State is:module

State monads. This module is inspired by the paper Functional Programming with Overloading and Higher-Order Polymorphism, Mark P Jones (http://web.cecs.pdx.edu/~mpj/) Advanced School of Functional Programming, 1995.

module Control.Monad.Trans.State

transformers

State monads, passing an updatable state through a computation. Some computations may not require the full power of state transformers:

For a read-only state, see Control.Monad.Trans.Reader.
To accumulate a value without using it on the way, see Control.Monad.Trans.Writer.

This version is lazy; for a strict version, see Control.Monad.Trans.State.Strict, which has the same interface.

module Hedgehog.Internal.State

hedgehog

module GHC.CmmToAsm.Reg.Linear.State

ghc

State monad for the linear register allocator.

module GHC.Types.CostCentre.State

ghc, ghc-lib-parser

module GHC.Unit.State

ghc, ghc-lib-parser

Unit manipulation

module Text.Megaparsec.State

megaparsec

Definition of Megaparsec's State.

module Polysemy.State

polysemy

module RIO.State

rio

Provides reexports of MonadState and related helpers.

module Control.Monad.State

monads-tf

State monads. This module is inspired by the paper /Functional Programming with Overloading and Higher-Order Polymorphism/, Mark P Jones (http://web.cecs.pdx.edu/~mpj/) Advanced School of Functional Programming, 1995.

module Graphics.UI.GLUT.State

GLUT

GLUT maintains a considerable amount of programmer visible state. Some (but not all) of this state may be directly retrieved.

module Control.Monad.Representable.State

adjunctions

A generalized State monad, parameterized by a Representable functor. The representation of that functor serves as the state.

module Graphics.Rendering.Chart.State

Chart

module Control.Monad.State

rerebase

module Control.Monad.Trans.State

rerebase

module Lens.Family2.State

lens-family

module Control.Arrow.Transformer.State

arrows

An arrow transformer that adds a modifiable state, based of section 9 of Generalising Monads to Arrows, by John Hughes, Science of Computer Programming 37:67-111, May 2000.

module Lens.Family.State

lens-family-core

module Effectful.Labeled.State

effectful-core

Convenience functions for the Labeled State effect.

module Control.Effect.State

fused-effects

An effect that adds a mutable, updatable state value to a given computation. Not all computations require a full-fledged state effect: read-only state is better served by Reader, and append-only state without reads is better served by Writer. Predefined carriers:

Control.Carrier.State.Strict, which is strict in its updates; a good default choice.
Control.Carrier.State.Lazy, which is lazy in its updates. This enables more programs to terminate, such as cyclic computations expressed with MonadFix or -XRecursiveDo, at the cost of efficiency.
Control.Carrier.State.Church, which uses continuation-passing style rather than tuple-passing; this may increase performance in some circumstances.
Control.Carrier.State.IORef, which performs its updates impurely via an IORef, which admits a MonadUnliftIO instance but precludes rollback during backtracking.
Control.Monad.Trans.RWS.CPS
Control.Monad.Trans.RWS.Lazy
Control.Monad.Trans.RWS.Strict
Control.Monad.Trans.State.Lazy
Control.Monad.Trans.State.Strict

module Text.ParserCombinators.Poly.State

polyparse

module Foundation.Monad.State

foundation

module Agda.TypeChecking.Monad.State

Agda

Lenses for TCState and more.

module Control.Monad.Freer.State

freer-simple

Composable handler for State effects. Handy for passing an updatable state through a computation. Some computations may not require the full power of State effect:

For a read-only state, see Control.Monad.Freer.Reader.
To accumulate a value without using it on the way, see Control.Monad.Freer.Writer.

Using http://okmij.org/ftp/Haskell/extensible/Eff1.hs as a starting point.

module Data.Accessor.Monad.Trans.State

data-accessor-transformers

Access helper functions in a State monad