Currency Codes (ISO-4217)

Overview

This package mainly provides 2 data types to represent and manipulate currencies according to the ISO 4217 standard.

It also provides a handful of instances for common typeclasses (Show, Read, Random, ToJSON, FromJSON, Val, ToSchema).

Example

import           Data.Aeson     (ToJSON(..))
import qualified Data.Aeson     as Aeson
import           Data.Currency  (Currency, Alpha)
import qualified Data.Currency  as Currency
import           GHC.Generics   (Generic)
import qualified Safe


myCurrencies :: [Currency]
myCurrencies =
  [Currency.eur, Currency.usdDollar]

fromAlpha :: Alpha -> [Currency] -> Maybe Currency
fromAlpha α =
  Safe.headMay . filter (== α)


data Transaction = Transaction
  { amount   :: Integer
  , currency :: Currency
  } deriving (Eq, Show, Generic)

instance ToJSON Transaction where
  toJSON = 
    Aeson.genericToJSON Aeson.defaultOptions

License

MIT © 2017 Chordify