diff --git a/pkg/is/is.go b/pkg/is/is.go
new file mode 100644
index 0000000..379dd93
--- /dev/null
+++ b/pkg/is/is.go
@@ -0,0 +1,607 @@
+package is
+
+import (
+	"encoding/json"
+	"net"
+	"net/url"
+	"os"
+	"reflect"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// Email 验证给出的字符串是不是有效的邮箱地址
+func Email(str string) bool {
+	return emailRegex.MatchString(str)
+}
+
+// E164 判断给出的字符串是否符合 e.164 规范的手机号码
+func E164(str string) bool {
+	return e164Regex.MatchString(str)
+}
+
+// PhoneNumber 判断给出的字符串是否符合中国大陆规范的手机号码
+func PhoneNumber(str string) bool {
+	return phoneNumberRegex.MatchString(str)
+}
+
+// Semver 判断给出的字符串是否符合语义化版本号规范
+func Semver(str string) bool {
+	return semverRegex.MatchString(str)
+}
+
+// Base64 判断给出的字符串是否为base64数据
+func Base64(str string) bool {
+	return base64Regex.MatchString(str)
+}
+
+// URL 判断给出的字符串是否为有效的URL
+func URL(s string) bool {
+	var i int
+	// checks needed as of Go 1.6 because of change https://github.com/golang/go/commit/617c93ce740c3c3cc28cdd1a0d712be183d0b328#diff-6c2d018290e298803c0c9419d8739885L195
+	// emulate browser and strip the '#' suffix prior to validation. see issue-#237
+	if i = strings.Index(s, "#"); i > -1 {
+		s = s[:i]
+	}
+	if len(s) == 0 {
+		return false
+	}
+	u, err := url.ParseRequestURI(s)
+	if err != nil || u.Scheme == "" {
+		return false
+	}
+	return true
+}
+
+// Base64URL 判断给出的字符串是否为有效且安全的 base64URL
+func Base64URL(str string) bool {
+	return base64URLRegex.MatchString(str)
+}
+
+// JWT is the validation function for validating if the current field's value is a valid JWT string.
+func JWT(str string) bool {
+	return jWTRegex.MatchString(str)
+}
+
+// UUID5 is the validation function for validating if the field's value is a valid v5 UUID.
+func UUID5(str string) bool {
+	return uUID5Regex.MatchString(str)
+}
+
+// UUID4 is the validation function for validating if the field's value is a valid v4 UUID.
+func UUID4(str string) bool {
+	return uUID4Regex.MatchString(str)
+}
+
+// UUID3 is the validation function for validating if the field's value is a valid v3 UUID.
+func UUID3(str string) bool {
+	return uUID3Regex.MatchString(str)
+}
+
+// UUID is the validation function for validating if the field's value is a valid UUID of any version.
+func UUID(str string) bool {
+	return uUIDRegex.MatchString(str)
+}
+
+// ULID is the validation function for validating if the field's value is a valid ULID.
+func ULID(str string) bool {
+	return uLIDRegex.MatchString(str)
+}
+
+// MD4 is the validation function for validating if the field's value is a valid MD4.
+func MD4(str string) bool {
+	return md4Regex.MatchString(str)
+}
+
+// MD5 is the validation function for validating if the field's value is a valid MD5.
+func MD5(str string) bool {
+	return md5Regex.MatchString(str)
+}
+
+// SHA256 is the validation function for validating if the field's value is a valid SHA256.
+func SHA256(str string) bool {
+	return sha256Regex.MatchString(str)
+}
+
+// SHA384 is the validation function for validating if the field's value is a valid SHA384.
+func SHA384(str string) bool {
+	return sha384Regex.MatchString(str)
+}
+
+// SHA512 is the validation function for validating if the field's value is a valid SHA512.
+func SHA512(str string) bool {
+	return sha512Regex.MatchString(str)
+}
+
+// ASCII is the validation function for validating if the field's value is a valid ASCII character.
+func ASCII(str string) bool {
+	return aSCIIRegex.MatchString(str)
+}
+
+// Alpha is the validation function for validating if the current field's value is a valid alpha value.
+func Alpha(str string) bool {
+	return alphaRegex.MatchString(str)
+}
+
+// Alphanumeric is the validation function for validating if the current field's value is a valid alphanumeric value.
+func Alphanumeric(str string) bool {
+	return alphaNumericRegex.MatchString(str)
+}
+
+// AlphaUnicode is the validation function for validating if the current field's value is a valid alpha unicode value.
+func AlphaUnicode(str string) bool {
+	return alphaUnicodeRegex.MatchString(str)
+}
+
+// AlphanumericUnicode is the validation function for validating if the current field's value is a valid alphanumeric unicode value.
+func AlphanumericUnicode(str string) bool {
+	return alphaUnicodeNumericRegex.MatchString(str)
+}
+
+// Numeric is the validation function for validating if the current field's value is a valid numeric value.
+func Numeric[T any](t T) bool {
+	ctx := reflect.ValueOf(t)
+	switch ctx.Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64,
+		reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr,
+		reflect.Float32, reflect.Float64:
+		return true
+	default:
+		return numericRegex.MatchString(ctx.String())
+	}
+}
+
+// Number is the validation function for validating if the current field's value is a valid number.
+func Number[T any](t T) bool {
+	rv := reflect.ValueOf(t)
+	switch rv.Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64,
+		reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr,
+		reflect.Float32, reflect.Float64:
+		return true
+	default:
+		return numberRegex.MatchString(rv.String())
+	}
+}
+
+// Boolean is the validation function for validating if the current field's value can be safely converted to a boolean.
+func Boolean[T any](t T) bool {
+	ref := reflect.ValueOf(t)
+	switch ref.Kind() {
+	case reflect.String:
+		switch ref.String() {
+		case "1", "yes", "YES", "Yes", "on", "ON", "On", "true", "TRUE", "True",
+			"0", "no", "NO", "No", "", "off", "OFF", "Off", "false", "FALSE", "False":
+			return true
+		default:
+			return false
+		}
+	case reflect.Int, reflect.Int32, reflect.Int64:
+		n := ref.Int()
+		return n == 0 || n == 1
+	case reflect.Uint, reflect.Uint32, reflect.Uint64:
+		n := ref.Uint()
+		return n == 0 || n == 1
+	case reflect.Bool:
+		return ref.Bool()
+	}
+	return false
+}
+
+// Default is the opposite of required aka HasValue
+func Default(val any) bool {
+	return !HasValue(val)
+}
+
+// HasValue is the validation function for validating if the current field's value is not the default static value.
+func HasValue(val any) bool {
+	rv := reflect.ValueOf(val)
+	switch rv.Kind() {
+	case reflect.Slice, reflect.Map, reflect.Ptr, reflect.Interface, reflect.Chan, reflect.Func:
+		return !rv.IsNil()
+	default:
+		return rv.IsValid() && rv.Interface() != reflect.Zero(rv.Type()).Interface()
+	}
+}
+
+// Hexadecimal is the validation function for validating if the current field's value is a valid hexadecimal.
+func Hexadecimal(str string) bool {
+	return hexadecimalRegex.MatchString(str)
+}
+
+// HEXColor is the validation function for validating if the current field's value is a valid HEX color.
+func HEXColor(str string) bool {
+	return hexColorRegex.MatchString(str)
+}
+
+// RGB is the validation function for validating if the current field's value is a valid RGB color.
+func RGB(str string) bool {
+	return rgbRegex.MatchString(str)
+}
+
+// RGBA is the validation function for validating if the current field's value is a valid RGBA color.
+func RGBA(str string) bool {
+	return rgbaRegex.MatchString(str)
+}
+
+// HSL is the validation function for validating if the current field's value is a valid HSL color.
+func HSL(str string) bool {
+	return hslRegex.MatchString(str)
+}
+
+// HSLA is the validation function for validating if the current field's value is a valid HSLA color.
+func HSLA(str string) bool {
+	return hslaRegex.MatchString(str)
+}
+
+func Color(str string) bool {
+	return HEXColor(str) || HSLA(str) || HSL(str) || RGB(str) || RGBA(str)
+}
+
+// Latitude is the validation function for validating if the field's value is a valid latitude coordinate.
+func Latitude[T any](t T) bool {
+	ref := reflect.ValueOf(t)
+	var v string
+	switch ref.Kind() {
+	case reflect.String:
+		v = ref.String()
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		v = strconv.FormatInt(ref.Int(), 10)
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+		v = strconv.FormatUint(ref.Uint(), 10)
+	case reflect.Float32:
+		v = strconv.FormatFloat(ref.Float(), 'f', -1, 32)
+	case reflect.Float64:
+		v = strconv.FormatFloat(ref.Float(), 'f', -1, 64)
+	default:
+		//fmt.Errorf("bad ref type %T", ref.Interface())
+		return false
+	}
+	return latitudeRegex.MatchString(v)
+}
+
+// Longitude is the validation function for validating if the field's value is a valid longitude coordinate.
+func Longitude[T any](t T) bool {
+	ref := reflect.ValueOf(t)
+	var v string
+	switch ref.Kind() {
+	case reflect.String:
+		v = ref.String()
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		v = strconv.FormatInt(ref.Int(), 10)
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+		v = strconv.FormatUint(ref.Uint(), 10)
+	case reflect.Float32:
+		v = strconv.FormatFloat(ref.Float(), 'f', -1, 32)
+	case reflect.Float64:
+		v = strconv.FormatFloat(ref.Float(), 'f', -1, 64)
+	default:
+		//fmt.Errorf("bad field type %T", ref.Interface())
+		return false
+	}
+	return longitudeRegex.MatchString(v)
+}
+
+// JSON is the validation function for validating if the current field's value is a valid json string.
+func JSON[T any](t T) bool {
+	rv := reflect.ValueOf(t)
+	if rv.Type() == bytesType {
+		return json.Valid(rv.Bytes())
+	}
+	if rv.Kind() == reflect.String {
+		return json.Valid([]byte(rv.String()))
+	}
+	return false
+}
+
+func Datetime(str, layout string) bool {
+	_, err := time.Parse(layout, str)
+	return err == nil
+}
+
+// Timezone is the validation function for validating if the current field's value is a valid time zone string.
+func Timezone(str string) bool {
+	// empty value is converted to UTC by time.LoadLocation but disallow it as it is not a valid time zone name
+	if str == "" {
+		return false
+	}
+
+	// Local value is converted to the current system time zone by time.LoadLocation but disallow it as it is not a valid time zone name
+	if strings.ToLower(str) == "local" {
+		return false
+	}
+
+	_, err := time.LoadLocation(str)
+	return err == nil
+}
+
+// IPv4 is the validation function for validating if a value is a valid v4 IP address.
+func IPv4(str string) bool {
+	ip := net.ParseIP(str)
+	return ip != nil && ip.To4() != nil
+}
+
+// IPv6 is the validation function for validating if the field's value is a valid v6 IP address.
+func IPv6(str string) bool {
+	ip := net.ParseIP(str)
+	return ip != nil && ip.To4() == nil
+}
+
+// IP is the validation function for validating if the field's value is a valid v4 or v6 IP address.
+func IP(str string) bool {
+	ip := net.ParseIP(str)
+	return ip != nil
+}
+
+// MAC is the validation function for validating if the field's value is a valid MAC address.
+func MAC(str string) bool {
+	_, err := net.ParseMAC(str)
+	return err == nil
+}
+
+// Lowercase is the validation function for validating if the current field's value is a lowercase string.
+func Lowercase(str string) bool {
+	if str == "" {
+		return false
+	}
+	return str == strings.ToLower(str)
+}
+
+// Uppercase is the validation function for validating if the current field's value is an uppercase string.
+func Uppercase(str string) bool {
+	if str == "" {
+		return false
+	}
+	return str == strings.ToUpper(str)
+}
+
+// Empty checks if a value is empty or not.
+// A value is considered empty if
+// - integer, float: zero
+// - bool: false
+// - string, array: len() == 0
+// - slice, map: nil or len() == 0
+// - interface, pointer: nil or the referenced value is empty
+func Empty[T any](t T) bool {
+	rv := reflect.ValueOf(t)
+	switch rv.Kind() {
+	case reflect.String, reflect.Array, reflect.Map, reflect.Slice:
+		return rv.Len() == 0
+	case reflect.Bool:
+		return !rv.Bool()
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return rv.Int() == 0
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		return rv.Uint() == 0
+	case reflect.Float32, reflect.Float64:
+		return rv.Float() == 0
+	case reflect.Invalid:
+		return true
+	case reflect.Interface, reflect.Ptr:
+		if rv.IsNil() {
+			return true
+		}
+		return Empty(rv.Elem().Interface())
+	case reflect.Struct:
+		v, ok := rv.Interface().(time.Time)
+		if ok && v.IsZero() {
+			return true
+		}
+	}
+	return false
+}
+
+func NotEmpty[T any](t T) bool {
+	return !Empty(t)
+}
+
+func URLEncoded(str string) bool {
+	return uRLEncodedRegex.MatchString(str)
+}
+
+func HTMLEncoded(str string) bool {
+	return hTMLEncodedRegex.MatchString(str)
+}
+
+func HTML(str string) bool {
+	return hTMLRegex.MatchString(str)
+}
+
+// File is the validation function for validating if the current field's value is a valid file path.
+func File(val any) bool {
+	field := reflect.ValueOf(val)
+	switch field.Kind() {
+	case reflect.String:
+		fileInfo, err := os.Stat(field.String())
+		if err != nil {
+			return false
+		}
+		return !fileInfo.IsDir()
+	}
+	//fmt.Errorf("bad value type %T", field.Interface())
+	return false
+}
+
+// Dir is the validation function for validating if the current field's value is a valid directory.
+func Dir(val any) bool {
+	field := reflect.ValueOf(val)
+	if field.Kind() == reflect.String {
+		fileInfo, err := os.Stat(field.String())
+		if err != nil {
+			return false
+		}
+		return fileInfo.IsDir()
+	}
+	//fmt.Errorf("bad field type %T", field.Interface())
+	return false
+}
+
+func OneOf(val any, vals []any) bool {
+	//rv := reflect.ValueOf(val)
+	//
+	//var v string
+	//switch rv.Kind() {
+	//case reflect.String:
+	//	v = rv.String()
+	//case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+	//	v = strconv.FormatInt(rv.Int(), 10)
+	//case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+	//	v = strconv.FormatUint(rv.Uint(), 10)
+	//default:
+	//	//fmt.Errorf("Bad rv type %T", rv.Interface())
+	//	return false
+	//}
+	//for i := 0; i < len(vals); i++ {
+	//	if vals[i] == v {
+	//		return true
+	//	}
+	//}
+	if len(vals) == 0 {
+		return false
+	}
+	for _, a := range vals {
+		if Equal(val, a) {
+			return true
+		}
+	}
+	return false
+}
+
+func Length(val any, length int, op string) bool {
+	if n := calcLength(val); n == -1 {
+		return false
+	} else {
+		return Compare(n, length, op)
+	}
+}
+
+func LengthBetween(val any, min, max int) bool {
+	if !Compare(min, max, "<") {
+		panic(ErrBadType)
+	} else if n, err := getLength(val, false); err != nil {
+		return false
+	} else {
+		return Compare(n, min, ">=") && Compare(n, max, "<=")
+	}
+}
+
+// Compare intX,floatX value by given op. returns `srcVal op(=,!=,<,<=,>,>=) dstVal`
+//
+// Usage:
+//
+//	compare(2, 3, ">") // false
+//	compare(2, 1.3, ">") // true
+//	compare(2.2, 1.3, ">") // true
+//	compare(2.1, 2, ">") // true
+func Compare(srcVal, dstVal any, op string) bool {
+	srv := reflect.ValueOf(srcVal)
+
+	switch srv.Kind() {
+	case reflect.Struct:
+		if srv.Type().ConvertibleTo(timeType) {
+			drv := reflect.ValueOf(dstVal)
+			if drv.Type().ConvertibleTo(timeType) {
+				at := srv.Convert(timeType).Interface().(time.Time)
+				bt := drv.Convert(timeType).Interface().(time.Time)
+				return compTime(at, bt, op)
+			}
+		}
+	case reflect.Bool:
+		drv := reflect.ValueOf(dstVal)
+		switch drv.Kind() {
+		case reflect.Bool:
+			return compBool(srv.Bool(), drv.Bool(), op)
+		case reflect.String:
+			if bl, err := strconv.ParseBool(drv.String()); err == nil {
+				return compBool(srv.Bool(), bl, op)
+			}
+		}
+	default:
+		if srcStr, ok := srcVal.(string); ok {
+			if dstStr, ok2 := dstVal.(string); ok2 {
+				return compString(srcStr, dstStr, op)
+			}
+			break
+		}
+
+		// float
+		if srcFlt, ok := srcVal.(float64); ok {
+			if dstFlt, err := toFloat(dstVal); err == nil {
+				return compNum(srcFlt, dstFlt, op)
+			}
+			break
+		}
+
+		if srcFlt, ok := srcVal.(float32); ok {
+			if dstFlt, err := toFloat(dstVal); err == nil {
+				return compNum(float64(srcFlt), dstFlt, op)
+			}
+			break
+		}
+
+		// as int64
+		if srcInt, err := toInt64(srcVal); err != nil {
+			break
+		} else if dstInt, ex := toInt64(dstVal); ex != nil {
+			break
+		} else {
+			return compNum(srcInt, dstInt, op)
+		}
+	}
+
+	switch op {
+	case "=":
+		return srcVal == dstVal
+	case "!=":
+		return srcVal != dstVal
+	default:
+		//ErrBadType
+		return false
+	}
+}
+
+// GreaterThan is the validation function for validating if the current field's value is greater than the param's value.
+func GreaterThan(a, b any) bool {
+	return Compare(a, b, ">")
+}
+
+// GreaterEqualThan is the validation function for validating if the current field's value is greater than or equal to the param's value.
+func GreaterEqualThan(a, b any) bool {
+	return Compare(a, b, ">=")
+}
+
+// LessThan is the validation function for validating if the current field's value is less than the param's value.
+func LessThan(a, b any) bool {
+	return Compare(a, b, "<")
+}
+
+// LessEqualThan is the validation function for validating if the current field's value is less than or equal to the param's value.
+func LessEqualThan(a, b any) bool {
+	return Compare(a, b, "<=")
+}
+
+// Equal is the validation function for validating if the current field's value is equal to the param's value.
+func Equal(a, b any) bool {
+	return Compare(a, b, "=")
+}
+
+func NotEqual(a, b any) bool {
+	return Compare(a, b, "!=")
+}
+
+func Between(val, min, max any) bool {
+	if !Compare(min, max, ">") {
+		panic(ErrBadRange)
+	}
+
+	return Compare(val, min, ">=") && Compare(val, max, "<=")
+}
+
+func NotBetween(val, min, max any) bool {
+	if !Compare(min, max, ">") {
+		panic(ErrBadRange)
+	}
+
+	return Compare(val, min, "<") || Compare(val, max, ">")
+}
diff --git a/pkg/is/regexes.go b/pkg/is/regexes.go
new file mode 100644
index 0000000..1b3eef1
--- /dev/null
+++ b/pkg/is/regexes.go
@@ -0,0 +1,79 @@
+package is
+
+import "regexp"
+
+const (
+	alphaRegexString               = "^[a-zA-Z]+$"
+	alphaNumericRegexString        = "^[a-zA-Z0-9]+$"
+	alphaUnicodeRegexString        = "^[\\p{L}]+$"
+	alphaUnicodeNumericRegexString = "^[\\p{L}\\p{N}]+$"
+	numericRegexString             = "^[-+]?[0-9]+(?:\\.[0-9]+)?$"
+	numberRegexString              = "^[0-9]+$"
+	hexadecimalRegexString         = "^(0[xX])?[0-9a-fA-F]+$"
+	hexColorRegexString            = "^#(?:[0-9a-fA-F]{3}|[0-9a-fA-F]{4}|[0-9a-fA-F]{6}|[0-9a-fA-F]{8})$"
+	rgbRegexString                 = "^rgb\\(\\s*(?:(?:0|[1-9]\\d?|1\\d\\d?|2[0-4]\\d|25[0-5])\\s*,\\s*(?:0|[1-9]\\d?|1\\d\\d?|2[0-4]\\d|25[0-5])\\s*,\\s*(?:0|[1-9]\\d?|1\\d\\d?|2[0-4]\\d|25[0-5])|(?:0|[1-9]\\d?|1\\d\\d?|2[0-4]\\d|25[0-5])%\\s*,\\s*(?:0|[1-9]\\d?|1\\d\\d?|2[0-4]\\d|25[0-5])%\\s*,\\s*(?:0|[1-9]\\d?|1\\d\\d?|2[0-4]\\d|25[0-5])%)\\s*\\)$"
+	rgbaRegexString                = "^rgba\\(\\s*(?:(?:0|[1-9]\\d?|1\\d\\d?|2[0-4]\\d|25[0-5])\\s*,\\s*(?:0|[1-9]\\d?|1\\d\\d?|2[0-4]\\d|25[0-5])\\s*,\\s*(?:0|[1-9]\\d?|1\\d\\d?|2[0-4]\\d|25[0-5])|(?:0|[1-9]\\d?|1\\d\\d?|2[0-4]\\d|25[0-5])%\\s*,\\s*(?:0|[1-9]\\d?|1\\d\\d?|2[0-4]\\d|25[0-5])%\\s*,\\s*(?:0|[1-9]\\d?|1\\d\\d?|2[0-4]\\d|25[0-5])%)\\s*,\\s*(?:(?:0.[1-9]*)|[01])\\s*\\)$"
+	hslRegexString                 = "^hsl\\(\\s*(?:0|[1-9]\\d?|[12]\\d\\d|3[0-5]\\d|360)\\s*,\\s*(?:(?:0|[1-9]\\d?|100)%)\\s*,\\s*(?:(?:0|[1-9]\\d?|100)%)\\s*\\)$"
+	hslaRegexString                = "^hsla\\(\\s*(?:0|[1-9]\\d?|[12]\\d\\d|3[0-5]\\d|360)\\s*,\\s*(?:(?:0|[1-9]\\d?|100)%)\\s*,\\s*(?:(?:0|[1-9]\\d?|100)%)\\s*,\\s*(?:(?:0.[1-9]*)|[01])\\s*\\)$"
+	emailRegexString               = "^(?:(?:(?:(?:[a-zA-Z]|\\d|[!#\\$%&'\\*\\+\\-\\/=\\?\\^_`{\\|}~]|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])+(?:\\.([a-zA-Z]|\\d|[!#\\$%&'\\*\\+\\-\\/=\\?\\^_`{\\|}~]|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])+)*)|(?:(?:\\x22)(?:(?:(?:(?:\\x20|\\x09)*(?:\\x0d\\x0a))?(?:\\x20|\\x09)+)?(?:(?:[\\x01-\\x08\\x0b\\x0c\\x0e-\\x1f\\x7f]|\\x21|[\\x23-\\x5b]|[\\x5d-\\x7e]|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])|(?:(?:[\\x01-\\x09\\x0b\\x0c\\x0d-\\x7f]|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}]))))*(?:(?:(?:\\x20|\\x09)*(?:\\x0d\\x0a))?(\\x20|\\x09)+)?(?:\\x22))))@(?:(?:(?:[a-zA-Z]|\\d|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])|(?:(?:[a-zA-Z]|\\d|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])(?:[a-zA-Z]|\\d|-|\\.|~|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])*(?:[a-zA-Z]|\\d|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])))\\.)+(?:(?:[a-zA-Z]|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])|(?:(?:[a-zA-Z]|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])(?:[a-zA-Z]|\\d|-|\\.|~|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])*(?:[a-zA-Z]|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])))\\.?$"
+	e164RegexString                = "^\\+[1-9]?[0-9]{7,14}$"
+	phoneNumberRegexString         = "^(\\+?86)?1[0-9]{10}$"
+	base64RegexString              = "^(?:[A-Za-z0-9+\\/]{4})*(?:[A-Za-z0-9+\\/]{2}==|[A-Za-z0-9+\\/]{3}=|[A-Za-z0-9+\\/]{4})$"
+	base64URLRegexString           = "^(?:[A-Za-z0-9-_]{4})*(?:[A-Za-z0-9-_]{2}==|[A-Za-z0-9-_]{3}=|[A-Za-z0-9-_]{4})$"
+	uUID3RegexString               = "^[0-9a-f]{8}-[0-9a-f]{4}-3[0-9a-f]{3}-[0-9a-f]{4}-[0-9a-f]{12}$"
+	uUID4RegexString               = "^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$"
+	uUID5RegexString               = "^[0-9a-f]{8}-[0-9a-f]{4}-5[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$"
+	uUIDRegexString                = "^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$"
+	uLIDRegexString                = "^[A-HJKMNP-TV-Z0-9]{26}$"
+	md4RegexString                 = "^[0-9a-f]{32}$"
+	md5RegexString                 = "^[0-9a-f]{32}$"
+	sha256RegexString              = "^[0-9a-f]{64}$"
+	sha384RegexString              = "^[0-9a-f]{96}$"
+	sha512RegexString              = "^[0-9a-f]{128}$"
+	aSCIIRegexString               = "^[\x00-\x7F]*$"
+	latitudeRegexString            = "^[-+]?([1-8]?\\d(\\.\\d+)?|90(\\.0+)?)$"
+	longitudeRegexString           = "^[-+]?(180(\\.0+)?|((1[0-7]\\d)|([1-9]?\\d))(\\.\\d+)?)$"
+	uRLEncodedRegexString          = `^(?:[^%]|%[0-9A-Fa-f]{2})*$`
+	hTMLEncodedRegexString         = `&#[x]?([0-9a-fA-F]{2})|(&gt)|(&lt)|(&quot)|(&amp)+[;]?`
+	hTMLRegexString                = `<[/]?([a-zA-Z]+).*?>`
+	jWTRegexString                 = "^[A-Za-z0-9-_]+\\.[A-Za-z0-9-_]+\\.[A-Za-z0-9-_]*$"
+	semverRegexString              = `^(0|[1-9]\d*)\.(0|[1-9]\d*)\.(0|[1-9]\d*)(?:-((?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*)(?:\.(?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*))*))?(?:\+([0-9a-zA-Z-]+(?:\.[0-9a-zA-Z-]+)*))?$` // numbered capture groups https://semver.org/
+)
+
+var (
+	alphaRegex               = regexp.MustCompile(alphaRegexString)
+	alphaNumericRegex        = regexp.MustCompile(alphaNumericRegexString)
+	alphaUnicodeRegex        = regexp.MustCompile(alphaUnicodeRegexString)
+	alphaUnicodeNumericRegex = regexp.MustCompile(alphaUnicodeNumericRegexString)
+	numericRegex             = regexp.MustCompile(numericRegexString)
+	numberRegex              = regexp.MustCompile(numberRegexString)
+	hexadecimalRegex         = regexp.MustCompile(hexadecimalRegexString)
+	hexColorRegex            = regexp.MustCompile(hexColorRegexString)
+	rgbRegex                 = regexp.MustCompile(rgbRegexString)
+	rgbaRegex                = regexp.MustCompile(rgbaRegexString)
+	hslRegex                 = regexp.MustCompile(hslRegexString)
+	hslaRegex                = regexp.MustCompile(hslaRegexString)
+	e164Regex                = regexp.MustCompile(e164RegexString)
+	phoneNumberRegex         = regexp.MustCompile(phoneNumberRegexString)
+	emailRegex               = regexp.MustCompile(emailRegexString)
+	base64Regex              = regexp.MustCompile(base64RegexString)
+	base64URLRegex           = regexp.MustCompile(base64URLRegexString)
+	uUID3Regex               = regexp.MustCompile(uUID3RegexString)
+	uUID4Regex               = regexp.MustCompile(uUID4RegexString)
+	uUID5Regex               = regexp.MustCompile(uUID5RegexString)
+	uUIDRegex                = regexp.MustCompile(uUIDRegexString)
+	uLIDRegex                = regexp.MustCompile(uLIDRegexString)
+	md4Regex                 = regexp.MustCompile(md4RegexString)
+	md5Regex                 = regexp.MustCompile(md5RegexString)
+	sha256Regex              = regexp.MustCompile(sha256RegexString)
+	sha384Regex              = regexp.MustCompile(sha384RegexString)
+	sha512Regex              = regexp.MustCompile(sha512RegexString)
+	aSCIIRegex               = regexp.MustCompile(aSCIIRegexString)
+	latitudeRegex            = regexp.MustCompile(latitudeRegexString)
+	longitudeRegex           = regexp.MustCompile(longitudeRegexString)
+	uRLEncodedRegex          = regexp.MustCompile(uRLEncodedRegexString)
+	hTMLEncodedRegex         = regexp.MustCompile(hTMLEncodedRegexString)
+	hTMLRegex                = regexp.MustCompile(hTMLRegexString)
+	jWTRegex                 = regexp.MustCompile(jWTRegexString)
+	semverRegex              = regexp.MustCompile(semverRegexString)
+)
diff --git a/pkg/is/util.go b/pkg/is/util.go
new file mode 100644
index 0000000..3d180e8
--- /dev/null
+++ b/pkg/is/util.go
@@ -0,0 +1,211 @@
+package is
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"reflect"
+	"strconv"
+	"strings"
+	"time"
+	"unicode/utf8"
+)
+
+var (
+	ErrBadType  = errors.New("bad value type")
+	ErrBadRange = errors.New("bad value range")
+
+	timeType = reflect.TypeOf(time.Time{})
+	//nilType  = reflect.TypeOf([]byte(nil))
+)
+
+// convert value to float64, return error on failed
+func toFloat(in any) (f64 float64, err error) {
+	switch tVal := in.(type) {
+	case nil:
+		f64 = 0
+	case string:
+		f64, err = strconv.ParseFloat(strings.TrimSpace(tVal), 64)
+	case int:
+		f64 = float64(tVal)
+	case int8:
+		f64 = float64(tVal)
+	case int16:
+		f64 = float64(tVal)
+	case int32:
+		f64 = float64(tVal)
+	case int64:
+		f64 = float64(tVal)
+	case uint:
+		f64 = float64(tVal)
+	case uint8:
+		f64 = float64(tVal)
+	case uint16:
+		f64 = float64(tVal)
+	case uint32:
+		f64 = float64(tVal)
+	case uint64:
+		f64 = float64(tVal)
+	case float32:
+		f64 = float64(tVal)
+	case float64:
+		f64 = tVal
+	case time.Duration:
+		f64 = float64(tVal)
+	case json.Number:
+		f64, err = tVal.Float64()
+	default:
+		err = ErrBadType
+	}
+	return
+}
+
+// convert string to int64, return error on failed
+func toInt64(in any) (i64 int64, err error) {
+	switch tVal := in.(type) {
+	case nil:
+		i64 = 0
+	case string:
+		i64, err = strconv.ParseInt(strings.TrimSpace(tVal), 10, 0)
+	case int:
+		i64 = int64(tVal)
+	case int8:
+		i64 = int64(tVal)
+	case int16:
+		i64 = int64(tVal)
+	case int32:
+		i64 = int64(tVal)
+	case int64:
+		i64 = tVal
+	case uint:
+		i64 = int64(tVal)
+	case uint8:
+		i64 = int64(tVal)
+	case uint16:
+		i64 = int64(tVal)
+	case uint32:
+		i64 = int64(tVal)
+	case uint64:
+		i64 = int64(tVal)
+	case float32:
+		i64 = int64(tVal)
+	case float64:
+		i64 = int64(tVal)
+	case time.Duration:
+		i64 = int64(tVal)
+	case json.Number:
+		i64, err = tVal.Int64()
+	default:
+		err = ErrBadType
+	}
+	return
+}
+
+// compString compare string, returns the first op second
+func compString(first, second, op string) bool {
+	rs := strings.Compare(first, second)
+	if rs < 0 {
+		return op == "<" || op == "<="
+	} else if rs > 0 {
+		return op == ">" || op == ">="
+	} else {
+		return op == ">=" || op == "<=" || op == "="
+	}
+}
+
+func compTime(first, dstTime time.Time, op string) (ok bool) {
+	switch op {
+	case "<":
+		return first.Before(dstTime)
+	case "<=":
+		return first.Before(dstTime) || first.Equal(dstTime)
+	case ">":
+		return first.After(dstTime)
+	case ">=":
+		return first.After(dstTime) || first.Equal(dstTime)
+	case "=":
+		return first.Equal(dstTime)
+	case "!=":
+		return !first.Equal(dstTime)
+	}
+	return
+}
+
+func compNum[T int64 | float64 | uint64](first, second T, op string) bool {
+	switch op {
+	case "<":
+		return first < second
+	case "<=":
+		return first <= second
+	case ">":
+		return first > second
+	case ">=":
+		return first >= second
+	case "=":
+		return first == second
+	case "!=":
+		return first != second
+	}
+	return false
+}
+
+func compBool(first, second bool, op string) bool {
+	return compNum(boo2int(first), boo2int(second), op)
+}
+
+func boo2int(a bool) int64 {
+	if a {
+		return 1
+	} else {
+		return 0
+	}
+}
+
+// get reflect value length
+func calcLength(val any) int {
+	v := reflect.Indirect(reflect.ValueOf(val))
+
+	// (u)int use width.
+	switch v.Kind() {
+	case reflect.String:
+		return len([]rune(v.String()))
+	case reflect.Map, reflect.Array, reflect.Chan, reflect.Slice:
+		return v.Len()
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		return len(strconv.FormatInt(int64(v.Uint()), 10))
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return len(strconv.FormatInt(v.Int(), 10))
+	case reflect.Float32, reflect.Float64:
+		return len(fmt.Sprint(v.Interface()))
+	}
+
+	// cannot get length
+	return -1
+}
+
+func getLength(a any, rune bool) (int, error) {
+	field := reflect.ValueOf(a)
+
+	//if !field.IsValid() || field.IsNil() {
+	//	return 0, nil
+	//}
+
+	switch field.Kind() {
+	case reflect.String:
+		if rune {
+			return utf8.RuneCountInString(field.String()), nil
+		}
+		return field.Len(), nil
+
+	case reflect.Slice, reflect.Map, reflect.Array:
+		return field.Len(), nil
+
+	case reflect.Ptr:
+		if field.Type().Elem().Kind() == reflect.Array {
+			// 类型声明中的长度
+			return field.Type().Elem().Len(), nil
+		}
+	}
+
+	return 0, ErrBadType
+}