README.md

is

The is package provides a comprehensive set of validation functions for various data types commonly used in web applications, financial systems, and general software development. It offers a clean, efficient way to validate data formats ranging from basic types to complex financial and network identifiers.

Features

Account & Identity Validation

• Email(string) bool - Email addresses
• Nickname(string, ...bool) bool - Usernames (with optional strict mode)
• VariableName(string, ...bool) bool - Programming variable names
• VariableNameFor(string, string) (bool, error) - Language-specific variable names

Financial Validation

• BankCard(string, ...*regexp.Regexp) bool - Credit/Debit card numbers with optional card type checking
• IBAN(string, ...bool) bool - International Bank Account Numbers
• Iban(string, ...bool) bool - Alias for IBAN validation

Geographic Validation

• Latitude[T string|float64](T) bool - Latitude coordinates
• Longitude[T string|float64](T) bool - Longitude coordinates
• Coordinates[T string|float64](lat, lon T) bool - Coordinate pairs

Network & Communication

• IPv4(string) bool - IPv4 addresses
• IPv6(string) bool - IPv6 addresses
• IP(string) bool - Any IP address (v4 or v6)
• Phone(string) bool - Phone numbers
• E164(string) bool - E.164 format phone numbers

String Type Validation

• Alpha(string) bool - Alphabetic characters
• Alnum(string) bool - Alphanumeric characters
• Digit(string) bool - Numeric digits only
• Lower(string) bool - Lowercase letters
• Upper(string) bool - Uppercase letters
• Title(string) bool - Title case text
• Space(string) bool - Whitespace characters
• Numeric(string) bool - Numeric strings (including decimals)
• Decimal(string) bool - Decimal numbers
• Float(string) bool - Floating-point numbers

Number Type Validation

• Even[T Numerable](T, ...bool) bool - Even numbers
• Odd[T Numerable](T, ...bool) bool - Odd numbers
• Whole[T Numerable](T) bool - Whole numbers
• Natural[T Numerable](T) bool - Natural numbers
• Positive[T Numerable](T) bool - Positive numbers
• Negative[T Numerable](T) bool - Negative numbers
• Zero[T Numerable](T) bool - Zero value check

Encoding & Format Validation

• Base64(string) bool - Base64 encoding
• Base64URL(string) bool - URL-safe Base64 encoding
• Hex(string) bool - Hexadecimal strings
• Bin(string) bool - Binary strings
• HexColor(string) bool - Hexadecimal color codes
• RGBColor(string) bool - RGB color format
• MD5(string) bool - MD5 hash strings
• JWT(string) bool - JSON Web Tokens

Mobile & Telecom

• IMEI[T string|int64](T) bool - International Mobile Equipment Identity
• IMSI(string) bool - International Mobile Subscriber Identity

Installation

go get -u github.com/goloop/is

Important Note

The package provides validation functions that do not pre-clean the data. If the validation data needs to be cleaned, it must be cleaned beforehand, for example, using the g package.

Example:

raw := "GB82 WEST 1234 5698 7654 32"    // contains spaces
iban := g.Weed(raw, g.Whitespaces)      // remove spaces
valid := is.IBAN(iban)                  // validate

Usage Examples

Basic Validation

package main

import (
    "fmt"
    "github.com/goloop/is"
)

func main() {
    // Email validation.
    fmt.Println(is.Email("[email protected]"))         // true
    fmt.Println(is.Email("invalid-email"))            // false

    // Phone number validation.
    fmt.Println(is.Phone("+1 (234) 567-8900"))        // true
    fmt.Println(is.E164("+12345678900"))              // true

    // Geographic coordinates.
    fmt.Println(is.Coordinates(51.5074, -0.1278))     // true
    fmt.Println(is.Coordinates(91.0, 0.0))            // false

    // Financial validation.
    fmt.Println(is.BankCard("4111111111111111"))      // true
    fmt.Println(is.IBAN("DE89370400440532013000"))    // true
}

Advanced Validation

package main

import (
    "fmt"
    "github.com/goloop/is"
)

func main() {
    // Variable name validation for different languages.
    fmt.Println(is.VariableNameFor("myVar", "go"))     // true
    fmt.Println(is.VariableNameFor("class", "python")) // false (reserved word)

    // Strict mode validation.
    fmt.Println(is.Nickname("user123", true))          // true
    fmt.Println(is.Nickname("user@123", true))         // false

    // Number validation.
    fmt.Println(is.Even(4))                            // true
    fmt.Println(is.Natural(5))                         // true
    fmt.Println(is.Positive(-1))                       // false

    // Format validation.
    fmt.Println(is.HexColor("#FF5733"))                // true
    fmt.Println(is.Base64("SGVsbG8="))                 // true
    fmt.Println(is.JWT("eyJhbGciOiJIUzI..."))          // true
}

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

This project is licensed under the MIT License - see the LICENSE file for details.