1valtype::luhn5(n)              Validation types              valtype::luhn5(n)
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NAME

8       valtype::luhn5 - Validation for plain number with a LUHN5 checkdigit
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SYNOPSIS

11       package require Tcl  8.5
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13       package require snit  2
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15       package require valtype::common
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17       package require valtype::luhn5  ?1?
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19       valtype::luhn5 validate value
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21       valtype::luhn5 checkdigit value
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DESCRIPTION

26       This  package implements a snit validation type for a plain number with
27       a LUHN5 checkdigit.
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29       A validation type is an object that can be used to validate Tcl  values
30       of  a  particular  kind.  For example, snit::integer, a validation type
31       defined by the snit package is used to validate that a Tcl value is  an
32       integer.
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34       Every  validation  type  has  a validate method which is used to do the
35       validation. This method must take a single argument, the  value  to  be
36       validated; further, it must do nothing if the value is valid, but throw
37       an error if the value is invalid:
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40                  valtype::luhn5 validate .... ;# Does nothing
41                  valtype::luhn5 validate .... ;# Throws an error (bad luhn5 checkdigit).
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44       The validate method will always return the validated value on  success,
45       and throw the -errorcode INVALID on error, possibly with additional el‐
46       ements which provide more details about the problem.
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API

49       The API provided by this package satisfies the  specification  of  snit
50       validation types found in the documentation of Snit's Not Incr Tcl.
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52       valtype::luhn5 validate value
53              This  method  validates  the value and returns it, possibly in a
54              canonical form, if it passes. If the value  does  not  pass  the
55              validation an error is thrown.
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57       valtype::luhn5 checkdigit value
58              This  method  computes a check digit for the value. Before doing
59              so it is validated, except for a checkdigit. If the  value  does
60              not  pass the validation no check digit is calculated and an er‐
61              ror is thrown instead.
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ERROR CODES

64       As said in the package description, the errors thrown by  the  commands
65       of  this  package in response to input validation failures use the -er‐
66       rorcode INVALID to distinguish themselves from package internal errors.
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68       To provide more detailed information about why  the  validation  failed
69       the  -errorCode  goes  actually  beyond that.  First, it will contain a
70       code detailing the type itself. Here this is LUHN5. This is  then  fol‐
71       lowed  by  values detailing the reason for the failure. The full set of
72       -errorCodes which can be thrown by this package are:
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74       INVALID LUHN5 CHARACTER
75              The input value contained one or more bad characters, i.e. char‐
76              acters  which  must  not occur in the input for it to be a plain
77              number with a LUHN5 checkdigit.
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79       INVALID LUHN5 CHECK-DIGIT
80              The check digit of the input value is wrong. This  usually  sig‐
81              nals a data-entry error, with digits transposed, forgotten, etc.
82              Of course, th input may be an outright fake too.
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BUGS, IDEAS, FEEDBACK

85       This document, and the package it describes, will  undoubtedly  contain
86       bugs and other problems.  Please report such in the category valtype of
87       the  Tcllib  Trackers  [http://core.tcl.tk/tcllib/reportlist].   Please
88       also  report any ideas for enhancements you may have for either package
89       and/or documentation.
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91       When proposing code changes, please provide unified diffs, i.e the out‐
92       put of diff -u.
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94       Note  further  that  attachments  are  strongly  preferred over inlined
95       patches. Attachments can be made by going  to  the  Edit  form  of  the
96       ticket  immediately  after  its  creation, and then using the left-most
97       button in the secondary navigation bar.
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KEYWORDS

100       Checking, Testing, Type  checking,  Validation,  Value  checking,  isA,
101       luhn, luhn-5
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CATEGORY

104       Validation, Type checking
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107       Copyright (c) 2011 Andreas Kupries <andreas_kupries@users.sourceforge.net>
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112tcllib                                 1                     valtype::luhn5(n)
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