From 67c1266e5f4269e7de58aee1261e15610685c766 Mon Sep 17 00:00:00 2001
From: Patrick Jakubowski <patrick.jakubowski@strongdm.com>
Date: Tue, 24 Sep 2024 15:41:47 -0700
Subject: [PATCH] internal/mapset: reduce the functionality of Intersection to
 just a boolean Intersects

Signed-off-by: Patrick Jakubowski <patrick.jakubowski@strongdm.com>
---
 internal/eval/evalers.go          |  2 +-
 internal/mapset/immutable.go      |  6 +++---
 internal/mapset/immutable_test.go |  6 ++----
 internal/mapset/mapset.go         |  9 ++++-----
 internal/mapset/mapset_test.go    | 12 ++----------
 5 files changed, 12 insertions(+), 23 deletions(-)

diff --git a/internal/eval/evalers.go b/internal/eval/evalers.go
index 6783666..bb864aa 100644
--- a/internal/eval/evalers.go
+++ b/internal/eval/evalers.go
@@ -1022,7 +1022,7 @@ func entityInSet(env *Env, entity types.EntityUID, parents mapset.Container[type
 	var candidate = entity
 	for {
 		if fe, ok := env.Entities[candidate]; ok {
-			if fe.Parents.Intersection(parents).Len() > 0 {
+			if fe.Parents.Intersects(parents) {
 				return true
 			}
 			fe.Parents.Iterate(func(k types.EntityUID) bool {
diff --git a/internal/mapset/immutable.go b/internal/mapset/immutable.go
index 3be21d9..357c1d9 100644
--- a/internal/mapset/immutable.go
+++ b/internal/mapset/immutable.go
@@ -15,9 +15,9 @@ func (h ImmutableMapSet[T]) Contains(item T) bool {
 	return MapSet[T](h).Contains(item)
 }
 
-// Intersection returns the items common to both h and o.
-func (h ImmutableMapSet[T]) Intersection(o Container[T]) ImmutableMapSet[T] {
-	return ImmutableMapSet[T](*MapSet[T](h).Intersection(o))
+// Intersects returns whether any items in this set exist in o
+func (h ImmutableMapSet[T]) Intersects(o Container[T]) bool {
+	return MapSet[T](h).Intersects(o)
 }
 
 // Iterate the items in the set, calling callback for each item. If the callback returns false, iteration is halted.
diff --git a/internal/mapset/immutable_test.go b/internal/mapset/immutable_test.go
index 3baf661..fc3aaee 100644
--- a/internal/mapset/immutable_test.go
+++ b/internal/mapset/immutable_test.go
@@ -97,16 +97,14 @@ func TestImmutableHashSet(t *testing.T) {
 		s1 := Immutable(1, 2, 3)
 		s2 := Immutable(2, 3, 4)
 
-		s3 := s1.Intersection(s2)
-		testutil.Equals(t, s3, Immutable(2, 3))
+		testutil.Equals(t, s1.Intersects(s2), true)
 	})
 
 	t.Run("intersection disjoint", func(t *testing.T) {
 		s1 := Immutable(1, 2)
 		s2 := Immutable(3, 4)
 
-		s3 := s1.Intersection(s2)
-		testutil.Equals(t, s3.Len(), 0)
+		testutil.Equals(t, s1.Intersects(s2), false)
 	})
 
 	t.Run("encode nil set", func(t *testing.T) {
diff --git a/internal/mapset/mapset.go b/internal/mapset/mapset.go
index 09965d2..91c4ea5 100644
--- a/internal/mapset/mapset.go
+++ b/internal/mapset/mapset.go
@@ -69,15 +69,14 @@ type Container[T comparable] interface {
 	Contains(T) bool
 }
 
-// Intersection returns the items common to both h and o.
-func (h MapSet[T]) Intersection(o Container[T]) *MapSet[T] {
-	intersection := Make[T]()
+// Intersects returns whether any items in this set exist in o
+func (h MapSet[T]) Intersects(o Container[T]) bool {
 	for item := range h.m {
 		if o.Contains(item) {
-			intersection.Add(item)
+			return true
 		}
 	}
-	return intersection
+	return false
 }
 
 // Iterate the items in the set, calling callback for each item. If the callback returns false, iteration is halted.
diff --git a/internal/mapset/mapset_test.go b/internal/mapset/mapset_test.go
index 1b23ed6..21d43df 100644
--- a/internal/mapset/mapset_test.go
+++ b/internal/mapset/mapset_test.go
@@ -130,22 +130,14 @@ func TestHashSet(t *testing.T) {
 		s1 := FromItems(1, 2, 3)
 		s2 := FromItems(2, 3, 4)
 
-		s3 := s1.Intersection(s2)
-		testutil.Equals(t, s3, FromItems(2, 3))
-
-		s4 := s1.Intersection(s2)
-		testutil.Equals(t, s4, FromItems(2, 3))
+		testutil.Equals(t, s1.Intersects(s2), true)
 	})
 
 	t.Run("intersection disjoint", func(t *testing.T) {
 		s1 := FromItems(1, 2)
 		s2 := FromItems(3, 4)
 
-		s3 := s1.Intersection(s2)
-		testutil.Equals(t, s3.Len(), 0)
-
-		s4 := s1.Intersection(s2)
-		testutil.Equals(t, s4.Len(), 0)
+		testutil.Equals(t, s1.Intersects(s2), false)
 	})
 
 	t.Run("encode nil set", func(t *testing.T) {