Merge pull request #7 from huttotw/feature/ncontains

feature/ncontains

Author: huttotw

README.md

@@ -72,6 +72,8 @@ BenchmarkGreaterThan-8|200000000|18.1 ns/op|0 B/op|0 allocs/op|
 BenchmarkGreaterThanEqual-8|300000000|13.9 ns/op|0 B/op|0 allocs/op|
 BenchmarkContains-8|50000000|73.0 ns/op|64 B/op|2 allocs/op|
 BenchmarkContainsLong50000-8|100000000|55.6 ns/op|32 B/op|1 allocs/op|
+BenchmarkNotContains-8|50000000|75.1 ns/op|64 B/op|2 allocs/op|
+BenchmarkNotContainsLong50000-8|100000000|56.2 ns/op|32 B/op|1 allocs/op|
 BenchmarkPluckShallow-8|100000000|60.2 ns/op|16 B/op|1 allocs/op|
 BenchmarkPluckDeep-8|20000000|242 ns/op|112 B/op|1 allocs/op|
 

comparators.go

@@ -164,6 +164,53 @@ func containsFloat64(a, b interface{}) bool {
 	return false
 }
 
+// notContains will return true if the b is not contained a. This will also return
+// true if a is a slice of different types than b. It will return false if a
+// is not a slice.
+func notContains(a, b interface{}) bool {
+	t1 := reflect.TypeOf(a)
+	t2 := reflect.TypeOf(b)
+
+	if t1.Kind() != reflect.Slice {
+		return false
+	}
+
+	switch t2.Kind() {
+	case reflect.String:
+		return notContainsString(a, b)
+	case reflect.Float64:
+		return notContainsFloat64(a, b)
+	default:
+		return false
+	}
+}
+
+func notContainsString(a, b interface{}) bool {
+	as, ok := a.([]interface{})
+	if !ok {
+		return false
+	}
+	for _, elem := range as {
+		if val, ok := elem.(string); ok && val == b.(string) {
+			return false
+		}
+	}
+	return true
+}
+
+func notContainsFloat64(a, b interface{}) bool {
+	as, ok := a.([]interface{})
+	if !ok {
+		return false
+	}
+	for _, elem := range as {
+		if val, ok := elem.(float64); ok && val == b.(float64) {
+			return false
+		}
+	}
+	return true
+}
+
 // oneOf will return true if b contains a
 func oneOf(a, b interface{}) bool {
 	return contains(b, a)

comparators_test.go

@@ -199,6 +199,45 @@ func BenchmarkContainsLong50000(b *testing.B) {
 	}
 }
 
+func TestNotContains(t *testing.T) {
+	cases := []testCase{
+		testCase{args: []interface{}{[]interface{}{"a", "b"}, "a"}, expected: false},
+		testCase{args: []interface{}{[]interface{}{"a", "b"}, "c"}, expected: true},
+		testCase{args: []interface{}{[]interface{}{"a", "b"}, float64(1)}, expected: true},
+		testCase{args: []interface{}{[]interface{}{float64(1), float64(2)}, float64(1)}, expected: false},
+		testCase{args: []interface{}{[]interface{}{float64(1), float64(2)}, float64(3)}, expected: true},
+		testCase{args: []interface{}{[]interface{}{float64(1.01), float64(1.02)}, float64(1.01)}, expected: false},
+	}
+
+	for i, c := range cases {
+		res := notContains(c.args[0], c.args[1])
+		if res != c.expected {
+			t.Fatalf("expected case %d to be %v, got %v", i, c.expected, res)
+		}
+	}
+}
+
+func BenchmarkNotContains(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		contains([]string{"1", "2"}, "3")
+	}
+}
+
+func BenchmarkNotContainsLong50000(b *testing.B) {
+	var list []string
+
+	// Simulate a list of postal codes
+	for i := 0; i < 50000; i++ {
+		list = append(list, fmt.Sprintf("%d", i))
+	}
+
+	b.ResetTimer()
+
+	for i := 0; i < b.N; i++ {
+		contains(list, "50000")
+	}
+}
+
 func TestOneOf(t *testing.T) {
 	cases := []testCase{
 		testCase{args: []interface{}{"a", []interface{}{"a", "b"}}, expected: true},

rule.go

@@ -14,14 +14,15 @@ const (
 // defaultComparators is a map of all the default comparators that
 // a new engine should include
 var defaultComparators = map[string]Comparator{
-	"eq":       equal,
-	"ne":       notEqual,
-	"gt":       greaterThan,
-	"gte":      greaterThanEqual,
-	"lt":       lessThan,
-	"lte":      lessThanEqual,
-	"contains": contains,
-	"oneof":    oneOf,
+	"eq":        equal,
+	"ne":        notEqual,
+	"gt":        greaterThan,
+	"gte":       greaterThanEqual,
+	"lt":        lessThan,
+	"lte":       lessThanEqual,
+	"contains":  contains,
+	"ncontains": notContains,
+	"oneof":     oneOf,
 }
 
 // Rule is a our smallest unit of measure, each rule will be