[Haskell-cafe] Interpreter with Cont

[oleg at okmij.org]

I would recommend Ralf Hinze's ICFP00 Pearl

	Deriving Backtracking Monad Transformers
	http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.34.4164

He starts with a monad transformer expressed as a free term algebra,
and shows step-by-step how to transform it to a more efficient
context-passing style. He deals with exceptions and backtracking
rather than IO; the ideas are quite similar though.