Class: SPARQL::Algebra::Operator::UUID

Inherits:
Nullary show all
Includes:
Evaluatable
Defined in:
lib/sparql/algebra/operator/uuid.rb

Overview

The SPARQL uuid function.

[121] BuiltInCall ::= … | ‘UUID’ NIL

Examples:

SPARQL Grammar

PREFIX : <http://example.org/>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
ASK {
  BIND(UUID() AS ?u1)
  BIND(UUID() AS ?u2)
  FILTER(?u1 != ?u2)
}

SSE

(prefix
 ((: <http://example.org/>) (xsd: <http://www.w3.org/2001/XMLSchema#>))
 (ask
  (filter (!= ?u1 ?u2)
   (extend ((?u1 (uuid)) (?u2 (uuid)))
    (bgp)))))

See Also:

Constant Summary collapse

NAME = 
:uuid

Constants inherited from Nullary

Nullary::ARITY

Constants inherited from SPARQL::Algebra::Operator

ARITY, IsURI, URI

Constants included from Expression

Expression::PATTERN_PARENTS

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 Nullary

#initialize

Methods inherited from SPARQL::Algebra::Operator

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

Methods included from Expression

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

Constructor Details

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

Instance Method Details

#apply(**options) ⇒ RDF::URI

Return a fresh IRI from the UUID URN scheme. Each call of UUID() returns a different UUID. It must not be the “nil” UUID (all zeroes). The variant and version of the UUID is implementation dependent.

Returns:

  • (RDF::URI) 


37
38
39
 
# File 'lib/sparql/algebra/operator/uuid.rb', line 37

def apply(**options)
  RDF::URI("urn:uuid:#{SecureRandom.uuid}")
end

#to_sparql(**options) ⇒ String

Returns a partial SPARQL grammar for this operator.

Returns:

  • (String) 


46
47
48
 
# File 'lib/sparql/algebra/operator/uuid.rb', line 46

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