class SPARQL::Algebra::Operator::Count
The SPARQL
`count` set function.
@example
(prefix ((: <http://www.example.org>)) (project (?C) (extend ((?C ??.0)) (group () ((??.0 (count ?O))) (bgp (triple ?S ?P ?O))))))
Constants
- NAME
Public Instance Methods
apply(enum, **options)
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Count
is a SPARQL
set function which counts the number of times a given expression has a bound, and non-error value within the aggregate group.
@param [Enumerable<Array<RDF::Term>>] enum
enum of evaluated operand
@return [RDF::Literal::Integer] The number of non-error terms in the multiset
# File lib/sparql/algebra/operator/count.rb, line 25 def apply(enum, **options) RDF::Literal(enum.length) end