A contiguous RDF graph with optional label. Note that a contiguous graph within an RDF data set will not appear as a single contiguous graph to this library if the graph's constituent triples are not contiguous in the original data set. This strategy allows for incremental processing of RDF data in constant space.

An RDF quad, i.e. a triple belonging to a named graph.

An RDF triple.

An RDF subject, i.e. either an IRI or a BlankNode.

This type has an IsString instance, allowing string literals to be interpreted as Subjects with -XOverloadedStrings, like so:

>>> "<http://example.com> :: Subject
IRISubject (IRI (...))
>>> "_:some-node" :: Subject
BlankSubject (BlankNode {unBlankNode = "some-node"})

An RDF predicate.

This type has an IsString instance, allowing string literals to be interpreted as Predicates with -XOverloadedStrings, like so:

>>> "<http://example.com>" :: Predicate
Predicate {unPredicate = IRI (...)}

An RDF object, i.e. either an IRI, a Literal, or a BlankNode.

This type has an IsString instance, allowing string literals to be interpreted as Objects with -XOverloadedStrings, like so:

>>> "<http://example.com>" :: Object
IRIObject (IRI (...))
>>> "_:some-node" :: Object
BlankObject (BlankNode {unBlankNode = "some-node"})
>>> "computer" :: Object
LiteralObject (Literal {litString = "computer", litType = LiteralUntyped})

The precedence for literal interpretation is IRI > BlankNode > Literal. To force a literal that is also a valid blank node label or IRI to be interpreted as a LiteralObject, wrap it in an extra set of double quotes:

>>> "\"_:some-node\"" :: Object
LiteralObject (Literal {litString = "_:some-node", litType = LiteralUntyped})

A blank node with its local label, without the preceeding "_:". Other programs processing RDF are permitted to discard these node labels, i.e. all blank node labels are local to a specific representation of an RDF data set.

This type has an IsString instance, allowing string literals to be interpreted as BlankNodes with -XOverloadedStrings, like so:

>>> "_:some-node" :: BlankNode
BlankNode {unBlankNode = "some-node"}

An RDF literal. As stipulated by the RDF standard, the litType is merely metadata; all RDF processing programs must try to handle literals that are ill-typed.

This type has an IsString instance, allowing string literals to be interpreted as Literals with -XOverloadedStrings, like so:

>>> "computer" :: Literal
Literal {litString = "computer", litType = LiteralUntyped}

For untyped literals the extra double quotes are not required. They are required for typed literals:

>>> "\"computer\"@en" :: Literal
Literal {litString = "computer", litType = LiteralLangType "en"}

>>> "\"computer\"^^<http://computer.machine/machine>" :: Literal
Literal { litString = "computer", litType = LiteralIRIType (...)}

An RDF literal type. As stipulated by the RDF standard, this is merely metadata; all RDF processing programs must try to handle literals that are ill-typed.

An Internationalized Resource Identifier. This library preferentially follows RFC 3987 over the RDF 1.1 specification, as the two standards disagree about precisely what constitutes an IRI. A notable exception is the handling of IRI fragments; this library follows the RDF 1.1 specification, allowing IRI fragments to occur in absolute IRIs, even though this is expressly prohibited by RFC 3987.

Unlike the network-uri package's behavior with URI fields, this library does not include the sentinel tokens in the parsed fields. For example, when parsing http://example.com, network-uri will provide the string http: as the scheme, while this library will provide http as the scheme.

This type has an IsString instnace, allowing string literals to be interpreted as IRIs with -XOverloadedStrings, like so:

>>> "http://example.com" :: IRI
IRI { iriScheme = "http"
    , iriAuth = Just (IRIAuth { iriUser = Nothing
                              , iriHost = "example.com"
                              , iriPort = Nothing
                              })
    , iriPath = ""
    , iriQuery = Nothing
    , iriFragment = Nothing
    }

An IRI Authority, as described by RFC 3987.