Class: SPARQL::Algebra::Operator::Timezone

Inherits:
Unary show all
Includes:
Evaluatable
Defined in:
vendor/bundler/ruby/2.5.0/bundler/gems/sparql-bb59900f675b/lib/sparql/algebra/operator/timezone.rb

Overview

The SPARQL logical timezone operator.

Returns the timezone part of arg as an xsd:dayTimeDuration. Raises an error if there is no timezone.

Examples:

(prefix ((: <http://example.org/>))
  (project (?s ?x)
    (extend ((?x (timezone ?date)))
      (bgp (triple ?s :date ?date)))))

See Also:

Constant Summary

NAME =
:timezone

Constants inherited from Unary

Unary::ARITY

Constants inherited from SPARQL::Algebra::Operator

ARITY, IsURI, URI

Instance Attribute Summary

Attributes inherited from SPARQL::Algebra::Operator

#operands

Instance Method Summary collapse

Methods included from Evaluatable

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

Methods inherited from Unary

#initialize

Methods inherited from SPARQL::Algebra::Operator

#aggregate?, arity, #base_uri, base_uri, base_uri=, #boolean, #constant?, #each_descendant, #eql?, #evaluatable?, evaluate, #executable?, #first_ancestor, for, #initialize, #inspect, #ndvars, #node?, #operand, #optimize, #parent, #parent=, prefixes, #prefixes, prefixes=, #rewrite, #to_binary, #to_sxp, #to_sxp_bin, #validate!, #variable?, #vars

Methods included from Expression

cast, #constant?, #evaluate, extension, extensions, for, #invalid?, new, #node?, open, #optimize, parse, register_extension, #to_sxp_bin, #valid?, #validate!, #variable?

Constructor Details

This class inherits a constructor from SPARQL::Algebra::Operator::Unary

Instance Method Details

#apply(operand) ⇒ RDF::Literal

Returns the timezone part of arg as an xsd:dayTimeDuration. Raises an error if there is no timezone.

This function corresponds to fn:timezone-from-dateTime except for the treatment of literals with no timezone.

Parameters:

Returns:

Raises:

  • (TypeError)

    if the operand is not a simple literal



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# File 'vendor/bundler/ruby/2.5.0/bundler/gems/sparql-bb59900f675b/lib/sparql/algebra/operator/timezone.rb', line 29

def apply(operand)
  raise TypeError, "expected an RDF::Literal::DateTime, but got #{operand.inspect}" unless operand.is_a?(RDF::Literal::DateTime)
  raise TypeError, "literal has no timezone" unless res = operand.timezone
  res
end