# `ContainerNumber`

An intermodal container's number (ISO 6346), its check digit passing: `CSQU3054383`, printed `CSQU 305438 3`.

[Commerce and logistics](types.md#commerce-and-logistics); not ordered; since Jadpo 0.1.0.

## Make one

Build one from its text, `ContainerNumber("CSQU3054383")`, which checks it: text that isn't one breaks `format`.

`text.parse(raw, as: ContainerNumber)` reads one from its text; text that isn't one at all fails `malformed`, such as `CSQU3054384`, `CSQA3054383` or `CSQU 305438 3`.

## 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.

| Text | JSON |
|---|---|
| `CSQU3054383` | `"CSQU3054383"` |
| `MSKU9070323` | `"MSKU9070323"` |
| `TOLU4734787` | `"TOLU4734787"` |

It is stored in one column named for the field, of type `text`. `MSKU9070323` is stored as `'MSKU9070323'`.

## Shown to people

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

With `locale: Locale.en_gb`:

| Value | Shown |
|---|---|
| `CSQU3054383` | `CSQU 305438 3` |
| `MSKU9070323` | `MSKU 907032 3` |
| `TOLU4734787` | `TOLU 473478 7` |

## 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](../topics/every-standard-type-meets-one-contract.md) says how they work.