iso7064

ISO7064 implementation to compute and verify check digits (+ IBAN is implemented too)

Installation

To install iso7064 you need to, as usual, run this command:

go get github.com/pkosilo/iso7064

How to use?

First of all you need to create a new Calculator to compute and verify ISO7064 check digits. BaseCalculator and IBANCalculator are interfaces of Calculator, they implement methods like Verify(input string) (bool, error), Compute(input string) (string, error) and ComputeChars(input string) (string, error). So, you just need to create their instances using one of the methods below

IBAN

To create IBAN compatible Calculator you need to do something like this:

calc := iso7064.NewIBANCalculator()

It will create an instance of IBANCalculator which will have BaseCalculator to compute check digits according to ISO7064 MOD97-10, but also will automatically rearrange input string, replace letters with digits and etc. Remember, that you need to add a placeholder for check digits when you compute with IBANCalculator, it can be any digit-only placeholder (preferred one is 00)

MOD11-2

To create ISO7064 MOD11-2 compatible Calculator you need to do:

calc := iso7064.NewMod112Calculator()

It will return BaseCalculator instance with Modulus equal to 11, Radix equal to 2, Charset equal to 0123456789X and IsDouble equal to false.

MOD37-2

To create ISO7064 MOD37-2 compatible Calculator you need to do:

calc := iso7064.NewMod372Calculator()

It will return BaseCalculator instance with Modulus equal to 37, Radix equal to 2, Charset equal to 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ* and IsDouble equal to false.

MOD97-10

To create ISO7064 MOD97-10 compatible Calculator you need to do:

calc := iso7064.NewMod9710Calculator()

It will return BaseCalculator instance with Modulus equal to 97, Radix equal to 10, Charset equal to 0123456789 and IsDouble equal to true.

MOD661-26

To create ISO7064 MOD661-26 compatible Calculator you need to do:

calc := iso7064.NewMod66126Calculator()

It will return BaseCalculator instance with Modulus equal to 661, Radix equal to 26, Charset equal to ABCDEFGHIJKLMNOPQRSTUVWXYZ and IsDouble equal to true.

MOD1271-36

To create ISO7064 MOD1271-36 compatible Calculator you need to do:

calc := iso7064.NewMod127136Calculator()

It will return BaseCalculator instance with Modulus equal to 1271, Radix equal to 36, Charset equal to 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ and IsDouble equal to true.

BaseCalculator

As you may spot in examples before, functions NewMod****Calculator always return BaseCalculator with different Modulus, Radix, Charset and IsDouble. So, it means that BaseController can take any Modulus, Radix, Charset and IsDouble, and you can create your own custom BaseCalculator:

calc := &iso7064.BaseCalculator {
  Modulus:  97,
  Radix:    10,
  Charset:  "0123456789",
  IsDouble: true,
}

Compute and verify

Verify(input string) (bool, error)

To verify existing string that it has correct check digits, you need to do:

input := "1234123435"

calc := iso7064.NewMod9710Calculator()
correct, err := calc.Verify(input)
fmt.Println(correct, err) // Will return `true <nil>`

In case of an error it will return false and error itself. Error may happen if the input is too short (shorter or equal to check digits length), the input has InvalidRune, which is not present in the Charset.

Compute(input string) (string, error)

This function will return input string the check digits added to it. If it is BaseCalculator, check digits will be located at the end of the string. It it is IBANCalculator, they will be located at position 2-3 (couting from zero, remember) in the output string. Remember, you need to add a placeholder for check digits if you use IBANCalculator (again preferred one is 00).

input := "12341234"

calc := iso7064.NewMod9710Calculator()
computed, err := calc.Compute(input)
fmt.Println(computed, err) // Will return `1234123435 <nil>`

ComputeChars(input string) (string, error)

input := "12341234"

calc := iso7064.NewMod9710Calculator()
computedChars, err := calc.ComputeChars(input)
fmt.Println(computedChars, err) // Will return `35 <nil>`

pkasila / iso7064