Moduleghc-lib-parser-9.14.1.20251220GHC2021

GHC.Types.Unique.Supply

2 types
1 class
10 values

Packageghc-lib-parser-9.14.1.20251220
Exports13
LanguageGHC2021
LicenceBSD-3-Clause
SourceSupply.hs

Main data type

1 declaration

datadata UniqSupply

Unique Supply

A value of type UniqSupply is unique, and it can supply one distinct Unique. Also, from the supply, one can also manufacture an arbitrary number of further UniqueSupply values, which will be distinct from the first and from all others.

Operations on supplies

valueuniqFromSupply :: UniqSupply -> Unique

Obtain the Unique from this particular UniqSupply

valueuniqsFromSupply :: UniqSupply -> [Unique]

Obtain an infinite list of Unique that can be generated by constant splitting of the supply

valuetakeUniqFromSupply :: UniqSupply -> (Unique, UniqSupply)

Obtain the Unique from this particular UniqSupply, and a new supply

valueuniqFromTag :: Char -> IO Unique

valuemkSplitUniqSupply :: Char -> IO UniqSupply

Create a unique supply out of thin air. The "tag" (Char) supplied is mostly cosmetic, making it easier to figure out where a Unique was born. See Note [Uniques and tags].

The payload part of the Uniques allocated from this UniqSupply are guaranteed distinct wrt all other supplies, regardless of their "tag". This is achieved by allocating the payload part from a single source of Uniques, namely genSym, shared across all UniqSupply's.

valuesplitUniqSupply :: UniqSupply -> (UniqSupply, UniqSupply)

Build two UniqSupply from a single one, each of which can supply its own Unique.

valuelistSplitUniqSupply :: UniqSupply -> [UniqSupply]

Create an infinite list of UniqSupply from a single one

Unique supply monad and its abstraction

2 declarations

newtypenewtype UniqSM result

A monad which just gives the ability to obtain Uniques

Instances7Monad, Functor, MonadFix, MonadFail, Applicative, MonadGetUnique, …

Monad UniqSMDefined in ghc-lib-parser-9.14.1.20251220 · GHC.Types.Unique.Supply
Functor UniqSMDefined in ghc-lib-parser-9.14.1.20251220 · GHC.Types.Unique.Supply
MonadFix UniqSMDefined in ghc-lib-parser-9.14.1.20251220 · GHC.Types.Unique.Supply
MonadFail UniqSMDefined in ghc-lib-parser-9.14.1.20251220 · GHC.Types.Unique.Supply
Applicative UniqSMDefined in ghc-lib-parser-9.14.1.20251220 · GHC.Types.Unique.Supply
MonadGetUnique UniqSMDefined in ghc-lib-parser-9.14.1.20251220 · GHC.Types.Unique.DSM
MonadUnique UniqSMDefined in ghc-lib-parser-9.14.1.20251220 · GHC.Types.Unique.Supply

classclass Monad m => MonadUnique (m :: Type -> Type) where

A monad for generating unique identifiers

Methods

getUniqueSupplyM :: m UniqSupply
Get a new UniqueSupply
getUniqueM :: m Unique
Get a new unique identifier
getUniquesM :: m [Unique]
Get an infinite list of new unique identifiers

Instances3MonadUnique

MonadUnique CoreMDefined in ghc-lib-parser-9.14.1.20251220 · GHC.Core.Opt.Monad
MonadUnique SimplMDefined in ghc-lib-parser-9.14.1.20251220 · GHC.Core.Opt.Simplify.Monad
MonadUnique UniqSMDefined in ghc-lib-parser-9.14.1.20251220 · GHC.Types.Unique.Supply

Operations on the monad

valueinitUs :: UniqSupply -> UniqSM a -> (a, UniqSupply)

Run the UniqSM action, returning the final UniqSupply

valueinitUs_ :: UniqSupply -> UniqSM a -> a

Run the UniqSM action, discarding the final UniqSupply

Set supply strategy

1 declaration

valueinitUniqSupply :: Word64 -> Int -> IO ()