| Copyright | Copyright (c) , Patrick Perry <[email protected]> |
|---|---|
| License | BSD3 |
| Maintainer | Patrick Perry <[email protected]> |
| Stability | experimental |
| Safe Haskell | None |
| Language | Haskell98 |
Data.Choose
Contents
Description
Immutable combinations.
- data Choose
- choose :: Int -> Int -> Choose
- listChoose :: Int -> Int -> [Int] -> Choose
- at :: Choose -> Int -> Int
- unsafeAt :: Choose -> Int -> Int
- possible :: Choose -> Int
- size :: Choose -> Int
- elems :: Choose -> [Int]
- complement :: Choose -> Choose
- complElems :: Choose -> [Int]
- next :: Choose -> Maybe Choose
- prev :: Choose -> Maybe Choose
Combinations
The immutable combination data type. A way of representing k
unordered outcomes from n possiblities. The possibilites are
represented as the indices 0, ..., n-1, and the outcomes are
given as a subset of size k. The subset is stored with the indices
in ascending order.
Creating combinations
choose :: Int -> Int -> Choose Source
choose n k returns the first combination of k outcomes from n
possibilites, namely the subset { 0, ..., k-1 }.
listChoose :: Int -> Int -> [Int] -> Choose Source
Construct a combination from a list of elements.
listChoose n k is creates a combination of k outcomes from n
possibilities initialized to have the ith element equal to is !! i.
For the combination to be valid, the elements must all be unique, they
must be in sorted order, and they all must be in the range 0 .. n-1.
Accessing combination elements
at :: Choose -> Int -> Int Source
at c i gets the value of the ith element of the combination
c. The index i must be in the range 0..(k-1), where k is the
size of the combination.
Combination properties
Combination functions
complement :: Choose -> Choose Source
Get the inverse of a combination
complElems :: Choose -> [Int] Source
Get a list of the elements in the complement of a combination.
If the combination is a subset of k outcomes from n possibilities, then
the returned list will be sorted and of length n-k.