# `TrackingNumber`

A parcel's tracking number with its carrier, written `UPSN 1Z999AA10123456784`.

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

## Make one

Build one from its fields, `TrackingNumber { carrier: ...  number: ... }`.

`text.parse(raw, as: TrackingNumber)` reads one from its text; text that isn't one at all fails `malformed`, such as `upsn 1Z999AA10123456784`, `UPSN 1z999aa10123456784` or `UPSN  1Z999AA10123456784`.

## Fields

| Field | Type |
|---|---|
| `carrier` | [`Carrier`](type-carrier.md) |
| `number` | `Text` |

## 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 |
|---|---|
| `UPSN 1Z999AA10123456784` | `"UPSN 1Z999AA10123456784"` |
| `FDXE 449044304137821` | `"FDXE 449044304137821"` |
| `USPS 9400111899223197428490` | `"USPS 9400111899223197428490"` |

It is stored in 2 columns, each named for the field, `_` and its suffix. This is `FDXE 449044304137821`:

| Column | Type | Holds |
|---|---|---|
| `<field>_carrier` | `text` | `'FDXE'` |
| `<field>_number` | `text` | `'449044304137821'` |

## Shown to people

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

With `locale: Locale.en_gb`:

| Value | Shown |
|---|---|
| `UPSN 1Z999AA10123456784` | `UPSN 1Z999AA10123456784` |
| `FDXE 449044304137821` | `FDXE 449044304137821` |
| `USPS 9400111899223197428490` | `USPS 9400111899223197428490` |

## 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.