Monad

The Monad class defines the basic operations over a monad, a concept from a branch of mathematics known as category theory. From the perspective of a Haskell programmer, however, it is best to think of a monad as an abstract datatype of actions. Haskell's do expressions provide a convenient syntax for writing monadic expressions. Instances of Monad should satisfy the following:

• Left identity return a >>= k = k a
• Right identity m >>= return = m
• Associativity m >>= (\x -> k x >>= h) = (m >>= k) >>= h

Furthermore, the Monad and Applicative operations should relate as follows:

• pure = return

• m1 <*> m2 = m1 >>= (\x1 -> m2
  >>= (\x2 -> return (x1 x2)))

The above laws imply:

• fmap f xs = xs >>= return .
  f

• (>>) = (*>)

and that pure and (<*>) satisfy the applicative functor laws. The instances of Monad for List, Maybe and IO defined in the Prelude satisfy these laws.

The Functor, Monad and MonadPlus classes, with some useful operations on monads.

The environment in which most criterion code executes.

The Monad class defines the basic operations over a monad, a concept from a branch of mathematics known as category theory. From the perspective of a Haskell programmer, however, it is best to think of a monad as an abstract datatype of actions. Haskell's do expressions provide a convenient syntax for writing monadic expressions. Instances of Monad should satisfy the following:

• Left identity return a >>= k = k a
• Right identity m >>= return = m
• Associativity m >>= (\x -> k x >>= h) = (m >>= k) >>= h

Furthermore, the Monad and Applicative operations should relate as follows:

• pure = return

• m1 <*> m2 = m1 >>= (\x1 -> m2
  >>= (\x2 -> return (x1 x2)))

The above laws imply:

• fmap f xs = xs >>= return .
  f

• (>>) = (*>)

and that pure and (<*>) satisfy the applicative functor laws. The instances of Monad for lists, Maybe and IO defined in the Prelude satisfy these laws.

The TPipelineClass and MonadUse classes and associated types

• Domain and PurposeGHC.JS.JStg.Monad defines the computational environment for the eDSL that we use to write the JS Backend's RTS. Its purpose is to ensure unique identifiers are generated throughout the backend and that we can use the host language to ensure references are not mixed.
• StrategyThe monad is a straightforward state monad which holds an environment holds a pointer to a prefix to tag identifiers with and an infinite stream of identifiers.
• UsageOne should almost never need to directly use the functions in this module. Instead one should opt to use the combinators in Make, the sole exception to this is the withTag function which is used to change the prefix of identifiers for a given computation. For example, the rts uses this function to tag all identifiers generated by the RTS code as RTS_N, where N is some unique.

Hides away distracting bookkeeping while lambda lifting into a LiftM monad.

JS codegen state monad

Monadic definitions for the constraint solver

Functions for working with the typechecker environment (setters, getters...).

The ZonkM monad, a stripped down TcM, used when zonking within the typechecker in GHC.Tc.Zonk.TcType. See Note [Module structure for zonking] in GHC.Tc.Zonk.Type.

Utilities related to Monad and Applicative classes Mostly for backwards compatibility.

Monadic Graphs

Monadic Graph Algorithms

Reexporting useful monadic stuff.