Class: SPARQL::Algebra::Operator::Not

Inherits:
Unary show all
Includes:
Evaluatable
Defined in:
lib/sparql/algebra/operator/not.rb

Overview

The SPARQL logical not operator.

Examples:

(! ?x ?y)
(not ?x ?y)

See Also:

Constant Summary

NAME =
[:not, :!']

Constants inherited from Unary

Unary::ARITY

Constants inherited from SPARQL::Algebra::Operator

ARITY

Instance Attribute Summary

Attributes inherited from SPARQL::Algebra::Operator

#operands, #options

Instance Method Summary (collapse)

Methods included from Evaluatable

#evaluate, #memoize

Methods inherited from Unary

#initialize

Methods inherited from SPARQL::Algebra::Operator

arity, base_uri, #base_uri, base_uri=, #boolean, #constant?, #eql?, #evaluatable?, evaluate, #executable?, for, #initialize, #inspect, #operand, #optimize, prefixes, #prefixes, prefixes=, #to_sse, #to_sxp, #variable?

Methods included from Expression

cast, #constant?, #evaluate, for, new, open, #optimize, parse, #to_sse, #variable?

Constructor Details

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

Instance Method Details

- (RDF::Literal::Boolean) apply(operand)

Returns the logical NOT (inverse) of the operand.

Note that this operator operates on the effective boolean value (EBV) of its operand.

Parameters:

  • operand (RDF::Literal::Boolean)

    the operand

Returns:

  • (RDF::Literal::Boolean)

    true or false

Raises:

  • (TypeError)

    if the operand could not be coerced to a boolean literal



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# File 'lib/sparql/algebra/operator/not.rb', line 26

def apply(operand)
  case bool = boolean(operand)
    when RDF::Literal::Boolean
      RDF::Literal(bool.false?)
    else super
  end
end