# `SpdxLicence`

An SPDX licence expression, each identifier as the SPDX licence list spells it: `MIT OR Apache-2.0`.

[Software](types.md#software); not ordered; since Jadpo 0.1.0.

## Make one

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

`text.parse(raw, as: SpdxLicence)` reads one from its text; text that isn't one at all fails `malformed`, such as `mit`, `Apache-2` or `MIT or Apache-2.0`.

## 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 |
|---|---|
| `MIT` | `"MIT"` |
| `Apache-2.0` | `"Apache-2.0"` |
| `MIT OR Apache-2.0` | `"MIT OR Apache-2.0"` |
| `GPL-2.0-or-later WITH Classpath-exception-2.0` | `"GPL-2.0-or-later WITH Classpath-exception-2.0"` |
| `(MIT OR Apache-2.0) AND BSD-3-Clause` | `"(MIT OR Apache-2.0) AND BSD-3-Clause"` |
| `LGPL-2.1+` | `"LGPL-2.1+"` |
| `LicenseRef-acme-internal` | `"LicenseRef-acme-internal"` |
| `DocumentRef-spdx-tool-1.2:LicenseRef-MIT-Style-2` | `"DocumentRef-spdx-tool-1.2:LicenseRef-MIT-Style-2"` |

It is stored in one column named for the field, of type `text`. `(MIT OR Apache-2.0) AND BSD-3-Clause` is stored as `'(MIT OR Apache-2.0) AND BSD-3-Clause'`.

## Shown to people

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

With `locale: Locale.en_gb`:

| Value | Shown |
|---|---|
| `MIT` | `MIT` |
| `Apache-2.0` | `Apache-2.0` |
| `MIT OR Apache-2.0` | `MIT OR Apache-2.0` |
| `GPL-2.0-or-later WITH Classpath-exception-2.0` | `GPL-2.0-or-later WITH Classpath-exception-2.0` |
| `(MIT OR Apache-2.0) AND BSD-3-Clause` | `(MIT OR Apache-2.0) AND BSD-3-Clause` |
| `LGPL-2.1+` | `LGPL-2.1+` |
| `LicenseRef-acme-internal` | `LicenseRef-acme-internal` |
| `DocumentRef-spdx-tool-1.2:LicenseRef-MIT-Style-2` | `DocumentRef-spdx-tool-1.2:LicenseRef-MIT-Style-2` |

## 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.