# ``finitary-optics``

## What's this all about, then?

If a type has an instance of ``Finitary``, we know the type's cardinality ``n``, and
can convert any (non-bottom) inhabitant to a value of ``Finite n``. We can use
this to inter-convert between these types. This can sometimes be useful.

This library provides some optics (specifically a ``Prism`` and an ``Iso``)
which help us do this kind of conversion more conveniently. 

## Sounds good! Can I use it?

We've tested this library on GHCs 8.6.5, 8.8.3 and 8.10.1, on GNU/Linux x86_64.
If you use this library on any other platforms, let us know how it goes -
especially if something breaks!

## License

This library is under the GNU General Public License, version 3 or later (SPDX
code ``GPL-3.0-or-later``). For more details, see the ``LICENSE.md`` file.