--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/java/extensions/java/util/Collection.st	Sat Oct 05 01:27:31 2013 +0100
@@ -0,0 +1,182 @@
+"{ Package: 'stx:libjava' }"
+
+!
+
+!(Java classForName:'java.util.Collection') methodsFor:'* instance *'!
+
+collect:aBlock
+    "for each element in the receiver, evaluate the argument, aBlock
+     and return a new collection with the results"
+
+    |newCollection|
+
+    newCollection := self species new.
+    self do:[:element | newCollection add:(aBlock value:element)].
+    ^ newCollection
+
+    "
+     #(1 2 3 4) collect:[:n | n * 2]  
+    "
+! !
+!(Java classForName:'java.util.Collection') methodsFor:'* instance *'!
+
+detect:aBlock
+    "evaluate the argument, aBlock for each element in the receiver until
+     the block returns true; in this case return the element which caused
+     the true evaluation.
+     If none of the evaluations returns true, report an error"
+
+    ^ self detect:aBlock ifNone:[self errorNotFound]
+
+    "
+     #(1 2 3 4) detect:[:n | n odd]   
+     #(2 4 6 8) detect:[:n | n odd]  
+    "
+! !
+!(Java classForName:'java.util.Collection') methodsFor:'* instance *'!
+
+detect:aOneArgBlock ifNone:exceptionBlock
+    "evaluate the argument, aBlock for each element in the receiver until
+     the block returns true; in this case return the element which caused
+     the true evaluation.
+     If none of the evaluations returns true, return the result of the
+     evaluation of the exceptionBlock"
+
+    self do:[:each | 
+        (aOneArgBlock value:each) ifTrue:[^ each].
+    ].
+    ^ exceptionBlock value
+
+    "
+     #(1 2 3 4) detect:[:n | n odd] ifNone:['sorry']    
+     #(2 4 6 8) detect:[:n | n odd] ifNone:['sorry']     
+    "
+
+    "Modified: / 13-09-2006 / 11:17:42 / cg"
+! !
+!(Java classForName:'java.util.Collection') methodsFor:'* instance *'!
+
+do: aBlock
+    "Iterate over collection evaluating given block with each element"
+
+    | iterator |
+
+    iterator := self iterator.
+    [ iterator hasNext ] whileTrue:[
+        aBlock value: iterator next.
+    ].
+! !
+!(Java classForName:'java.util.Collection') methodsFor:'* instance *'!
+
+do:aBlock separatedBy:betweenBlock
+    "evaluate the argument, aBlock for each element.
+     Between elements (i.e. after each except for the last),
+     evaluate betweenBlock.
+     This is a utility helper for collection printers
+     (for example, to print a space between elements)."
+
+"/ could do the more hackish:
+"/
+"/    |b|
+"/
+"/    b := [ b := betweenBlock ].
+"/    self do:[:element |
+"/        b value.
+"/        aBlock value:element
+"/    ].
+"/
+"/ but that creates a block, whereas the following does not.
+
+    |first|
+
+    first := true.
+    self do:[:element |
+        first ifTrue:[
+            first := false
+        ] ifFalse:[
+            betweenBlock value.
+        ].
+        aBlock value:element
+    ].
+
+    "
+     #(1 2 3 4) do:[:el | Transcript show:el]
+                separatedBy:[ Transcript show:'-']
+
+     (Dictionary with:(1->'one') with:(2->'two'))
+         do:[:el | Transcript showCR:el printString]
+         separatedBy:[ Transcript showCR:'----']
+
+     (Dictionary with:(1->'one') with:(2->'two'))
+        associations
+         do:[:el | Transcript showCR:el printString]
+         separatedBy:[ Transcript showCR:'----']
+
+    "
+
+    "Modified: / 11.2.2000 / 11:23:15 / cg"
+! !
+!(Java classForName:'java.util.Collection') methodsFor:'* instance *'!
+
+inject:thisValue into:binaryBlock
+    "starting with thisValue for value, pass this value and each element
+     to binaryBlock, replacing value with the result returned from the block
+     in the next iteration.
+
+     See also: #fold: #reduce:"
+
+    |nextValue|
+
+    nextValue := thisValue.
+    self do: [:each | nextValue := binaryBlock value:nextValue value:each].
+    ^ nextValue
+
+    "sum up the elements of a collection:
+
+     #(1 2 3 4) inject:0 into:[:accu :element | accu + element]   
+     (1 to:10) inject:0 into:[:accu :element | accu + element]     
+
+     find the minimum:
+
+     |coll|
+     coll := #(1 99 -15 20 100).
+     coll inject:(coll first) into:[:minSoFar :element | minSoFar min:element]
+    "
+
+    "Modified: 23.4.1996 / 13:47:06 / cg"
+! !
+!(Java classForName:'java.util.Collection') methodsFor:'* instance *'!
+
+reject:aBlock
+    "return a new collection with all elements from the receiver, for which
+     the argument aBlock evaluates to false"
+
+    ^ self select:[:element | (aBlock value:element) not]
+
+    "
+     #(1 2 3 4) reject:[:e | e odd]   
+     (1 to:10) reject:[:e | e even]     
+    "
+! !
+!(Java classForName:'java.util.Collection') methodsFor:'* instance *'!
+
+select:aBlock
+    "return a new collection with all elements from the receiver, for which
+     the argument aBlock evaluates to true.
+     See also: #removeAllFoundIn: and #removeAllSuchThat:"
+
+    |newCollection|
+
+    newCollection := self species new.
+    self do:[:each |
+        (aBlock value:each) ifTrue:[newCollection add:each].
+    ].
+    ^ newCollection
+
+    "
+     #(1 2 3 4) select:[:e | e odd]   
+     (1 to:10) select:[:e | e even]     
+    "
+
+    "Modified: / 07-08-2010 / 16:26:40 / cg"
+! !