cc_mastercard man page

valtype::creditcard::mastercard — Validation for Mastercard creditcard number


package require Tcl  8.5

package require snit  2

package require valtype::common

package require valtype::luhn

package require valtype::creditcard::mastercard  ?1?

valtype::creditcard::mastercard validate value

valtype::creditcard::mastercard checkdigit value


This package implements a snit validation type for a Mastercard creditcard number.

A validation type is an object that can be used to validate Tcl values of a particular kind.  For example, snit::integer, a validation type defined by the snit package is used to validate that a Tcl value is an integer.

Every validation type has a validate method which is used to do the validation. This method must take a single argument, the value to be validated; further, it must do nothing if the value is valid, but throw an error if the value is invalid:

    valtype::creditcard::mastercard validate .... ;# Does nothing
    valtype::creditcard::mastercard validate .... ;# Throws an error (bad Mastercard creditcard number).

The validate method will always return the validated value on success, and throw the -errorcode INVALID on error, possibly with additional elements which provide more details about the problem.


The API provided by this package satisfies the specification of snit validation types found in the documentation of Snit's Not Incr Tcl.

valtype::creditcard::mastercard validate value

This method validates the value and returns it, possibly in a canonical form, if it passes. If the value does not pass the validation an error is thrown.

valtype::creditcard::mastercard checkdigit value

This method computes a check digit for the value. Before doing so it is validated, except for a checkdigit. If the value does not pass the validation no check digit is calculated and an error is thrown instead.

Error Codes

As said in the package description, the errors thrown by the commands of this package in response to input validation failures use the -errorcode INVALID to distinguish themselves from package internal errors.

To provide more detailed information about why the validation failed the -errorCode goes actually beyond that. First, it will contain a code detailing the type itself. Here this is CREDITCARD MASTERCARD. This is then followed by values detailing the reason for the failure. The full set of -errorCodes which can be thrown by this package are:


The input value contained one or more bad characters, i.e. characters which must not occur in the input for it to be a Mastercard creditcard number.


The check digit of the input value is wrong. This usually signals a data-entry error, with digits transposed, forgotten, etc. Of course, th input may be an outright fake too.


The input value is of the wrong length to be a Mastercard creditcard number.


The input value does not start with the magic value(s) required for it to be a Mastercard creditcard number.

Bugs, Ideas, Feedback

This document, and the package it describes, will undoubtedly contain bugs and other problems. Please report such in the category valtype of the Tcllib Trackers []. Please also report any ideas for enhancements you may have for either package and/or documentation.


Checking, MasterCard, Testing, Type checking, Validation, Value checking, bank, card for credit, credit card, finance, isA


Validation, Type checking


1 tcllib Validation types