valtype::isbn(3tcl)

✨ valtype::isbn ✨

okay bestie, welcome to the valtype::isbn(3tcl) page 💖 this is the validation-type manual from the tcllib crew, and it's literally all about making sure your ISBN is not a mess. buckle up 🎀

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🌸 SYNOPSIS 🌸

package require Tcl 8.5 9

package require snit 2

package require valtype::common

package require valtype::isbn ?1.1?

valtype::isbn validate value

valtype::isbn checkdigit value

valtype::isbn 13of value

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💅 NAME 💅

valtype::isbn — Validation for ISBN. that's it, that's the whole job description 🫶

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🦋 DESCRIPTION 🦋

So. This package implements a snit validation type for an ISBN. that's the vibe 💖

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. same energy, different flavor ✨

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::isbn validate .... ;# Does nothing
valtype::isbn validate .... ;# Throws an error (bad ISBN).

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. iykyk 😭

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👑 API 👑

The API provided by this package satisfies the specification of snit validation types found in the documentation of Snit's Not Incr Tcl. slay, standards-compliant 💅

• valtype::isbn 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. no notes, iconic behavior ✨
• valtype::isbn 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. it's giving "no shortcut, we check first" 🔥
• valtype::isbn 13of value — This method expects an old-style 10-digit ISBN and returns the canonical modern 13-digit ISBN. This is used by validate to canonicalize the input, so that all parts of the system after the validation can expect to work with modern 13-digit ISBNs. glow-up arc for your old ISBNs fr fr 🌈

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💀 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. that's the little tag that says "this is a you problem, not a us problem" 🙈

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 ISBN. 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:

• INVALID ISBN CHARACTER — The input value contained one or more bad characters, i.e. characters which must not occur in the input for it to be an ISBN. bestie what is that letter doing in there 😭
• INVALID ISBN CHECK-DIGIT — 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. (yes, "th input" — that's what it says, and we do not touch the sacred text 💀)
• INVALID ISBN LENGTH — The input value is of the wrong length to be an ISBN. too short, too long, just not it 🫶

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🧚 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 [http://core.tcl.tk/tcllib/reportlist](http://core.tcl.tk/tcllib/reportlist). Please also report any ideas for enhancements you may have for either package and/or documentation. we want the tea, we want the receipts 💜

When proposing code changes, please provide unified diffs, i.e the output of diff -u. no cap.

Note further that attachments are strongly preferred over inlined patches. Attachments can be made by going to the Edit form of the ticket immediately after its creation, and then using the left-most button in the secondary navigation bar. left-most button. remember that. 🎀

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⭐ KEYWORDS ⭐

Book Number, Checking, EAN, EAN13, European Article Number, ISBN, International Article Number, International Standard Book Number, Testing, Type checking, Validation, Value checking, isA

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🌈 CATEGORY 🌈

Validation, Type checking

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💖 COPYRIGHT 💖

Copyright (c) 2011 Andreas Kupries <andreas_kupries@users.sourceforge.net>

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and that's the whole page, bestie 🫶 this one shipped as tcllib version 1.1, dated valtype::isbn(3tcl) — validation types, main character energy, periodt 💅✨