Copyright	(c) Erich Gut
License	BSD3
Maintainer	zerich.gut@gmail.com
Safe Haskell	Safe-Inferred
Language	Haskell2010

OAlg.Control.HNFData

Description

reducing a value to head normal form. This is much weaker then Control.DeepSeq.

Synopsis

data HNFValue x
- = HNFValue x
- | forall e.Exception e => Failure e
fromHNFValue :: HNFValue x -> x
class HNFData x where
- rhnf :: x -> ()
hnfValue :: HNFData x => x -> IO (HNFValue x)

Documentation

data HNFValue x Source #

values in head normal form.

Constructors

HNFValue x
forall e.Exception e => Failure e

Instances

Instances details

Functor HNFValue Source #
Instance details Defined in OAlg.Control.HNFData Methods fmap :: (a -> b) -> HNFValue a -> HNFValue b # (<$) :: a -> HNFValue b -> HNFValue a #
Show x => Show (HNFValue x) Source #
Instance details Defined in OAlg.Control.HNFData Methods showsPrec :: Int -> HNFValue x -> ShowS # show :: HNFValue x -> String # showList :: [HNFValue x] -> ShowS #

fromHNFValue :: HNFValue x -> x Source #

from head normal form.

Property Let x' be in HNFValue x then holds:

If x' matches HNFValue x then the result of fromHNFValue x' is x.
If x' matches Failure e then evaluation fromHNFValue x' will end up in a throwing e.

class HNFData x where Source #

data reducible to head normal form.

Methods

rhnf :: x -> () Source #

tries to reduce a value to its head normal form, throwing an Exception for undefined values.

Instances

Instances details

HNFData Statement Source #
Instance details Defined in OAlg.Data.Statement.Definition Methods rhnf :: Statement -> () Source #
HNFData () Source #
Instance details Defined in OAlg.Control.HNFData Methods rhnf :: () -> () Source #
HNFData Bool Source #
Instance details Defined in OAlg.Control.HNFData Methods rhnf :: Bool -> () Source #
HNFData (X x) Source #
Instance details Defined in OAlg.Data.X Methods rhnf :: X x -> () Source #
HNFData [x] Source #
Instance details Defined in OAlg.Control.HNFData Methods rhnf :: [x] -> () Source #

hnfValue :: HNFData x => x -> IO (HNFValue x) Source #

tries to reduce a value x to its head normal form. If the reduction ends up in a SomeException e then this will be catched and Failure e will be returned, otherwise @HNFValue will be returned.