Class: SPARQL::Algebra::Operator::StrDT

Inherits:
Operator::Binary
  • Object
show all
Includes:
Evaluatable
Defined in:
lib/sparql/algebra/operator/strdt.rb

Overview

The SPARQL strdt operator.

[121] BuiltInCall ::= ... | 'STRDT' '(' Expression ',' Expression ')'

Examples:

SPARQL Grammar

PREFIX : <http://example.org/>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
SELECT ?s (STRDT(?str,xsd:string) AS ?str1) WHERE {
  ?s :str ?str
  FILTER(LANGMATCHES(LANG(?str), "en"))
}

SSE

(prefix
 ((: <http://example.org/>) (xsd: <http://www.w3.org/2001/XMLSchema#>))
  (project (?s ?str1)
    (extend ((?str1 (strdt ?str xsd:string)))
      (filter (langMatches (lang ?str) "en")
        (bgp (triple ?s :str ?str))))))

See Also:

Constant Summary collapse

NAME = 
:strdt

Instance Method Summary collapse

Methods included from Evaluatable

#evaluate, #memoize, #replace_aggregate!, #replace_vars!

Instance Method Details

#apply(value, datatypeIRI, **options) ⇒ RDF::Literal

Constructs a literal with lexical form and type as specified by the arguments.

Parameters:

  • value (RDF::Literal) —

    a literal

  • datatypeIRI (RDF::URI) —

    datatype

Returns:

  • (RDF::Literal) —

    a datatyped literal

Raises:

  • (TypeError)

See Also:



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# File 'lib/sparql/algebra/operator/strdt.rb', line 39

def apply(value, datatypeIRI, **options)
  raise TypeError, "Literal #{value.inspect} is not simple" unless value.simple?
  RDF::Literal.new(value.to_s, datatype: datatypeIRI)
end

#to_sparql(**options) ⇒ String

Returns a partial SPARQL grammar for this operator.

Returns:

  • (String) 


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# File 'lib/sparql/algebra/operator/strdt.rb', line 49

def to_sparql(**options)
  "STRDT(" + operands.to_sparql(delimiter: ', ', **options) + ")"
end