| Safe Haskell | Safe-Infered |
|---|
Test.Feat
Contents
- data Enumerate a = Enumerate {}
- class Typeable a => Enumerable a where
- nullary :: a -> Constructor a
- unary :: Enumerable a => (a -> b) -> Constructor b
- funcurry :: (a -> b -> c) -> FreePair a b -> c
- consts :: [Constructor a] -> Enumerate a
- deriveEnumerable :: Name -> Q [Dec]
- newtype FreePair a b = Free {
- free :: (a, b)
- optimised :: Enumerable a => Enumerate a
- index :: Enumerate a -> Integer -> a
- values :: Enumerable a => [(Integer, [a])]
- bounded :: Enumerable a => Integer -> [(Integer, [a])]
- uniform :: Enumerable a => Int -> Gen a
- ioAll :: Enumerable a => (a -> IO ()) -> IO ()
- ioBounded :: Enumerable a => Integer -> (a -> IO ()) -> IO ()
Documentation
A functional enumeration of type t is a partition of t into finite numbered sets called Parts. The number that identifies each part is called the cost of the values in that part.
Constructors
| Enumerate | |
The type class
class Typeable a => Enumerable a whereSource
A class of functionally enumerable types
Methods
enumerate :: Enumerate aSource
This is the interface for defining an instance. Memoisation needs to
be ensured e.g. using mempay but sharing is handled automatically by
the default implementation of shared.
Version of enumerate that ensures it is shared between all accessing functions. Should alwasy be used when combining enumerations. Should typically be left to default behaviour.
Instances
nullary :: a -> Constructor aSource
For nullary constructors such as True and [].
unary :: Enumerable a => (a -> b) -> Constructor bSource
For any non-nullary constructor. Apply funcurry until the type of
the result is unary (i.e. n-1 times where n is the number of fields
of the constructor).
funcurry :: (a -> b -> c) -> FreePair a b -> cSource
Uncurry a function (typically a constructor) to a function on free pairs.
consts :: [Constructor a] -> Enumerate aSource
Produces the enumeration of a type given the enumerators for each of its
constructors. The result of unary should typically not be used
directly in an instance even if it only has one constructor. So you
should apply consts even in that case.
deriveEnumerable :: Name -> Q [Dec]Source
Derive an instance of Enumberable with Template Haskell.
A free pair constructor. The cost of constructing a free pair is equal to the sum of the costs of its components.
Instances
| Typeable2 FreePair | |
| (Show a, Show b) => Show (FreePair a b) | |
| (Enumerable a, Enumerable b) => Enumerable (FreePair a b) |
Accessing data
optimised :: Enumerable a => Enumerate aSource
An optimised version of enumerate. Used by all
library functions that access enumerated values (but not
by combining functions). Library functions should ensure that
optimised is not reevaluated.
index :: Enumerate a -> Integer -> aSource
Mainly as a proof of concept we can use the isomorphism between natural numbers and (Part,Index) pairs to index into a type May not terminate for finite types. Might be slow the first time it is used with a specific enumeration because cardinalities need to be calculated. The computation complexity after cardinalities are computed is a polynomial of the size of the resulting value.
values :: Enumerable a => [(Integer, [a])]Source
All values of the enumeration by increasing cost (which is the number of constructors for most types). Also contains the cardinality of each list.
bounded :: Enumerable a => Integer -> [(Integer, [a])]Source
A version of vales that has a limited number of values in each inner list. If the list corresponds to a Part which is larger than the bound it evenly intersperses the values across the enumeration of the Part.
uniform :: Enumerable a => Int -> Gen aSource
Compatability with QuickCheck. Distribution is uniform generator over
values bounded by the given size. Typical use: sized uniform.