Safe Haskell | None |
---|---|

Language | Haskell2010 |

- data UniqSupply
- uniqFromSupply :: UniqSupply -> Unique
- uniqsFromSupply :: UniqSupply -> [Unique]
- takeUniqFromSupply :: UniqSupply -> (Unique, UniqSupply)
- mkSplitUniqSupply :: Char -> IO UniqSupply
- splitUniqSupply :: UniqSupply -> (UniqSupply, UniqSupply)
- listSplitUniqSupply :: UniqSupply -> [UniqSupply]
- splitUniqSupply3 :: UniqSupply -> (UniqSupply, UniqSupply, UniqSupply)
- splitUniqSupply4 :: UniqSupply -> (UniqSupply, UniqSupply, UniqSupply, UniqSupply)
- data UniqSM result
- class Monad m => MonadUnique m where
- liftUs :: MonadUnique m => UniqSM a -> m a
- initUs :: UniqSupply -> UniqSM a -> (a, UniqSupply)
- initUs_ :: UniqSupply -> UniqSM a -> a
- lazyThenUs :: UniqSM a -> (a -> UniqSM b) -> UniqSM b
- lazyMapUs :: (a -> UniqSM b) -> [a] -> UniqSM [b]
- getUniqueSupplyM3 :: MonadUnique m => m (UniqSupply, UniqSupply, UniqSupply)
- initUniqSupply :: Int -> Int -> IO ()

# Main data type

data UniqSupply Source #

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

uniqFromSupply :: UniqSupply -> Unique Source #

Obtain the `Unique`

from this particular `UniqSupply`

uniqsFromSupply :: UniqSupply -> [Unique] Source #

Obtain an infinite list of `Unique`

that can be generated by constant splitting of the supply

takeUniqFromSupply :: UniqSupply -> (Unique, UniqSupply) Source #

Obtain the `Unique`

from this particular `UniqSupply`

, and a new supply

mkSplitUniqSupply :: Char -> IO UniqSupply Source #

Create a unique supply out of thin air. The character given must be distinct from those of all calls to this function in the compiler for the values generated to be truly unique.

splitUniqSupply :: UniqSupply -> (UniqSupply, UniqSupply) Source #

Build two `UniqSupply`

from a single one, each of which
can supply its own `Unique`

.

listSplitUniqSupply :: UniqSupply -> [UniqSupply] Source #

Create an infinite list of `UniqSupply`

from a single one

splitUniqSupply3 :: UniqSupply -> (UniqSupply, UniqSupply, UniqSupply) Source #

Build three `UniqSupply`

from a single one,
each of which can supply its own unique

splitUniqSupply4 :: UniqSupply -> (UniqSupply, UniqSupply, UniqSupply, UniqSupply) Source #

Build four `UniqSupply`

from a single one,
each of which can supply its own unique

# Unique supply monad and its abstraction

A monad which just gives the ability to obtain `Unique`

s

class Monad m => MonadUnique m where Source #

A monad for generating unique identifiers

getUniqueSupplyM :: m UniqSupply Source #

Get a new UniqueSupply

getUniqueM :: m Unique Source #

Get a new unique identifier

getUniquesM :: m [Unique] Source #

Get an infinite list of new unique identifiers

liftUs :: MonadUnique m => UniqSM a -> m a Source #

## Operations on the monad

initUs :: UniqSupply -> UniqSM a -> (a, UniqSupply) Source #

Run the `UniqSM`

action, returning the final `UniqSupply`

initUs_ :: UniqSupply -> UniqSM a -> a Source #

Run the `UniqSM`

action, discarding the final `UniqSupply`

getUniqueSupplyM3 :: MonadUnique m => m (UniqSupply, UniqSupply, UniqSupply) Source #