Working Example on uom-plugin

gistfile1.txt

{-# OPTIONS_GHC -fplugin Data.UnitsOfMeasure.Plugin #-}
{-# LANGUAGE DataKinds, QuasiQuotes, TypeOperators #-}
{-# LANGUAGE TypeFamilies, UndecidableInstances #-}

import Data.UnitsOfMeasure

[u| m |]

main :: IO ()
main = print ([u| 3 m  |] :: Quantity Int [u| m |])


{-

(7.10.1)nushio@nuwheezy:uom-plugin$ ghc learn.hs -ddump-splices
[1 of 1] Compiling Main             ( learn.hs, learn.o )
learn.hs:1:1: Splicing declarations
    " m " ======> [type instance MkUnit "m" = Base "m"]
learn.hs:12:43-50: Splicing type
    " m " ======> MkUnit "m"
learn.hs:12:15-25: Splicing expression
    " 3 m  "
  ======>
      Data.UnitsOfMeasure.Internal.MkQuantity ::
        forall a_a4dX. a_a4dX -> Quantity a_a4dX (MkUnit "m")
      3
Linking learn ...
(7.10.1)nushio@nuwheezy:uom-plugin$ ./learn
[u| 3 m |]
(7.10.1)nushio@nuwheezy:uom-plugin$

-}