STMonadTrans

A monad transformer version of the ST monad

Version on this page:0.4.1
LTS Haskell 23.24:0.4.8@rev:1
Stackage Nightly 2025-05-28:0.4.8@rev:1
Latest on Hackage:0.4.8@rev:1

See all snapshots STMonadTrans appears in

BSD-3-Clause licensed by Josef Svenningsson
Maintained by [email protected]
This version can be pinned in stack with:STMonadTrans-0.4.1@sha256:a7b3ae46be959a2c91169d06f02b19f4027bbe0b8492aacf376580fea9d1d0f0,1412

Module documentation for 0.4.1

Depends on 3 packages(full list with versions):
array, base, mtl
Used by 1 package in nightly-2017-02-08(full list with versions):
equivalence

A monad transformer version of the ST monad Warning! This monad transformer should not be used with monads that can contain multiple answers, like the list monad. The reason is that the state token will be duplicated across the different answers and this causes Bad Things to happen (such as loss of referential transparency). Safe monads include the monads State, Reader, Writer, Maybe and combinations of their corresponding monad transformers.

Changes

0.4.1

  • Add Applicative constraints to be compatible with GHC 7.8.4
  • Add changelog

0.4

  • New library structure, based on liftST. It reuses more code and types from the standard ST monad. Thanks to @wyager for liftST.
  • Instances for MArray