removing unnecessary utility functions

diff/ignore.go

@@ -6,12 +6,6 @@ func Ignore() (Differ, error) {
 	return ignore{}, nil
 }
 
-func IsIgnore(d Differ) bool {
-	_, ok := d.(ignore)
-
-	return ok
-}
-
 func (t ignore) Diff() Type {
 	return Identical
 }

diff/map.go

@@ -70,12 +70,6 @@ func newMap(lhs, rhs interface{}) (mapDiff, error) {
 	}, nil
 }
 
-func IsMap(d Differ) bool {
-	_, ok := d.(mapDiff)
-
-	return ok
-}
-
 func mapTypesDiffer(lhs, rhs interface{}) (bool, error) {
 	if lhs == nil {
 		return true, ErrInvalidType{Value: lhs, For: "map"}
@@ -230,12 +224,6 @@ func getKeys(lhs, rhs reflect.Value) []reflect.Value {
 	return keys
 }
 
-func IsMapMissing(d Differ) bool {
-	_, ok := d.(mapMissing)
-
-	return ok
-}
-
 func (m mapMissing) Diff() Type {
 	return ContentDiffer
 }
@@ -251,12 +239,6 @@ func (m mapMissing) StringIndent(key, prefix string, conf Output) string {
 		"\n+" + prefix + key
 }
 
-func IsMapExcess(d Differ) bool {
-	_, ok := d.(mapExcess)
-
-	return ok
-}
-
 func (e mapExcess) Diff() Type {
 	return ContentDiffer
 }

diff/scalar.go

@@ -10,12 +10,6 @@ type scalar struct {
 	rhs interface{}
 }
 
-func IsScalar(d Differ) bool {
-	_, ok := d.(scalar)
-
-	return ok
-}
-
 func (s scalar) Diff() Type {
 	lhsVal := reflect.ValueOf(s.lhs)
 	rhsVal := reflect.ValueOf(s.rhs)

diff/slice.go

@@ -68,12 +68,6 @@ func newSlice(lhs, rhs interface{}) (Differ, error) {
 	}, nil
 }
 
-func IsSlice(d Differ) bool {
-	_, ok := d.(slice)
-
-	return ok
-}
-
 func sliceTypesDiffer(lhs, rhs interface{}) (bool, error) {
 	if lhs == nil {
 		return true, ErrInvalidType{Value: lhs, For: "slice"}
@@ -165,12 +159,6 @@ func (s slice) Walk(path string, fn WalkFn) error {
 	return nil
 }
 
-func IsSliceMissing(d Differ) bool {
-	_, ok := d.(sliceMissing)
-
-	return ok
-}
-
 func (m sliceMissing) Diff() Type {
 	return ContentDiffer
 }
@@ -190,12 +178,6 @@ func (e sliceExcess) Diff() Type {
 	return ContentDiffer
 }
 
-func IsSliceExcess(d Differ) bool {
-	_, ok := d.(sliceExcess)
-
-	return ok
-}
-
 func (e sliceExcess) Strings() []string {
 	return []string{
 		fmt.Sprintf("+ %T %v", e.value, e.value),

diff/types.go

@@ -9,12 +9,6 @@ type types struct {
 	rhs interface{}
 }
 
-func IsTypes(d Differ) bool {
-	_, ok := d.(types)
-
-	return ok
-}
-
 func (t types) Diff() Type {
 	return TypesDiffer
 }

diff/walk_test.go

@@ -67,7 +67,7 @@ func TestWalkError(t *testing.T) {
 		}
 
 		_, err = Walk(d, func(_, diff Differ, _ string) (Differ, error) {
-			if IsScalar(diff) {
+			if _, ok := diff.(scalar); ok {
 				return nil, expectedErr
 			}