Module: RDF::Oxigraph::SPARQL

Defined in:
lib/rdf/oxigraph/sparql.rb

Defined Under Namespace

Classes: Client

Class Method Summary collapse

Class Method Details

.results(tagged) ⇒ Object

Convert a native Store#query tagged result into RDF.rb-native objects:

["boolean", bool]                  -> true / false
["solutions", vars, rows]          -> RDF::Query::Solutions
["graph", triples]                 -> RDF::Graph


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# File 'lib/rdf/oxigraph/sparql.rb', line 10

def results(tagged)
  case tagged[0]
  when "boolean"
    tagged[1]
  when "solutions"
    _, vars, rows = tagged
    solutions = RDF::Query::Solutions.new
    rows.each do |row|
      bindings = {}
      vars.each_with_index do |var, i|
        term = Conversion.deserialize(row[i])
        bindings[var.to_sym] = term unless term.nil?
      end
      solutions << RDF::Query::Solution.new(bindings)
    end
    solutions
  when "graph"
    graph = RDF::Graph.new
    tagged[1].each do |triple|
      graph << RDF::Statement.new(
        Conversion.deserialize(triple[0]),
        Conversion.deserialize(triple[1]),
        Conversion.deserialize(triple[2])
      )
    end
    graph
  else
    raise ArgumentError, "unknown query result kind: #{tagged[0].inspect}"
  end
end