func IsDataURI(str string) bool {
	dataURI := strings.Split(str, ",")
	if !rxDataURI.MatchString(dataURI[0]) {
		return false
	}
	return IsBase64(dataURI[1])
}
IsDataURI checks if a string is base64 encoded data URI such as an image
package godash
import (
	"encoding/base64"
	"encoding/json"
	"math"
	"net"
	"net/url"
	"regexp"
	"strconv"
	"strings"
	"unicode"
	"unicode/utf8"
)
func IsInRange(value, left, right float64) bool {
	if left > right {
		left, right = right, left
	}
	return value >= left && value <= right
}
func IsEmail(s string) bool {
	if !strings.Contains(s, "@") || string(s[0]) == "@" || string(s[len(s)-1]) == "@" {
		return false
	}
	return true
}
func IsURL(str string) bool {
	if str == "" || len(str) >= 2083 || len(str) <= 3 || strings.HasPrefix(str, ".") {
		return false
	}
	u, err := url.Parse(str)
	if err != nil {
		return false
	}
	if strings.HasPrefix(u.Host, ".") {
		return false
	}
	if u.Host == "" && (u.Path != "" && !strings.Contains(u.Path, ".")) {
		return false
	}
	return rxURL.MatchString(str)
}
func IsRequestURL(rawurl string) bool {
	url, err := url.ParseRequestURI(rawurl)
	if err != nil {
		return false  
	}
	if len(url.Scheme) == 0 {
		return false  
	}
	return true
}
func IsRequestURI(rawurl string) bool {
	_, err := url.ParseRequestURI(rawurl)
	return err == nil
}
func IsAlpha(s string) bool {
	for _, v := range s {
		if ('Z' < v || v < 'A') && ('z' < v || v < 'a') {
			return false
		}
	}
	return true
}
func IsUTFLetter(str string) bool {
	for _, v := range str {
		if !unicode.IsLetter(v) {
			return false
		}
	}
	return true
}
func IsAlphanumeric(s string) bool {
	for _, v := range s {
		if ('Z' < v || v < 'A') && ('z' < v || v < 'a') && ('9' < v || v < '0') {
			return false
		}
	}
	return true
}
func IsUTFLetterNumeric(s string) bool {
	for _, v := range s {
		if !unicode.IsLetter(v) && !unicode.IsNumber(v) {  
			return false
		}
	}
	return true
}
func IsNumeric(s string) bool {
	for _, v := range s {
		if '9' < v || v < '0' {
			return false
		}
	}
	return true
}
func IsUTFNumeric(s string) bool {
	for _, v := range s {
		if unicode.IsNumber(v) == false {
			return false
		}
	}
	return true
}
func IsNegative(value float64) bool {
	return value < 0
}
func IsPositive(value float64) bool {
	return value > 0
}
func IsNonNegative(value float64) bool {
	return value >= 0
}
func IsNonPositive(value float64) bool {
	return value <= 0
}
func IsWhole(value float64) bool {
	return math.Abs(math.Remainder(value, 1)) == 0
}
func IsNatural(value float64) bool {
	return IsWhole(value) && IsPositive(value)
}
func IsUTFDigit(s string) bool {
	for _, v := range s {
		if !unicode.IsDigit(v) {
			return false
		}
	}
	return true
}
func IsHexadecimal(str string) bool {
	return rxHexadecimal.MatchString(str)
}
func IsHexcolor(str string) bool {
	return rxHexcolor.MatchString(str)
}
func IsRGBcolor(str string) bool {
	return rxRGBcolor.MatchString(str)
}
func IsLowerCase(str string) bool {
	if IsNull(str) {
		return true
	}
	return str == strings.ToLower(str)
}
func IsUpperCase(str string) bool {
	if IsNull(str) {
		return true
	}
	return str == strings.ToUpper(str)
}
func IsInt(str string) bool {
	if IsNull(str) {
		return true
	}
	return rxInt.MatchString(str)
}
func IsFloat(str string) bool {
	return str != "" && rxFloat.MatchString(str)
}
func IsDivisibleBy(str, num string) bool {
	f, _ := ToFloat(str)
	p := int64(f)
	q, _ := ToInt(num)
	if q == 0 {
		return false
	}
	return (p == 0) || (p%q == 0)
}
func IsNull(str string) bool {
	return len(str) == 0
}
func IsByteLength(str string, min, max int) bool {
	return len(str) >= min && len(str) <= max
}
func IsUUIDv3(str string) bool {
	return rxUUID3.MatchString(str)
}
func IsUUIDv4(str string) bool {
	return rxUUID4.MatchString(str)
}
func IsUUIDv5(str string) bool {
	return rxUUID5.MatchString(str)
}
func IsUUID(str string) bool {
	return rxUUID.MatchString(str)
}
func IsCreditCard(str string) bool {
	r, _ := regexp.Compile("[^0-9]+")
	sanitized := r.ReplaceAll([]byte(str), []byte(""))
	if !rxCreditCard.MatchString(string(sanitized)) {
		return false
	}
	var sum int64
	var digit string
	var tmpNum int64
	var shouldDouble bool
	for i := len(sanitized) - 1; i >= 0; i-- {
		digit = string(sanitized[i:(i + 1)])
		tmpNum, _ = ToInt(digit)
		if shouldDouble {
			tmpNum *= 2
			if tmpNum >= 10 {
				sum += ((tmpNum % 10) + 1)
			} else {
				sum += tmpNum
			}
		} else {
			sum += tmpNum
		}
		shouldDouble = !shouldDouble
	}
	if sum%10 == 0 {
		return true
	}
	return false
}
func IsISBN10(str string) bool {
	return IsISBN(str, 10)
}
func IsISBN13(str string) bool {
	return IsISBN(str, 13)
}
func IsISBN(str string, version int) bool {
	r, _ := regexp.Compile("[\\s-]+")
	sanitized := r.ReplaceAll([]byte(str), []byte(""))
	var checksum int32
	var i int32
	if version == 10 {
		if !rxISBN10.MatchString(string(sanitized)) {
			return false
		}
		for i = 0; i < 9; i++ {
			checksum += (i + 1) * int32(sanitized[i]-'0')
		}
		if sanitized[9] == 'X' {
			checksum += 10 * 10
		} else {
			checksum += 10 * int32(sanitized[9]-'0')
		}
		if checksum%11 == 0 {
			return true
		}
		return false
	} else if version == 13 {
		if !rxISBN13.MatchString(string(sanitized)) {
			return false
		}
		factor := []int32{1, 3}
		for i = 0; i < 12; i++ {
			checksum += factor[i%2] * int32(sanitized[i]-'0')
		}
		if (int32(sanitized[12]-'0'))-((10-(checksum%10))%10) == 0 {
			return true
		}
		return false
	}
	return IsISBN(str, 10) || IsISBN(str, 13)
}
func IsJSON(str string) bool {
	var js json.RawMessage
	return json.Unmarshal([]byte(str), &js) == nil
}
func IsMultibyte(s string) bool {
	for _, v := range s {
		if v >= utf8.RuneSelf {
			return true
		}
	}
	return IsNull(s)
}
func IsASCII(s string) bool {
	for _, v := range s {
		if v >= utf8.RuneSelf {
			return false
		}
	}
	return true
}
func IsPrintableASCII(s string) bool {
	for _, v := range s {
		if v < ' ' || v > '~' {
			return false
		}
	}
	return true
}
func IsFullWidth(str string) bool {
	if IsNull(str) {
		return true
	}
	return rxFullWidth.MatchString(str)
}
func IsHalfWidth(str string) bool {
	if IsNull(str) {
		return true
	}
	return rxHalfWidth.MatchString(str)
}
func IsVariableWidth(str string) bool {
	if IsNull(str) {
		return true
	}
	return rxHalfWidth.MatchString(str) && rxFullWidth.MatchString(str)
}
func IsBase64(s string) bool {
	if IsNull(s) {
		return false
	}
	_, err := base64.StdEncoding.DecodeString(s)
	return err == nil
}
func IsFilePath(str string) (bool, int) {
	if rxWinPath.MatchString(str) {
		if len(str[3:]) > 32767 {
			return false, Win
		}
		return true, Win
	} else if rxUnixPath.MatchString(str) {
		return true, Unix
	}
	return false, Unknown
}