us to build a list in forward order; this is the default. If an
+;;; INITIAL-VALUE is supplied for COLLECT, the stuff will be RPLACD'd
+;;; onto the end. Note that FUNCTION may be anything that can appear
+;;; in the functional position, including macros and lambdas.
+(defmacro collect (collections &body body)
+ (let ((macros ())
+ (binds ()))
+ (dolist (spec collections)
+ (unless (proper-list-of-length-p spec 1 3)
+ (error "malformed collection specifier: ~S" spec))
+ (let* ((name (first spec))
+ (default (second spec))
+ (kind (or (third spec) 'collect))
+ (n-value (gensym (concatenate 'string
+ (symbol-name name)
+ "-N-VALUE-"))))
+ (push `(,n-value ,default) binds)
+ (if (eq kind 'collect)
+ (let ((n-tail (gensym (concatenate 'string
+ (symbol-name name)
+ "-N-TAIL-"))))
+ (if default
+ (push `(,n-tail (last ,n-value)) binds)
+ (push n-tail binds))
+ (push `(,name (&rest args)
+ (collect-list-expander ',n-value ',n-tail args))
+ macros))
+ (push `(,name (&rest args)
+ (collect-normal-expander ',n-value ',kind args))
+ macros))))
+ `(macrolet ,macros (let* ,(nreverse binds) ,@body))))
+\f
+;;;; some old-fashioned functions. (They're not just for old-fashioned
+;;;; code, they're also used as optimized forms of the corresponding
+;;;; general functions when the compiler can prove that they're
+;;;; equivalent.)
+
+;;; like (MEMBER ITEM LIST :TEST #'EQ)
+(defun memq (item list)
+ #!+sb-doc
+ "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
+ ;; LTN-ANALYZE-KNOWN-CALL, "Recursive known function definition". The
+ ;; comments for that error say it "is probably a botched interpreter stub".
+ ;; Rather than try to figure that out, I just rewrote this function from
+ ;; scratch. -- WHN 19990512
+ (do ((i list (cdr i)))
+ ((null i))
+ (when (eq (car i) item)
+ (return i))))
+
+;;; like (ASSOC ITEM ALIST :TEST #'EQ):
+;;; Return the first pair of ALIST where ITEM is EQ to the key of
+;;; the pair.
+(defun assq (item alist)
+ ;; KLUDGE: CMU CL defined this with
+ ;; (DECLARE (INLINE ASSOC))
+ ;; (ASSOC ITEM ALIST :TEST #'EQ))
+ ;; which is pretty, but which would have required adding awkward
+ ;; build order constraints on SBCL (or figuring out some way to make
+ ;; inline definitions installable at build-the-cross-compiler time,
+ ;; which was too ambitious for now). Rather than mess with that, we
+ ;; just define ASSQ explicitly in terms of more primitive
+ ;; operations:
+ (dolist (pair alist)
+ (when (eq (car pair) item)
+ (return pair))))
+
+;;; like (DELETE .. :TEST #'EQ):
+;;; Delete all LIST entries EQ to ITEM (destructively modifying
+;;; LIST), and return the modified LIST.
+(defun delq (item list)
+ (let ((list list))
+ (do ((x list (cdr x))
+ (splice '()))
+ ((endp x) list)
+ (cond ((eq item (car x))
+ (if (null splice)
+ (setq list (cdr x))
+ (rplacd splice (cdr x))))
+ (t (setq splice x)))))) ; Move splice along to include element.
+
+
+;;; like (POSITION .. :TEST #'EQ):
+;;; Return the position of the first element EQ to ITEM.
+(defun posq (item list)
+ (do ((i list (cdr i))
+ (j 0 (1+ j)))
+ ((null i))
+ (when (eq (car i) item)
+ (return j))))
+
+(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))
projects / sbcl.git / blobdiff