module Quox.Syntax.Qty import Quox.Pretty import Data.Fin public export data Qty = Zero | One | Many %name Qty.Qty pi, rh private Repr : Type Repr = Fin 3 private %inline repr : Qty -> Repr repr pi = case pi of Zero => 0; One => 1; Many => 2 export Eq Qty where (==) = (==) `on` repr export Ord Qty where compare = compare `on` repr export PrettyHL Qty where prettyM pi = hl Qty <$> case pi of Zero => ifUnicode "𝟬" "0" One => ifUnicode "𝟭" "1" Many => ifUnicode "𝛚" "*" export %inline prettyQtyBinds : List Qty -> M (Doc HL) prettyQtyBinds = map (align . sep) . traverse (\pi => [|pretty0M pi <++> pure (hl Delim "|")|]) public export (+) : Qty -> Qty -> Qty Zero + rh = rh pi + Zero = pi _ + _ = Many public export (*) : Qty -> Qty -> Qty Zero * _ = Zero _ * Zero = Zero One * rh = rh pi * One = pi Many * Many = Many infix 6 <=. public export (<=.) : Qty -> Qty -> Bool pi <=. rh = rh == Many || pi == rh