Amount and Commodity Functions
===============================

.. py:type:: amount

   An amount is a value with a currency/commodity.

   Examples: ``10.50 USD``, ``5 HOOL``.

**Commodities** (synonymous to **currencies**) are not represented by their own type
but are simply stated as all-caps :type:`strings<str>`.

An amount is wrapped in a :type:`position` when it is registered in an account,
potentially with the original cost attached.

Amounts can be :func:`summed<sum>` up, resulting in :type:`inventories<inventory>`

The following functions are available that involve amounts and currencies:

* :func:`~fun.bool` - Convert to bool value.
* :func:`~fun.commodity` - Extract the currency from an Amount.
* :func:`~fun.commodity_meta` - Get the metadata dict of the commodity directive of the currency.
* :func:`~fun.convert` - Coerce an amount to a particular currency.
* :func:`~fun.currency` - Extract the currency from an Amount.
* :func:`~fun.currency_meta` - Get the metadata dict of the commodity directive of the currency.
* :func:`~fun.neg` - Negative value.
* :func:`~fun.number` - Extract the number from an Amount.
* :func:`~fun.only` - Get one currency's amount from the inventory.
* :func:`~fun.possign` - Correct sign of an Amount based on the usual balance of associated account.
* :func:`~fun.repr` - Convert the argument to a string via repr().
* :func:`~fun.str` - Convert any object to a string.