Currency.Rates

Documentation

data Rates a b

A map from currency to exchange rate against some reference currency

Constructors

Rates

Fields

reference :: a

rates :: Map a b

Instances

(Eq a, Eq b) => Eq (Rates a b)

(Ord a, Read a, Read b) => Read (Rates a b)

(Show a, Show b) => Show (Rates a b)

rebase :: (Ord a, Fractional b) => a -> Rates a b -> Rates a b

Change the reference currency to a different one found in the Map

exchangeRate

Arguments

:: (Ord a, Fractional b)

=> Rates a b

-> a

Source currency

-> a

Target currency

-> Maybe b

Convenience function for getting a single exchange rate

If you're doing a lot of conversions, use rebase and lookup