- linkedhashset simplification

sets/linkedhashset/iterator.go

@@ -20,7 +20,7 @@ type Iterator struct {
 
 // Iterator returns a stateful iterator whose values can be fetched by an index.
 func (set *Set) Iterator() Iterator {
-	return Iterator{iterator: set.list.Iterator()}
+	return Iterator{iterator: set.ordering.Iterator()}
 }
 
 // Next moves the iterator to the next element and returns true if there was a next element in the container.

sets/linkedhashset/linkedhashset.go

@@ -26,8 +26,8 @@ func assertSetImplementation() {
 
 // Set holds elements in go's native map
 type Set struct {
-	items map[interface{}]struct{}
-	list  *doublylinkedlist.List
+	table    map[interface{}]struct{}
+	ordering *doublylinkedlist.List
 }
 
 var itemExists = struct{}{}
@@ -35,8 +35,8 @@ var itemExists = struct{}{}
 // New instantiates a new empty set and adds the passed values, if any, to the set
 func New(values ...interface{}) *Set {
 	set := &Set{
-		items: make(map[interface{}]struct{}),
-		list:  doublylinkedlist.New(),
+		table:    make(map[interface{}]struct{}),
+		ordering: doublylinkedlist.New(),
 	}
 	if len(values) > 0 {
 		set.Add(values...)
@@ -48,13 +48,10 @@ func New(values ...interface{}) *Set {
 // Note that insertion-order is not affected if an element is re-inserted into the set.
 func (set *Set) Add(items ...interface{}) {
 	for _, item := range items {
-
-		if _, contains := set.items[item]; contains {
-			continue
+		if _, contains := set.table[item]; !contains {
+			set.table[item] = itemExists
+			set.ordering.Append(item)
 		}
-
-		set.items[item] = itemExists
-		set.list.Append(item)
 	}
 }
 
@@ -62,14 +59,11 @@ func (set *Set) Add(items ...interface{}) {
 // Slow operation, worst-case O(n^2).
 func (set *Set) Remove(items ...interface{}) {
 	for _, item := range items {
-
-		if _, contains := set.items[item]; !contains {
-			continue
+		if _, contains := set.table[item]; contains {
+			delete(set.table, item)
+			index := set.ordering.IndexOf(item)
+			set.ordering.Remove(index)
 		}
-
-		delete(set.items, item)
-		index := set.list.IndexOf(item)
-		set.list.Remove(index)
 	}
 }
 
@@ -78,7 +72,7 @@ func (set *Set) Remove(items ...interface{}) {
 // Returns true if no arguments are passed at all, i.e. set is always superset of empty set.
 func (set *Set) Contains(items ...interface{}) bool {
 	for _, item := range items {
-		if _, contains := set.items[item]; !contains {
+		if _, contains := set.table[item]; !contains {
 			return false
 		}
 	}
@@ -92,13 +86,13 @@ func (set *Set) Empty() bool {
 
 // Size returns number of elements within the set.
 func (set *Set) Size() int {
-	return set.list.Size()
+	return set.ordering.Size()
 }
 
 // Clear clears all values in the set.
 func (set *Set) Clear() {
-	set.items = make(map[interface{}]struct{})
-	set.list.Clear()
+	set.table = make(map[interface{}]struct{})
+	set.ordering.Clear()
 }
 
 // Values returns all items in the set.