Added the function GetTag.

The function returns the name of the tag on which the function was called.

field_level.go

@@ -5,7 +5,6 @@ import "reflect"
 // FieldLevel contains all the information and helper functions
 // to validate a field
 type FieldLevel interface {
-
 	// returns the top level struct, if any
 	Top() reflect.Value
 
@@ -26,6 +25,8 @@ type FieldLevel interface {
 	// returns param for validation against current field
 	Param() string
 
+	GetTag() string
+
 	// ExtractType gets the actual underlying type of field value.
 	// It will dive into pointers, customTypes and return you the
 	// underlying value and it's kind.
@@ -73,6 +74,11 @@ func (v *validate) FieldName() string {
 	return v.cf.altName
 }
 
+// GetTag returns the tag name of field
+func (v *validate) GetTag() string {
+	return v.ct.tag
+}
+
 // StructFieldName returns the struct field's name
 func (v *validate) StructFieldName() string {
 	return v.cf.name