feat: add Filter func

maputil/map.go

@@ -45,3 +45,15 @@ func ForEach[K comparable, V any](m map[K]V, iteratee func(key K, value V)) {
 		iteratee(k, v)
 	}
 }
+
+// Filter iterates over map, return a new map contains all key and value pairs pass the predicate function
+func Filter[K comparable, V any](m map[K]V, predicate func(key K, value V) bool) map[K]V {
+	res := make(map[K]V)
+
+	for k, v := range m {
+		if predicate(k, v) {
+			res[k] = v
+		}
+	}
+	return res
+}

maputil/map_test.go

@@ -81,3 +81,25 @@ func TestForEach(t *testing.T) {
 
 	assert.Equal(10, sum)
 }
+
+func TestFilter(t *testing.T) {
+	assert := internal.NewAssert(t, "TestFilter")
+
+	m := map[string]int{
+		"a": 1,
+		"b": 2,
+		"c": 3,
+		"d": 4,
+		"e": 5,
+	}
+	isEven := func(_ string, value int) bool {
+		return value%2 == 0
+	}
+
+	acturl := Filter(m, isEven)
+
+	assert.Equal(map[string]int{
+		"b": 2,
+		"d": 4,
+	}, acturl)
+}