This is the RSP-QL extension of the SPIN modeling vocabulary, which enables RSP-QL queries (see link) to be represented as RDF. In combination with the provided API queries can be converted to and from RDF, and queries can be parameterized into reusable query templates that support parameter constraints.
Below is a sample query demonstrating how an RSP-QL query would be represented as RDF:
# Based on sample query 1 (https://github.com/streamreasoning/RSP-QL)
# Get the number of taxi rides that exceeded ?limit miles in the last hour.
PREFIX : <http://debs2015.org/streams/>
PREFIX onto: <http://debs2015.org/onto#>
REGISTER STREAM ?outputStream AS
SELECT ISTREAM (COUNT(?ride) AS ?rideCount)
FROM NAMED WINDOW :wind ON ?inputStream [RANGE PT1H STEP PT1H]
WHERE
{ WINDOW :win
{ ?ride onto:distance ?distance
FILTER ( ?distance > ?limit )
}
}
Using the RSP-SPIN modeling vocabulary it would be represented in RDF as:
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
@prefix sp: <http://spinrdf.org/sp#> .
@prefix rsp: <http://w3id.org/rsp/spin#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
@prefix sp: <http://spinrdf.org/sp#> .
@prefix rsp: <http://w3id.org/rsp/spin#> .
<http://example.org/query/1>
a sp:Select ;
rsp:hasOutputStream [ sp:varName "outputStream" ] ;
rsp:hasOutputStreamOperator rsp:Istream
sp:resultVariables ( _:b0 ) ;
rsp:fromNamedWindow [ a rsp:LogicalWindow ;
rsp:logicalRange "PT1H"^^xsd:duration ;
rsp:logicalStep "PT1H"^^xsd:duration ;
rsp:streamUri [ sp:varName "inputStream" ] ;
rsp:windowUri <http://debs2015.org/streams/wind>
] ;
sp:where ( _:b1 )
.
_:b0 sp:expression [ a sp:Count ;
sp:expression [ sp:varName "ride" ]
] ;
sp:varName "rideCount" .
_:b1 a rsp:NamedWindow ;
sp:elements ( _:b3 _:b2 ) ;
rsp:windowNameNode <http://debs2015.org/streams/win> .
_:b2 a sp:Filter ;
sp:expression [ a sp:gt ;
sp:arg1 [ sp:varName "distance" ] ;
sp:arg2 [ sp:varName "limit" ]
] .
_:b3 sp:subject [ sp:varName "ride" ] ;
sp:predicate <http://debs2015.org/onto#distance> ;
sp:object [ sp:varName "distance" ] .
Now, let's use define a template over this query allowing us to specify the limit variable of the query as an integer with a default value, and require that the inputStream and outputStream are provided as URIs.
@prefix : <http://debs2015.org/streams/> .
@prefix spin: <http://spinrdf.org/spin#> .
@prefix arg: <http://spinrdf.org/arg#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix sp: <http://spinrdf.org/sp#> .
@prefix spl: <http://spinrdf.org/spl#> .
:t1 a spin:Template ;
spin:body <http://example.org/query/1> ;
spin:constraint [ a spl:Argument ;
rdfs:comment "Get the taxi rides that exceeded this limit in the last hour." ;
spl:defaultValue 2 ;
spl:optional true ;
spl:predicate arg:limit ;
spl:valueType xsd:integer
] ;
spin:constraint [ a spl:Argument ;
rdfs:comment "Represents the URI identifier of the input stream." ;
spl:optional false ;
spl:predicate arg:inputStream ;
spl:valueType rdfs:Resource
] ;
spin:constraint [ a spl:Argument ;
rdfs:comment "Represents the URI identifier of the resulting stream." ;
spl:optional false ;
spl:predicate arg:outputStream ;
spl:valueType rdfs:Resource
] .
See http://spinrdf.org/spin.html for details about the SPIN Modeling Vocabulary.