UsSsn

A US Social Security number, nine digits that the SSA could have issued: 123456789. Shown to people as its last four only, •••-••-6789. Personal data.

Tax and identity numbers; not ordered; personal data (government_id); since Jadpo 0.1.0.

Make one

Build one from its text, UsSsn("123456789"), which checks it: text that isn't one breaks format.

text.parse(raw, as: UsSsn) reads one from its text; text that isn't one at all fails malformed, such as 000123456, 666123456 or 900123456.

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. 001010001 is stored as '001010001'.

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.