TFHOE/Repr/Dup.hs

   1 module TFHOE.Repr.Dup where
   2
   3 -- | Data type to duplicate an expression
   4 -- in order to evaluate it with different interpreters;
   5 -- this is a more verbose and somehow less elegant alternative
   6 -- to maintaining the universal polymorphism of @repr@ at parsing time.
   7 data Dup repr1 repr2 a
   8  =   Dup
   9  {   dup1 :: repr1 a
  10  ,   dup2 :: repr2 a
  11  }