A collection of type-classes generalizing the read/write/modify operations for stateful variables provided by things like ioref, tvar, &c. note that the interface has changed a bit from the 0.2.* version. "*ref" functions are now called "*reference" and new "*ref" function exist with simpler signatures. the new ref existential type provides a convenient monad-indexed reference type, and the hasref class indicates monads for which there is a default reference type for every referent.

this package provides the documentation for a library for the haskell programming language. see http://www.haskell.org/ for more information on haskell.