+ null-type)
+ ((cons-type-p type)
+ (cons-type-cdr-type type)))))
+\f
+;;;; FIND, POSITION, and their -IF and -IF-NOT variants
+
+;;; We want to make sure that %FIND-POSITION is inline-expanded into
+;;; %FIND-POSITION-IF only when %FIND-POSITION-IF has an inline
+;;; expansion, so we factor out the condition into this function.
+(defun check-inlineability-of-find-position-if (sequence from-end)
+ (let ((ctype (lvar-type sequence)))
+ (cond ((csubtypep ctype (specifier-type 'vector))
+ ;; It's not worth trying to inline vector code unless we
+ ;; know a fair amount about it at compile time.
+ (upgraded-element-type-specifier-or-give-up sequence)
+ (unless (constant-lvar-p from-end)
+ (give-up-ir1-transform
+ "FROM-END argument value not known at compile time")))
+ ((csubtypep ctype (specifier-type 'list))
+ ;; Inlining on lists is generally worthwhile.
+ )
+ (t
+ (give-up-ir1-transform
+ "sequence type not known at compile time")))))
+
+;;; %FIND-POSITION-IF and %FIND-POSITION-IF-NOT for LIST data
+(macrolet ((def (name condition)
+ `(deftransform ,name ((predicate sequence from-end start end key)
+ (function list t t t function)
+ *
+ :policy (> speed space))
+ "expand inline"
+ `(let ((index 0)
+ (find nil)
+ (position nil))
+ (declare (type index index))
+ (dolist (i sequence
+ (if (and end (> end index))
+ (sequence-bounding-indices-bad-error
+ sequence start end)
+ (values find position)))
+ (when (and end (>= index end))
+ (return (values find position)))
+ (when (>= index start)
+ (let ((key-i (funcall key i)))
+ (,',condition (funcall predicate key-i)
+ ;; This hack of dealing with non-NIL
+ ;; FROM-END for list data by iterating
+ ;; forward through the list and keeping
+ ;; track of the last time we found a
+ ;; match might be more screwy than what
+ ;; the user expects, but it seems to be
+ ;; allowed by the ANSI standard. (And
+ ;; if the user is screwy enough to ask
+ ;; for FROM-END behavior on list data,
+ ;; turnabout is fair play.)
+ ;;
+ ;; It's also not enormously efficient,
+ ;; calling PREDICATE and KEY more often
+ ;; than necessary; but all the
+ ;; alternatives seem to have their own
+ ;; efficiency problems.
+ (if from-end
+ (setf find i
+ position index)
+ (return (values i index))))))
+ (incf index))))))
+ (def %find-position-if when)
+ (def %find-position-if-not unless))
+
+;;; %FIND-POSITION for LIST data can be expanded into %FIND-POSITION-IF
+;;; without loss of efficiency. (I.e., the optimizer should be able
+;;; to straighten everything out.)
+(deftransform %find-position ((item sequence from-end start end key test)
+ (t list t t t t t)
+ *
+ :policy (> speed space))
+ "expand inline"
+ '(%find-position-if (let ((test-fun (%coerce-callable-to-fun test)))
+ ;; The order of arguments for asymmetric tests
+ ;; (e.g. #'<, as opposed to order-independent
+ ;; tests like #'=) is specified in the spec
+ ;; section 17.2.1 -- the O/Zi stuff there.
+ (lambda (i)
+ (funcall test-fun item i)))
+ sequence
+ from-end
+ start
+ end
+ (%coerce-callable-to-fun key)))
+
+;;; The inline expansions for the VECTOR case are saved as macros so
+;;; that we can share them between the DEFTRANSFORMs and the default
+;;; cases in the DEFUNs. (This isn't needed for the LIST case, because
+;;; the DEFTRANSFORMs for LIST are less choosy about when to expand.)
+(defun %find-position-or-find-position-if-vector-expansion (sequence-arg
+ from-end
+ start
+ end-arg
+ element
+ done-p-expr)
+ (with-unique-names (offset block index n-sequence sequence end)
+ `(let* ((,n-sequence ,sequence-arg))
+ (with-array-data ((,sequence ,n-sequence :offset-var ,offset)
+ (,start ,start)
+ (,end ,end-arg)
+ :check-fill-pointer t)
+ (block ,block
+ (macrolet ((maybe-return ()
+ ;; WITH-ARRAY-DATA has already performed bounds
+ ;; checking, so we can safely elide the checks
+ ;; in the inner loop.
+ '(let ((,element (locally (declare (optimize (insert-array-bounds-checks 0)))
+ (aref ,sequence ,index))))
+ (when ,done-p-expr
+ (return-from ,block
+ (values ,element
+ (- ,index ,offset)))))))
+ (if ,from-end
+ (loop for ,index
+ ;; (If we aren't fastidious about declaring that
+ ;; INDEX might be -1, then (FIND 1 #() :FROM-END T)
+ ;; can send us off into never-never land, since
+ ;; INDEX is initialized to -1.)
+ of-type index-or-minus-1
+ from (1- ,end) downto ,start do
+ (maybe-return))
+ (loop for ,index of-type index from ,start below ,end do
+ (maybe-return))))
+ (values nil nil))))))
+
+(def!macro %find-position-vector-macro (item sequence
+ from-end start end key test)
+ (with-unique-names (element)
+ (%find-position-or-find-position-if-vector-expansion
+ sequence
+ from-end
+ start
+ end
+ element
+ ;; (See the LIST transform for a discussion of the correct
+ ;; argument order, i.e. whether the searched-for ,ITEM goes before
+ ;; or after the checked sequence element.)
+ `(funcall ,test ,item (funcall ,key ,element)))))
+
+(def!macro %find-position-if-vector-macro (predicate sequence
+ from-end start end key)
+ (with-unique-names (element)
+ (%find-position-or-find-position-if-vector-expansion
+ sequence
+ from-end
+ start
+ end
+ element
+ `(funcall ,predicate (funcall ,key ,element)))))
+
+(def!macro %find-position-if-not-vector-macro (predicate sequence
+ from-end start end key)
+ (with-unique-names (element)
+ (%find-position-or-find-position-if-vector-expansion
+ sequence
+ from-end
+ start
+ end
+ element
+ `(not (funcall ,predicate (funcall ,key ,element))))))
+
+;;; %FIND-POSITION, %FIND-POSITION-IF and %FIND-POSITION-IF-NOT for
+;;; VECTOR data
+(deftransform %find-position-if ((predicate sequence from-end start end key)
+ (function vector t t t function)
+ *
+ :policy (> speed space))
+ "expand inline"
+ (check-inlineability-of-find-position-if sequence from-end)
+ '(%find-position-if-vector-macro predicate sequence
+ from-end start end key))
+
+(deftransform %find-position-if-not ((predicate sequence from-end start end key)
+ (function vector t t t function)
+ *
+ :policy (> speed space))
+ "expand inline"
+ (check-inlineability-of-find-position-if sequence from-end)
+ '(%find-position-if-not-vector-macro predicate sequence
+ from-end start end key))
+
+(deftransform %find-position ((item sequence from-end start end key test)
+ (t vector t t t function function)
+ *
+ :policy (> speed space))
+ "expand inline"
+ (check-inlineability-of-find-position-if sequence from-end)
+ '(%find-position-vector-macro item sequence
+ from-end start end key test))
+
+;;; logic to unravel :TEST, :TEST-NOT, and :KEY options in FIND,
+;;; POSITION-IF, etc.
+(define-source-transform effective-find-position-test (test test-not)
+ (once-only ((test test)
+ (test-not test-not))
+ `(cond
+ ((and ,test ,test-not)
+ (error "can't specify both :TEST and :TEST-NOT"))
+ (,test (%coerce-callable-to-fun ,test))
+ (,test-not
+ ;; (Without DYNAMIC-EXTENT, this is potentially horribly
+ ;; inefficient, but since the TEST-NOT option is deprecated
+ ;; anyway, we don't care.)
+ (complement (%coerce-callable-to-fun ,test-not)))
+ (t #'eql))))
+(define-source-transform effective-find-position-key (key)
+ (once-only ((key key))
+ `(if ,key
+ (%coerce-callable-to-fun ,key)
+ #'identity)))
+
+(macrolet ((define-find-position (fun-name values-index)
+ `(deftransform ,fun-name ((item sequence &key
+ from-end (start 0) end
+ key test test-not)
+ (t (or list vector) &rest t))
+ '(nth-value ,values-index
+ (%find-position item sequence
+ from-end start
+ end
+ (effective-find-position-key key)
+ (effective-find-position-test
+ test test-not))))))
+ (define-find-position find 0)
+ (define-find-position position 1))
+
+(macrolet ((define-find-position-if (fun-name values-index)
+ `(deftransform ,fun-name ((predicate sequence &key
+ from-end (start 0)
+ end key)
+ (t (or list vector) &rest t))
+ '(nth-value
+ ,values-index
+ (%find-position-if (%coerce-callable-to-fun predicate)
+ sequence from-end
+ start end
+ (effective-find-position-key key))))))
+ (define-find-position-if find-if 0)
+ (define-find-position-if position-if 1))
+
+;;; the deprecated functions FIND-IF-NOT and POSITION-IF-NOT. We
+;;; didn't bother to worry about optimizing them, except note that on
+;;; Sat, Oct 06, 2001 at 04:22:38PM +0100, Christophe Rhodes wrote on
+;;; sbcl-devel
+;;;
+;;; My understanding is that while the :test-not argument is
+;;; deprecated in favour of :test (complement #'foo) because of
+;;; semantic difficulties (what happens if both :test and :test-not
+;;; are supplied, etc) the -if-not variants, while officially
+;;; deprecated, would be undeprecated were X3J13 actually to produce
+;;; a revised standard, as there are perfectly legitimate idiomatic
+;;; reasons for allowing the -if-not versions equal status,
+;;; particularly remove-if-not (== filter).
+;;;
+;;; This is only an informal understanding, I grant you, but
+;;; perhaps it's worth optimizing the -if-not versions in the same
+;;; way as the others?
+;;;
+;;; FIXME: Maybe remove uses of these deprecated functions within the
+;;; implementation of SBCL.
+(macrolet ((define-find-position-if-not (fun-name values-index)
+ `(deftransform ,fun-name ((predicate sequence &key
+ from-end (start 0)
+ end key)
+ (t (or list vector) &rest t))
+ '(nth-value
+ ,values-index
+ (%find-position-if-not (%coerce-callable-to-fun predicate)
+ sequence from-end
+ start end
+ (effective-find-position-key key))))))
+ (define-find-position-if-not find-if-not 0)
+ (define-find-position-if-not position-if-not 1))
+
+(macrolet ((define-trimmer-transform (fun-name leftp rightp)
+ `(deftransform ,fun-name ((char-bag string)
+ (t simple-string))
+ (let ((find-expr
+ (if (constant-lvar-p char-bag)
+ ;; If the bag is constant, use MEMBER
+ ;; instead of FIND, since we have a
+ ;; deftransform for MEMBER that can
+ ;; open-code all of the comparisons when
+ ;; the list is constant. -- JES, 2007-12-10
+ `(not (member (schar string index)
+ ',(coerce (lvar-value char-bag) 'list)
+ :test #'char=))
+ '(not (find (schar string index) char-bag :test #'char=)))))
+ `(flet ((char-not-in-bag (index)
+ ,find-expr))
+ (let* ((end (length string))
+ (left-end (if ,',leftp
+ (do ((index 0 (1+ index)))
+ ((or (= index (the fixnum end))
+ (char-not-in-bag index))
+ index)
+ (declare (fixnum index)))
+ 0))
+ (right-end (if ,',rightp
+ (do ((index (1- end) (1- index)))
+ ((or (< index left-end)
+ (char-not-in-bag index))
+ (1+ index))
+ (declare (fixnum index)))
+ end)))
+ (if (and (eql left-end 0)
+ (eql right-end (length string)))
+ string
+ (subseq string left-end right-end))))))))
+ (define-trimmer-transform string-left-trim t nil)
+ (define-trimmer-transform string-right-trim nil t)
+ (define-trimmer-transform string-trim t t))
+