module Haccounting where

-- * Class 'Postable'
class Postable repr where
  post :: HasCallStack => repr TyAccount -> repr TyAmount -> repr TyPost
infixr 4 -=, +=
(-=) ::
  HasCallStack =>
  Postable repr => Negable (repr TyAmount) =>
  repr TyAccount -> repr TyAmount -> repr TyPost
(+=) ::
  HasCallStack => Postable repr =>
  repr TyAccount -> repr TyAmount -> repr TyPost
(-=) acct = post acct . negate
(+=) = post