grafter-2.rdf.protocols
added in 0.12.1
Abstract functions for interacting with RDF & RDF backends, such as
RDF4j.
add
(add target triples)(add target graph triples)(add target graph format triple-stream)(add target graph base-uri format triple-stream)
Adds a sequence of statements to the specified datasink. Supports
all the same targets as add-statement.
Takes an optional string/URI to use as a graph.
Depending on the target, this function will also write any prefixes
associated with the rdf-writer to the target.
Returns target.
add-batched
(add-batched target triples)(add-batched target graph-or-triples triples-or-batch-size)(add-batched target graph triples batch-size)
Adds a collection of statements to a repository in batches. The batch size is optional and default-batch-size
will be used if not specified. Some repository implementations cache added statements in memory until explicitly
flushed which can cause out-of-memory errors if a large number of statements are added through add. Spliting the
input sequence into batches limits the number of cached statements and therefore can reduce memory pressure.
add-statement
(add-statement target statement)(add-statement target graph statement)
Add an RDF statement to the target datasink. Datasinks must
implement `grafter-2.rdf.protocols/ITripleWriteable`.
Datasinks include RDF4j RDF repositories, connections and anything
built by rdf-writer.
Takes an optional string/URI to use as a graph.
blank-node?
multimethod
Predicate function that tests whether the supplied value is
considered to be a blank node type.
delete
(delete target quads)(delete target graph triples)
Deletes a sequence of statements from the specified repository.
Takes an optional string/URI to use as a graph.
Returns target.
delete-batched
(delete-batched target quads)(delete-batched target graph-or-quads triples-or-batch-size)(delete-batched target graph triples batch-size)
Deletes a collection of statements from a repository in batches. The batch size is optional and default-batch-size
will be used if not specified.
IDatatypeURI
protocol
members
datatype-uri
(datatype-uri this)
Returns the RDF literals datatype URI as a java.net.URI.
IGrafterRDFType
protocol
This protocol coerces a backend RDF type, e.g. an RDF4j quad object
into an equivalent Grafter RDF type. For example given an RDF4j
quad it will convert it into a Grafter Quad.
members
->grafter-type
(->grafter-type this)
Convert a backend RDF Type into a Native Type
IRawValue
protocol
members
raw-value
(raw-value this)
Returns the naked value of a literal. For native primitive
values e.g. a java.lang.Integer, this will return the supplied
value (like identity). However for more complex types such as
LangString's it will coerce the value into a more natural
primitive type.
IRDFString
protocol
members
lang
(lang this)
Return the strings language tag (as a clojure Keyword)
ISPARQLable
protocol
NOTE this protocol is intended for low-level access. End users
should use query instead.
Run an arbitrary SPARQL query. Works with `ASK`, `DESCRIBE`,
`CONSTRUCT` and `SELECT` queries.
You can call this on a Repository however if you do you may in some
cases cause a resource leak, for example if the sequence of results
isn't fully consumed.
To use this without leaking resources it is recommended that you
call `->connection` on your repository, inside a `with-open`; and
then consume all your results inside of a nested `doseq`/`dorun`/etc...
e.g.
````
(with-open [conn (->connection repo)]
(doseq [res (query conn "SELECT * WHERE { ?s ?p ?o .}")]
(println res)))
````members
query-dataset
(query-dataset this sparql-string model)
ISPARQLUpdateable
protocol
members
update!
(update! this sparql-string)
Issue a SPARQL Update statement against the repository
IStatement
protocol
members
context
(context statement)
predicate
(predicate statement)
subject
(subject statement)
ITransactable
protocol
Low level protocol for transactions support. Most users probably
want to use grafter-2.rdf.sesame/with-transaction
ITripleDeleteable
protocol
This protocol can be implemented by anything which you can delete
statements from. For example a SPARQL Update Endpoint.
members
delete-statement
(delete-statement this statement)(delete-statement this graph statement)
ITripleReadable
protocol
Use the higher level wrapper function statements if you just wish to read in some RDF.
This protocol exists for implementers to hook in additional sources of statements.
Takes a source of statements or triples and converts it into a seq
of triples.
A hash of options is passed to each implementation, they may be
ignored or handled depending on the circumstance.
members
to-statements
(to-statements this options)
ITripleWriteable
protocol
This protocol is implemented by anything which you can put
statements into.
language
(language s lang)
Create an RDF langauge string out of a value string and a given
language tag. Language tags should be keywords representing the
country code, e.g.
(language "Bonsoir" :fr)
literal
(literal val datatype-uri)
You can use this to declare an RDF typed literal value along with
its URI. Note that there are implicit coercions already defined for
many core clojure/java datatypes, so for common datatypes you
shounld't need this.
make-blank-node
(make-blank-node)(make-blank-node id)
Construct a new blank node. If 0-arity is used a blank node with a
new locally unique process id is used.
triple=
(triple= & quads)
Equality test for an RDF triple or quad, that checks whether the supplied RDF
statements are equal in terms of RDFs semantics i.e. two quads will be equal
regardless of their graph/context providing their subject, predicate and
objects are equal.
Like clojure.core/= this function can be applied to any number of statements.
triple?
(triple? t)
Predicate function to test if object is a valid RDF triple.