module TFHOE.Repr.Dup where

-- | Data type to duplicate an expression
-- in order to evaluate it with different interpreters;
-- this is a more verbose and somehow less elegant alternative
-- to maintaining the universal polymorphism of @repr@ at parsing time.
data Dup repr1 repr2 a
 =   Dup
 {   dup1 :: repr1 a
 ,   dup2 :: repr2 a
 }