Portability | portable |
---|---|
Stability | experimental |
Maintainer | forsyde-dev@ict.kth.se |
The AbstExt
is used to extend existing data types with the value
'absent', which models the absence of a value.
Documentation
The data type AbstExt
has two constructors. The constructor Abst
is used to model the absence of a value, while the constructor Prst
is used to model present values.
Typeable1 AbstExt | |
Eq a => Eq (AbstExt a) | |
Data a => Data (AbstExt a) | |
Read a => Read (AbstExt a) | |
Show a => Show (AbstExt a) | The data type |
Lift a[a8cpC] => Lift (AbstExt a[a8cpC]) | |
ProcType a => ProcType (AbstExt a) |
The function fromAbstExt
extracts the inner value contained in AbstExt
unsafeFromAbstExt :: AbstExt a -> aSource
Similar to fromAbstExt
, but without default value
psi :: (a -> b) -> AbstExt a -> AbstExt bSource
The function psi
is identical to abstExtFunc
and should be used in future.
abstExtFunc :: (a -> b) -> AbstExt a -> AbstExt bSource
The function abstExtFunc
extends a function in order to process absent extended values. If the input is ("bottom"), the output will also be ("bottom").