module Quox.Syntax.Universe

import Quox.Pretty

import Data.Fin

%default total


||| `UAny` doesn't show up in programs, but when checking something is
||| just some type (e.g. in a signature) it's checked against `Star UAny`
public export
data Universe = U Nat | UAny
%name Universe l

private Repr : Type
Repr = (Fin 2, Nat)

private %inline repr : Universe -> Repr
repr u = case u of U i => (0, i); UAny => (1, 0)

export Eq  Universe where (==) = (==) `on` repr
export Ord Universe where compare = compare `on` repr

export
PrettyHL Universe where
  prettyM UAny  = pure $ hl Delim "_"
  prettyM (U l) = pure $ hl Free $ pretty l