Fixing implementation of union, difference, and intersection tests

src/Containers-UniqueOrdered-Tests/CTSmallOrderedSetTest.class.st

@@ -123,3 +123,52 @@ CTSmallOrderedSetTest >> testSize [
 	collection addAll: #(2 1 1).
 	self assert: collection size equals: 2.
 ]
+
+{ #category : #testing }
+CTSmallOrderedSetTest >> testUnion[
+    "Tests the union operation of CTSmallOrderedSet to ensure it combines two sets, maintaining uniqueness and preserving the order of elements."
+    "scope: class-variables  &  instance-variables: collection"
+
+    | set1 set2 result |
+    set1 := CTSmallOrderedSet withAll: #(1 2 3).
+    set2 := CTSmallOrderedSet withAll: #(2 3 4).
+    result := set1 union: set2.
+
+    self assert: result size equals: 4.
+    self assert: (result includes: 1).
+    self assert: (result includes: 2).
+    self assert: (result includes: 3).
+    self assert: (result includes: 4).
+
+    "Test order preservation"
+    self assert: result asArray equals: #(1 2 3 4).
+]
+
+{ #category : #testing }
+CTSmallOrderedSetTest >> testDifference [
+    | set1 set2 result |
+    set1 := CTSmallOrderedSet withAll: #(1 2 3 4).
+    set2 := CTSmallOrderedSet withAll: #(2 4).
+    result := set1 difference: set2.
+
+    self assert: result size equals: 2.
+    self assert: (result includes: 1).
+    self assert: (result includes: 3).
+    self deny: (result includes: 2).
+    self deny: (result includes: 4).
+]
+
+{ #category : #testing }
+CTSmallOrderedSetTest >> testIntersection [
+    | set1 set2 result |
+    set1 := CTSmallOrderedSet withAll: #(1 2 3 4).
+    set2 := CTSmallOrderedSet withAll: #(2 4 5).
+    result := set1 intersection: set2.
+
+    self assert: result size equals: 2.
+    self assert: (result includes: 2).
+    self assert: (result includes: 4).
+    self deny: (result includes: 1).
+    self deny: (result includes: 3).
+    self deny: (result includes: 5).
+]

src/Containers-UniqueOrdered/CTSmallOrderedSet.class.st

@@ -139,3 +139,35 @@ CTSmallOrderedSet >> removeIndex: index [
 CTSmallOrderedSet >> size [
 	^ size
 ]
+
+{ #category : #operations }
+CTSmallOrderedSet >> union: aCollection [
+    "Return a new set containing all elements from self and aCollection"
+    ^ self copy addAll: aCollection; yourself
+]
+
+{ #category : #operations }
+CTSmallOrderedSet >> difference: aCollection [
+    "Return a new set containing elements in self that are not in aCollection"
+    | result |
+    result := self copy.
+    aCollection do: [ :each | result remove: each ifAbsent: [  ] ].
+    ^ result
+]
+
+{ #category : #operations }
+CTSmallOrderedSet >> intersection: aCollection [
+    "Return a new set containing elements present in both self and aCollection"
+    | result |
+    result := self class new.
+    self do: [ :each | 
+        (aCollection includes: each) ifTrue: [ 
+            result add: each ] ].
+    ^ result
+]
+
+{ #category : #converting }
+CTSmallOrderedSet >> asArray[
+	"Return an array containing all elements in the order they are stored."
+	^ table copyFrom: 1 to: size
+]