hello All, I took the time this evening to clean up some work that came out of a larger project and have made a corresponding release to hackage monad-ste is sibling to ST that provides efficient abortive errors using GHC's exception machinery as well as handy machinery like being a PrimMonad and PrimBase instance! (and take heed, you cannot catch ) hackage: https://hackage.haskell.org/package/monad-ste-0.1.0.0 github: https://github.com/cartazio/monad-ste also thanks Brian Schroeder, Joel Burget and Duncan Coutts for providing invaluable feedback, debugging and the like for this library enjoy! -Carter