Swish.GraphClass

This module defines a Labelled Directed Graph and Label classes, and the Arc datatype.

Documentation

class LDGraph lg lb where

Labelled Directed Graph class.

Minimum required implementation: emptyGraph, setArcs, and getArcs.

Minimal complete definition

emptyGraph, setArcs, getArcs

Methods

emptyGraph :: lg lb

Create the empty graph.

setArcs :: lg lb -> ArcSet lb -> lg lb

Replace the existing arcs in the graph.

getArcs :: lg lb -> ArcSet lb

Extract all the arcs from a graph

extract :: Ord lb => Selector lb -> lg lb -> lg lb

Extract those arcs that match the given Selector.

addGraphs :: Ord lb => lg lb -> lg lb -> lg lb

Add the two graphs

delete

Arguments

:: Ord lb

=> lg lb

g1

-> lg lb

g2

-> lg lb

g2 - g1 -> g3

Remove those arcs in the first graph from the second graph

labels :: Ord lb => lg lb -> Set lb

Enumerate the distinct labels contained in a graph; that is, any label that appears in the subject, predicate or object position of an Arc.

nodes :: Ord lb => lg lb -> Set lb

Enumerate the distinct nodes contained in a graph; that is, any label that appears in the subject or object position of an Arc.

update :: (ArcSet lb -> ArcSet lb) -> lg lb -> lg lb

Update the arcs in a graph using a supplied function.

Instances

Label lb => LDGraph GraphMem lb

Label lb => LDGraph NSGraph lb

class (Ord lb, Show lb) => Label lb where

Label class.

A label may have a fixed binding, which means that the label identifies (is) a particular graph node, and different such labels are always distinct nodes. Alternatively, a label may be unbound (variable), which means that it is a placeholder for an unknown node label. Unbound node labels are used as graph-local identifiers for indicating when the same node appears in several arcs.

For the purposes of graph-isomorphism testing, fixed labels are matched when they are the same. Variable labels may be matched with any other variable label. Our definition of isomorphism (for RDF graphs) does not match variable labels with fixed labels.

Methods

labelIsVar :: lb -> Bool

Does this node have a variable binding?

labelHash :: Int -> lb -> Int

Calculate the hash of the label using the supplied seed.

getLocal :: lb -> String

Extract the local id from a variable node.

makeLabel :: String -> lb

Make a label value from a local id.

Instances

Label LabelMem

Label RDFLabel

Label lb => Label (ScopedLabel lb)

data Arc lb

Arc type.

Prior to 0.7.0.0 you could also use asubj, apred and aobj to access the elements of the arc.

Constructors

Arc

Fields

arcSubj :: lb

The subject of the arc.

arcPred :: lb

The predicate (property) of the arc.

arcObj :: lb

The object of the arc.

Instances

Functor Arc

Foldable Arc

Traversable Arc

Eq lb => Eq (Arc lb)

Ord lb => Ord (Arc lb)

Show lb => Show (Arc lb)

Hashable lb => Hashable (Arc lb)

type ArcSet lb = Set (Arc lb)

A set - or graph - of arcs.

type Selector lb = Arc lb -> Bool

Identify arcs.

arc

Arguments

:: lb

The subject of the arc.

-> lb

The predicate of the arc.

-> lb

The object of the arc.

-> Arc lb

Create an arc.

arcToTriple :: Arc lb -> (lb, lb, lb)

Convert an Arc into a tuple.

arcFromTriple :: (lb, lb, lb) -> Arc lb

Create an Arc from a tuple.

hasLabel :: Eq lb => lb -> Arc lb -> Bool

Does the arc contain the label in any position (subject, predicate, or object)?

arcLabels :: Arc lb -> [lb]

Return all the labels in an arc.

getComponents :: (Ord a, Ord b) => (a -> [b]) -> Set a -> Set b

Extract components from a set.