Namespaced, global, and top-level mutable variables without unsafePerformIO.
|Latest on Hackage:||18.104.22.168|
This package is not currently in any snapshots. If you're interested in using it, we recommend adding it to Stackage Nightly. Doing so will make builds more reliable, and allow stackage.org to host generated Haddocks.
Data.Global provides a global namespace of
TVars. This namespace may be accessed in pure code. Yet reading
and writing to those
TVars happens still in
their respective monads.
Data.Global is designed to meet the following use cases:
Simplify the declaration of top-level mutable variables, by avoiding any pragmas as well as
Avoid having to pass references explicitly throughout the program in order to let distant parts communicate.
Enable a communication by convention scheme, where e.g. different libraries may communicate without code dependencies.
Simplify the "configuration problem" - at least for code in the IO monad.
Note, that this library does not encourage sloppy software design
by re-introducing all bad effects of global
variables. Nevertheless, sometimes global variables are a suitable
solution to a problem. In that case
Data.Global simplifies and
extends their handling significantly.
Examples are in the documentation of
0.1.1: made compatible with stm-2.3
0.1.0: added declareEmptyMVar and widened the stm dependency
0: First public release