|
Data.Ranged.Boundaries | Portability | portable | Stability | experimental | Maintainer | paul@cogito.org.uk |
|
|
|
Description |
|
|
Synopsis |
|
|
|
Documentation |
|
class Ord a => DiscreteOrdered a where |
Distinguish between dense and sparse ordered types. A dense type is
one in which any two values v1 < v2 have a third value v3 such that
v1 < v3 < v2.
In theory the floating types are dense, although in practice they can only have
finitely many values. This class treats them as dense.
Tuples up to 4 members are declared as instances. Larger tuples may be added
if necessary.
This approach was suggested by Ben Rudiak-Gould on comp.lang.functional.
| | Methods | adjacent :: a -> a -> Bool | Two values x and y are adjacent if x < y and there does not
exist a third value between them. Always False for dense types.
|
| | Instances | DiscreteOrdered Bool | DiscreteOrdered Char | DiscreteOrdered Double | DiscreteOrdered Float | DiscreteOrdered Int | DiscreteOrdered Integer | DiscreteOrdered Ordering | (Ord a, DiscreteOrdered b) => DiscreteOrdered (a, b) | (Ord a, Ord b, DiscreteOrdered c) => DiscreteOrdered (a, b, c) | (Ord a, Ord b, Ord c, DiscreteOrdered d) => DiscreteOrdered (a, b, c, d) | Integral a => DiscreteOrdered (Ratio a) | Ord a => DiscreteOrdered [a] |
|
|
|
adjacent :: DiscreteOrdered a => a -> a -> Bool |
Two values x and y are adjacent if x < y and there does not
exist a third value between them. Always False for dense types.
|
|
enumAdjacent :: (Ord a, Enum a) => a -> a -> Bool |
Check adjacency for sparse enumerated types (i.e. where there
is no value between x and succ x). Use as the definition of
adjacent for most enumerated types.
|
|
boundedAdjacent :: (Ord a, Enum a) => a -> a -> Bool |
Check adjacency, allowing for case where x = maxBound. Use as the
definition of adjacent for bounded enumerated types such as Int and Char.
|
|
data Boundary a |
A Boundary is a division of an ordered type into values above
and below the boundary. No value can sit on a boundary.
Known bug: for Bounded types
This is incorrect because there are no possible values in
between the left and right sides of these inequalities.
| Constructors | BoundaryAbove a | The argument is the highest value below the boundary.
| BoundaryBelow a | The argument is the lowest value above the boundary.
| BoundaryAboveAll | The boundary above all values.
| BoundaryBelowAll | The boundary below all values.
|
| Instances | |
|
|
above :: Ord v => Boundary v -> v -> Bool |
True if the value is above the boundary, false otherwise.
|
|
(/>/) :: Ord v => v -> Boundary v -> Bool |
Same as above, but with the arguments reversed for more intuitive infix
usage.
|
|
Produced by Haddock version 0.8 |