-(defmacro doseq ((elt seq &optional index) &body body)
- (let* ((nseq (gensym "seq"))
- (i (or index (gensym "i")))
- (list-body (if index
- `(let ((,i -1))
- (dolist (,elt ,nseq)
- (incf ,i)
- ,@body))
- `(dolist (,elt ,nseq)
- ,@body))))
- `(let ((,nseq ,seq))
- (if (listp ,nseq)
- ,list-body
- (dotimes (,i (length ,nseq))
- (let ((,elt (aref ,nseq ,i)))
- ,@body))))))
-
-(defun find (item seq &key key (test #'eql))
- (if key
- (doseq (x seq)
- (when (funcall test (funcall key x) item)
- (return x)))
- (doseq (x seq)
- (when (funcall test x item)
- (return x)))))
-
-(defun remove (x seq)
- (cond
- ((null seq)
- nil)
- ((listp seq)
- (let* ((head (cons nil nil))
- (tail head))
- (doseq (elt seq)
- (unless (eql x elt)
- (let ((new (list elt)))
- (rplacd tail new)
- (setq tail new))))
- (cdr head)))
- (t
- (let (vector)
- (doseq (elt seq index)
- (if (eql x elt)
- ;; Copy the beginning of the vector only when we find an element
- ;; that does not match.
- (unless vector
- (setq vector (make-array 0))
- (dotimes (i index)
- (vector-push-extend (aref seq i) vector)))
- (when vector
- (vector-push-extend elt vector))))
- (or vector seq)))))
-
-(defun remove-if (func list)
- (cond
- ((null list)
- nil)
- ((funcall func (car list))
- (remove-if func (cdr list)))
- (t
- ;;
- (cons (car list) (remove-if func (cdr list))))))
-
-(defun remove-if-not (func list)
- (cond
- ((null list)
- nil)
- ((funcall func (car list))
- (cons (car list) (remove-if-not func (cdr list))))
- (t
- (remove-if-not func (cdr list)))))
-