Class: SPARQL::Algebra::Operator::IsNumeric

Inherits:
Unary show all
Includes:
Evaluatable
Defined in:
lib/sparql/algebra/operator/is_numeric.rb

Overview

The SPARQL isNumeric operator.

Note numeric denotes typed literals with datatypes xsd:integer, xsd:decimal, xsd:float, and xsd:double, not derived types.

Examples:

(prefix ((xsd: <http://www.w3.org/2001/XMLSchema#>)
         (: <http://example.org/things#>))
  (project (?x ?v)
    (filter (isNumeric ?v)
      (bgp (triple ?x :p ?v)))))

See Also:

Constant Summary collapse

NAME = 
:isnumeric

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, #options

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=, #constant?, #eql?, #evaluatable?, evaluate, #executable?, for, #initialize, #inspect, #operand, #optimize, #prefixes, prefixes, prefixes=, #rewrite, #to_sxp, #to_sxp_bin, #variable?

Methods included from Expression

cast, #constant?, #evaluate, extension, extensions, for, new, open, #optimize, parse, register_extension, #to_sxp_bin, #variable?

Constructor Details

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

Instance Method Details

#apply(term) ⇒ RDF::Literal::Boolean

Returns true if the operand is an RDF::Literal::Numeric, false otherwise.

Parameters:

Returns:

  • (RDF::Literal::Boolean) —

    true or false

Raises:

  • (TypeError) —

    if the operand is not an RDF term



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# File 'lib/sparql/algebra/operator/is_numeric.rb', line 29

def apply(term)
  case term
    when RDF::Literal::NonPositiveInteger then RDF::Literal::FALSE
    when RDF::Literal::NonNegativeInteger then RDF::Literal::FALSE
    when RDF::Literal::Long then RDF::Literal::FALSE
    when RDF::Literal::Numeric then RDF::Literal::TRUE
    when RDF::Term    then RDF::Literal::FALSE
    else raise TypeError, "expected an RDF::Term, but got #{term.inspect}"
  end
end