X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;ds=sidebyside;f=src%2Fsequence.lisp;h=7f86a85127d71162fe0af2ed7d42b67197ac8f5a;hb=be500b83eef452b448bfb9225e12846908ac8fc9;hp=981f5592b58fd3f5a394220cb65ecc04d662a030;hpb=fd8bc90cbea141dc226097a8bd7fa71ba55ee481;p=jscl.git

diff --git a/src/sequence.lisp b/src/sequence.lisp
index 981f559..7f86a85 100644
--- a/src/sequence.lisp
+++ b/src/sequence.lisp
@@ -63,6 +63,22 @@
                                    :test-not test-not :test-not-p test-not-p))
         (return index)))))
 
+;; TODO: need to support &key from-end
+(defun position-if (predicate sequence
+                 &key key (start 0) end)
+  ;; TODO: Implement START and END efficiently for all the sequence
+  ;; functions.
+  (let ((end (or end (length sequence))))
+    (do-sequence (x sequence index)
+      (when (and (<= start index)
+                 (< index end)
+                 (funcall predicate (if key (funcall key x) x)))
+        (return index)))))
+
+(defun position-if-not (predicate sequence
+                 &key key (start 0) end)
+  (position-if (complement predicate) sequence :key key :start start :end end))
+
 (defun remove (x seq &key key (test #'eql testp) (test-not #'eql test-not-p))
   (cond
     ((null seq)