--- a/SequenceableCollection.st	Tue Aug 25 07:04:02 2015 +0200
+++ b/SequenceableCollection.st	Sun Aug 30 06:37:05 2015 +0200
@@ -751,6 +751,7 @@
     ^ self replaceFrom:start to:stop with:anArray startingAt:repStart
 ! !
 
+
 !SequenceableCollection methodsFor:'accessing'!
 
 after:anObject
@@ -7638,6 +7639,7 @@
     "Created: 14.2.1997 / 16:13:03 / cg"
 ! !
 
+
 !SequenceableCollection methodsFor:'searching'!
 
 detect:aBlock startingAt:startIndex
@@ -7678,6 +7680,51 @@
     "Created: / 21.10.1998 / 18:46:01 / cg"
 !
 
+detectLast:aBlock
+    "find the last element, for which evaluation of the argument, aBlock returns true.
+     If none does so, report an error"
+
+    ^ self detectLast:aBlock startingAt:self size ifNone:[self errorNotFound]
+
+    "
+     #(11 12 13 14) detectLast:[:n | n odd] 
+     #(12 14 16 18) detectLast:[:n | n odd] ifNone:'sorry' 
+    "
+!
+
+detectLast:aBlock startingAt:startIndex
+    "find the last element, for which evaluation of the argument, aBlock returns true.
+     Start the backward search at startIndex.
+     If none does so, report an error"
+
+    ^ self detectLast:aBlock startingAt:startIndex ifNone:[self errorNotFound]
+
+    "
+     #(11 12 13 14) detectLast:[:n | n odd] startingAt:3
+     #(12 14 16 18) detectLast:[:n | n odd] startingAt:3
+    "
+
+    "Created: / 21.10.1998 / 18:47:28 / cg"
+!
+
+detectLast:aBlock startingAt:startIndex ifNone:exceptionBlock
+    "find the last element, for which evaluation of the argument, aBlock returns true.
+     Start the backward search at startIndex.
+     If none does so, return the evaluation of exceptionBlock"
+
+    self from:startIndex to:1 by:-1 do:[:el |
+        (aBlock value:el) ifTrue:[
+            ^ el
+        ].
+    ].
+    ^ exceptionBlock value
+
+    "
+     #(11 12 13 14) detectLast:[:n | n odd] startingAt:3 ifNone:['sorry']
+     #(12 14 16 18) detectLast:[:n | n odd] startingAt:3 ifNone:['sorry']
+    "
+!
+
 findFirst:aBlock ifNone:exceptionalValue
     "find the index of the first element, for which evaluation of the argument, aBlock returns true.
      Return its index or the value from exceptionalValue if none detected.