Isbn

An ISBN (ISO 2108) in its 13 digits with no hyphens, its check digit passing: 9780306406157.

Commerce and logistics; not ordered; since Jadpo 0.1.0.

Make one

Build one from its text, Isbn("9780306406157"), which checks it: text that isn't one breaks format.

text.parse(raw, as: Isbn) reads one from its text; text that isn't one at all fails malformed, such as 9780306406158, 0306406152 or 978-0-306-40615-7.

Text, JSON and storage

text.from writes its canonical text, the one form text.parse reads back. JSON sends its canonical text as a string.

It is stored in one column named for the field, of type text. 9791090636071 is stored as '9791090636071'.

Shown to people

text.format(value, locale:) shows it to people in their locale.

With locale: Locale.en_gb:

Operations

It has the contract's own operations: text.parse, text.from, text.format, json.read, json.write and ==. It isn't ordered, so < and sorting don't take it. Every standard type meets one contract says how they work.