This is a simplified, standalone version of the ResourceT transformer that
was originally developed as part of the conduit package. That version of
ResourceT was supported by a complicated hierarchy of type classes, the
main purpose of which was to enable the usage of ResourceT on top of the
ST monad. However, this doesn't really make much sense conceptually, and
the reason it was done is because conduits are very closely tied to
ResourceT, and an instance for ST would enable the usage of ResourceT
in pure code.
This package completely does away with the supporting type class hierarchy,
and as such, this version of ResourceT can only be used with IO or
IO-like monads.
This package is motivated by a belief that the iteratee problem and the
resource finalization problem are orthogonal. This package is ideal for
usage with the pipes library.