move extension method

src/Roassal-Layouts/SequenceableCollection.extension.st

@@ -8,3 +8,27 @@ SequenceableCollection >> rsSwapElement: u withElement: v [
 	self at: index2 put: u.
 	self at: index1 put: v
 ]
+
+{ #category : #'*Roassal-Layouts' }
+SequenceableCollection >> sortedAs: aSortBlockOrSymbol [
+	"Answer a SortedCollection whose elements are the elements of the
+	receiver. The sort order is defined by the argument, aSortBlock."
+
+	| aSortedCollection aSortBlock |
+	aSortedCollection := SortedCollection new: self size.
+	aSortBlock :=
+		aSortBlockOrSymbol isSymbol
+			ifTrue: [ [:a :b | |t1 t2|
+							t1 := (a perform: aSortBlockOrSymbol).
+							t2 := (b perform: aSortBlockOrSymbol).
+							((t1 isKindOf: Boolean) and: [t2 isKindOf: Boolean])
+								ifTrue: [ t1 ]
+								ifFalse: [ t1 < t2 ] ] ]
+			ifFalse: [
+				(aSortBlockOrSymbol numArgs = 1)
+					ifTrue: [ [ :v1 :v2 | (aSortBlockOrSymbol value: v1) < (aSortBlockOrSymbol value: v2) ] ]
+					ifFalse: [ aSortBlockOrSymbol ] ].
+	aSortedCollection sortBlock: aSortBlock.
+	aSortedCollection addAll: self.
+	^ aSortedCollection
+]