Making Collection,OrderedCollectin and Item array implement the ItemMatcher interface

collection.go

@@ -290,3 +290,8 @@ func FollowingNew() *Following {
 
 	return &i
 }
+
+// ItemMatches
+func (c Collection) ItemMatches(it Item) bool {
+	return c.Items.Contains(it.GetLink())
+}

collection_page.go

@@ -284,3 +284,8 @@ func ToCollectionPage(it Item) (*CollectionPage, error) {
 	}
 	return nil, errors.New("unable to convert to collection page")
 }
+
+// ItemMatches
+func (c CollectionPage) ItemMatches(it Item) bool {
+	return c.Items.Contains(it.GetLink())
+}

helpers.go

@@ -92,11 +92,7 @@ func OnCollectionIntf(it Item, fn withCollectionInterfaceFn) error {
 		if err != nil {
 			return err
 		}
-		c := Collection{
-			TotalItems: uint(len(*col)),
-			Items:      *col,
-		}
-		return fn(&c)
+		return fn(col)
 	case CollectionType:
 		col, err := ToCollection(it)
 		if err != nil {

item.go

@@ -18,3 +18,4 @@ func Flatten(it Item) Item {
 	}
 	return it
 }
+

item_collection.go

@@ -151,3 +151,7 @@ func ToItemCollection(it Item) (*ItemCollection, error) {
 	}
 	return nil, errors.New("unable to convert to item collection")
 }
+
+func (i ItemCollection) ItemMatches(it Item) bool {
+	return i.Contains(it.GetLink())
+}

ordered_collection.go

@@ -385,3 +385,8 @@ func SharesNew() *Shares {
 
 	return &i
 }
+
+// ItemMatches
+func (o OrderedCollection) ItemMatches(it Item) bool {
+	return o.OrderedItems.Contains(it.GetLink())
+}

ordered_collection_page.go

@@ -239,3 +239,8 @@ func ToOrderedCollectionPage(it Item) (*OrderedCollectionPage, error) {
 	}
 	return nil, errors.New("unable to convert to ordered collection page")
 }
+
+// ItemMatches
+func (o OrderedCollectionPage) ItemMatches(it Item) bool {
+	return o.OrderedItems.Contains(it.GetLink())
+}