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| Data.Relation.MapFromPairs | | Portability | portable | | Stability | experimental | | Maintainer | joost.visser@di.uminho.pt |
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| Description |
| An implementation of labeled relations as map from pairs to values.
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| Synopsis |
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| type LRel a b c = FiniteMap (a, b) c | | | rel :: (Ord a, Ord b) => (c -> Bool) -> LRel a b c -> Rel a b | | | lrel :: (Ord a, Ord b) => c -> Rel a b -> LRel a b c | | | entities :: Ord a => LRel a a c -> Set a | | | extremal :: Ord a => b -> (b -> b -> b) -> (b -> b -> b) -> LRel a a b -> LRel a a b | | | reach :: Ord a => LRel a a Bool -> LRel a a Bool | | | leastcost :: (Num cost, Ord cost, Ord a) => cost -> LRel a a cost -> LRel a a cost | | | bottleneck :: (Ord height, Num height, Ord a) => LRel a a height -> LRel a a height | | | leastcost' :: (Num cost, Ord cost, Bounded cost, Ord a) => LRel a a cost -> LRel a a cost |
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| Representation |
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| type LRel a b c = FiniteMap (a, b) c |
| The type of labeled releations. |
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| rel |
| :: (Ord a, Ord b) | | | => (c -> Bool) | Predicate on labels. | | -> LRel a b c | | | -> Rel a b | | | Convert labeled relation to one without labels. The first argument
is a predicate that determines, based on the label, which pairs are
to be included in the result relation. |
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| lrel |
| :: (Ord a, Ord b) | | | => c | Initialization label | | -> Rel a b | | | -> LRel a b c | | | Convert relation to a labeled one. The first argument is the
label with which all pairs in the result relation will be labeled. |
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| entities :: Ord a => LRel a a c -> Set a |
| Carrier set. |
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| Extremal paths. |
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| extremal |
| :: Ord a | | | => b | Zero of multiplication. | | -> (b -> b -> b) | Multiplication. | | -> (b -> b -> b) | Addition. | | -> LRel a a b | | | -> LRel a a b | | | Generic extremal path algorithm, based on Roland Backhouse's
lecture notes, page 192 (draft version). |
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| reach :: Ord a => LRel a a Bool -> LRel a a Bool |
| Reachability. This is transitive closure following Roy-Warshall. |
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| leastcost |
| :: (Num cost, Ord cost, Ord a) | | | => cost | Maximum bound. | | -> LRel a a cost | Cost labels must be non-negative. | | -> LRel a a cost | | | Least cost, or shortest path. |
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| bottleneck |
| :: (Ord height, Num height, Ord a) | | | => LRel a a height | Height labels must be non-negative. | | -> LRel a a height | | | Bottle neck. |
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| leastcost' :: (Num cost, Ord cost, Bounded cost, Ord a) => LRel a a cost -> LRel a a cost |
| Least cost, or shortest path. DOES NOT WORK, because it relies on
maxBound from the Bounded class, leading to erroneous arithmetic. |
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| Produced by Haddock version 0.6 |
