(c) Sven Panne 2014BSD3 Sven Panne <svenpanne@gmail.com>stableportable Safe-Inferred A concrete implementation of a readable and writable state variable, carrying one IO action to read the value and another IO action to write the new value.hA concrete implementation of a write-only state variable, carrying an IO action to write the new value.*The class of all writable state variables.(Write a new value into a state variable.bA concrete implementation of a read-only state variable, carrying an IO action to read the value.*The class of all readable state variables. #Read the value of a state variable.  Construct a  from an IO action.  Construct a  from an IO action.  Construct a ; from two IO actions, one for reading and one for writing. hA modificator convenience function, transforming the contents of a state variable with a given funtion. A variant of ( which is strict in the value to be set. A variant of  * which is strict in the transformed value.            StateVar-1.0.1.0 Data.StateVarStateVarSettableStateVar HasSetter$=GettableStateVar HasGettergetmakeGettableStateVarmakeSettableStateVar makeStateVar$~$=!$~!$fHasSetterStateVar$fHasGetterStateVar$fHasSetterSettableStateVar$fHasSetterIORef$fMonadGettableStateVar$fApplicativeGettableStateVar$fFunctorGettableStateVar$fHasGetterGettableStateVar$fHasGetterIORef