rdf-0.1.0.1: Representation and Incremental Processing of RDF Data

CopyrightTravis Whitaker 2016
LicenseMIT
Maintainerpi.boy.travis@gmail.com
StabilityProvisional
PortabilityPortable
Safe HaskellSafe
LanguageHaskell2010

Data.RDF.Types

Contents

Description

This module provides types for representing RDF data based on the abstract syntax described in RDF 1.1 Concepts and Abstract Syntax.

Synopsis

Graphs

data RDFGraph #

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.

Constructors

RDFGraph 

Fields

  • rdfLabel :: !(Maybe IRI)

    A named RDF graph includes an IRI.

  • rdfTriples :: [Triple]

    The constituent triples. A proper graph is a strict set of triples (i.e. no duplicate nodes or edges), but this guarantee cannot be made if the triples are to be processed incrementally in constant space. Programs using this type for interpreting RDF graphs should ignore any supernumerary triples in this list.

data Quad #

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

Constructors

Quad 

Fields

Instances

Eq Quad # 

Methods

(==) :: Quad -> Quad -> Bool #

(/=) :: Quad -> Quad -> Bool #

Ord Quad # 

Methods

compare :: Quad -> Quad -> Ordering #

(<) :: Quad -> Quad -> Bool #

(<=) :: Quad -> Quad -> Bool #

(>) :: Quad -> Quad -> Bool #

(>=) :: Quad -> Quad -> Bool #

max :: Quad -> Quad -> Quad #

min :: Quad -> Quad -> Quad #

Read Quad # 
Show Quad # 

Methods

showsPrec :: Int -> Quad -> ShowS #

show :: Quad -> String #

showList :: [Quad] -> ShowS #

Generic Quad # 

Associated Types

type Rep Quad :: * -> * #

Methods

from :: Quad -> Rep Quad x #

to :: Rep Quad x -> Quad #

NFData Quad # 

Methods

rnf :: Quad -> () #

type Rep Quad # 
type Rep Quad = D1 (MetaData "Quad" "Data.RDF.Internal" "rdf-0.1.0.1-3JHmIzKPsGx4JHlrY0brsh" False) (C1 (MetaCons "Quad" PrefixI True) ((:*:) (S1 (MetaSel (Just Symbol "quadTriple") NoSourceUnpackedness SourceStrict DecidedStrict) (Rec0 Triple)) (S1 (MetaSel (Just Symbol "quadGraph") NoSourceUnpackedness SourceStrict DecidedStrict) (Rec0 (Maybe IRI)))))

Triple Components

data Subject #

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"})

Instances

Eq Subject # 

Methods

(==) :: Subject -> Subject -> Bool #

(/=) :: Subject -> Subject -> Bool #

Ord Subject # 
Read Subject # 
Show Subject # 
IsString Subject #

This instance uses parseSubject and calls error if the literal is invalid. It is not clear exactly when fromString is evaluated so this error is difficult to explictly catch. This can be solved by ensuring that your Subject literals are eagerly evaluated so any malformed literals can be caught immediately. It would be nicer if this happened at compile time.

Methods

fromString :: String -> Subject #

Generic Subject # 

Associated Types

type Rep Subject :: * -> * #

Methods

from :: Subject -> Rep Subject x #

to :: Rep Subject x -> Subject #

NFData Subject # 

Methods

rnf :: Subject -> () #

type Rep Subject # 
type Rep Subject = D1 (MetaData "Subject" "Data.RDF.Internal" "rdf-0.1.0.1-3JHmIzKPsGx4JHlrY0brsh" False) ((:+:) (C1 (MetaCons "IRISubject" PrefixI False) (S1 (MetaSel (Nothing Symbol) NoSourceUnpackedness SourceStrict DecidedStrict) (Rec0 IRI))) (C1 (MetaCons "BlankSubject" PrefixI False) (S1 (MetaSel (Nothing Symbol) NoSourceUnpackedness SourceStrict DecidedStrict) (Rec0 BlankNode))))

newtype Predicate #

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 (...)}

Constructors

Predicate 

Fields

Instances

Eq Predicate # 
Ord Predicate # 
Read Predicate # 
Show Predicate # 
IsString Predicate #

This instance uses parsePredicate and calls error if the literal is invalid. It is not clear exactly when fromString is evaluated so this error is difficult to explictly catch. This can be solved by ensuring that your Predicate literals are eagerly evaluated so any malformed literals can be caught immediately. It would be nicer if this happened at compile time.

Generic Predicate # 

Associated Types

type Rep Predicate :: * -> * #

NFData Predicate # 

Methods

rnf :: Predicate -> () #

type Rep Predicate # 
type Rep Predicate = D1 (MetaData "Predicate" "Data.RDF.Internal" "rdf-0.1.0.1-3JHmIzKPsGx4JHlrY0brsh" True) (C1 (MetaCons "Predicate" PrefixI True) (S1 (MetaSel (Just Symbol "unPredicate") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 IRI)))

data Object #

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})

Instances

Eq Object # 

Methods

(==) :: Object -> Object -> Bool #

(/=) :: Object -> Object -> Bool #

Ord Object # 
Read Object # 
Show Object # 
IsString Object #

This instance uses parseObject and calls error if the literal is invalid. It is not clear exactly when fromString is evaluated so this error is difficult to explictly catch. This can be solved by ensuring that your Object literals are eagerly evaluated so any malformed literals can be caught immediately. It would be nicer if this happened at compile time.

Methods

fromString :: String -> Object #

Generic Object # 

Associated Types

type Rep Object :: * -> * #

Methods

from :: Object -> Rep Object x #

to :: Rep Object x -> Object #

NFData Object # 

Methods

rnf :: Object -> () #

type Rep Object # 

Terms

newtype BlankNode #

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"}

Constructors

BlankNode 

Fields

Instances

Eq BlankNode # 
Ord BlankNode # 
Read BlankNode # 
Show BlankNode # 
IsString BlankNode #

This instance uses parseBlankNode and calls error if the literal is invalid. It is not clear exactly when fromString is evaluated so this error is difficult to explictly catch. This can be solved by ensuring that your BlankNode literals are eagerly evaluated so any malformed literals can be caught immediately. It would be nicer if this happened at compile time.

Generic BlankNode # 

Associated Types

type Rep BlankNode :: * -> * #

NFData BlankNode # 

Methods

rnf :: BlankNode -> () #

type Rep BlankNode # 
type Rep BlankNode = D1 (MetaData "BlankNode" "Data.RDF.Internal" "rdf-0.1.0.1-3JHmIzKPsGx4JHlrY0brsh" True) (C1 (MetaCons "BlankNode" PrefixI True) (S1 (MetaSel (Just Symbol "unBlankNode") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Text)))

data Literal #

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 (...)}

Constructors

Literal 

Instances

Eq Literal # 

Methods

(==) :: Literal -> Literal -> Bool #

(/=) :: Literal -> Literal -> Bool #

Ord Literal # 
Read Literal # 
Show Literal # 
IsString Literal #

This instance uses parseLiteral and calls error if the literal is invalid. It is not clear exactly when fromString is evaluated so this error is difficult to explictly catch. This can be solved by ensuring that your Literal literals are eagerly evaluated so any malformed literals can be caught immediately. It would be nicer if this happened at compile time.

Methods

fromString :: String -> Literal #

Generic Literal # 

Associated Types

type Rep Literal :: * -> * #

Methods

from :: Literal -> Rep Literal x #

to :: Rep Literal x -> Literal #

NFData Literal # 

Methods

rnf :: Literal -> () #

type Rep Literal # 
type Rep Literal = D1 (MetaData "Literal" "Data.RDF.Internal" "rdf-0.1.0.1-3JHmIzKPsGx4JHlrY0brsh" False) (C1 (MetaCons "Literal" PrefixI True) ((:*:) (S1 (MetaSel (Just Symbol "litString") NoSourceUnpackedness SourceStrict DecidedStrict) (Rec0 Text)) (S1 (MetaSel (Just Symbol "litType") NoSourceUnpackedness SourceStrict DecidedStrict) (Rec0 LiteralType))))

data LiteralType #

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.

IRIs

data IRI #

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
    }

Constructors

IRI 

Fields

Instances

Eq IRI # 

Methods

(==) :: IRI -> IRI -> Bool #

(/=) :: IRI -> IRI -> Bool #

Ord IRI # 

Methods

compare :: IRI -> IRI -> Ordering #

(<) :: IRI -> IRI -> Bool #

(<=) :: IRI -> IRI -> Bool #

(>) :: IRI -> IRI -> Bool #

(>=) :: IRI -> IRI -> Bool #

max :: IRI -> IRI -> IRI #

min :: IRI -> IRI -> IRI #

Read IRI # 
Show IRI # 

Methods

showsPrec :: Int -> IRI -> ShowS #

show :: IRI -> String #

showList :: [IRI] -> ShowS #

IsString IRI #

This instance uses parseIRI and calls error if the literal is invalid. It is not clear exactly when fromString is evaluated so this error is difficult to explictly catch. This can be solved by ensuring that your IRI literals are eagerly evaluated so any malformed literals can be caught immediately. It would be nicer if this happened at compile time.

Methods

fromString :: String -> IRI #

Generic IRI # 

Associated Types

type Rep IRI :: * -> * #

Methods

from :: IRI -> Rep IRI x #

to :: Rep IRI x -> IRI #

NFData IRI # 

Methods

rnf :: IRI -> () #

type Rep IRI # 

data IRIAuth #

An IRI Authority, as described by RFC 3987.

Constructors

IRIAuth 

Fields