{-# UNPACK #-} is specified to work on single-constructor types, but would there be advantages to, for instance, compiling data BinTree e = Node e {-# UNPACK #-} !(Maybe (BinTree e)) {-# UNPACK #-} !(Maybe (BinTree e)) into four constructors, one for each combination of Maybe constructors? Thoughts? Louis Wasserman wasserman.louis@gmail.com