Class: SPARQL::Algebra::Operator::Desc

Inherits:

Operator::Asc

• Object
• Operator::Asc
• SPARQL::Algebra::Operator::Desc

Defined in:

lib/sparql/algebra/operator/desc.rb

Overview

The SPARQL descending sort operator.

[24] OrderCondition ::= ( ( 'ASC' | 'DESC' ) BrackettedExpression ) | ( Constraint | Var )

Examples:

SPARQL Grammar

PREFIX foaf:    <http://xmlns.com/foaf/0.1/>
SELECT ?name
WHERE { ?x foaf:name ?name }
ORDER BY DESC(?name)

SSE

(prefix ((foaf: <http://xmlns.com/foaf/0.1/>))
  (project (?name)
    (order ((desc ?name))
      (bgp (triple ?x foaf:name ?name)))))

See Also:

• https://www.w3.org/TR/sparql11-query/#modOrderBy

Constant Summary

NAME =

:desc

Instance Method Summary

• #to_sparql(**options) ⇒ String

  Returns a partial SPARQL grammar for this operator.

Instance Method Details

#to_sparql(**options) ⇒ String

Returns a partial SPARQL grammar for this operator.

Provides order to descendant query.

Returns:

• (String)

# File 'lib/sparql/algebra/operator/desc.rb', line 31

def to_sparql(**options)
  "DESC(#{operands.last.to_sparql(**options)})"
end