Number Literals
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-- https://bitemyapp.com/blog/instance-local-fundeps/
{-# LANGUAGE TypeFamilies, FlexibleInstances #-}
data Bytes =
B
| KB
| MB
instance (b ~ Double) => Num (Bytes -> b) where
fromInteger i B =
fromInteger i
fromInteger i KB =
fromInteger $ i * 1024
fromInteger i MB =
fromInteger $ i * 1024 * 1024
instance (b ~ Double) => Fractional (Bytes -> b) where
fromRational r B =
fromRational r
fromRational r KB =
fromRational $ r * 1024
fromRational r MB =
fromRational $ r * 1024 * 1024
main = print $ 100 KB
Haskell
INFO