Class: SPARQL::Algebra::Operator::Round

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

Overview

The SPARQL logical round operator.

Returns the number with no fractional part that is closest to the argument. If there are two such numbers, then the one that is closest to positive infinity is returned. An error is raised if arg is not a numeric value.

[121] BuiltInCall ::= … ‘ROUND’ ‘(’ Expression ‘)’

Examples:

SPARQL Grammar

PREFIX : <http://example.org/>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
SELECT ?s ?num (ROUND(?num) AS ?round) WHERE {
 ?s :num ?num
}

SSE

(prefix
 ((: <http://example.org/>)
  (xsd: <http://www.w3.org/2001/XMLSchema#>))
 (project (?s ?num ?round)
  (extend ((?round (round ?num)))
   (bgp (triple ?s :num ?num)))))

See Also:

Constant Summary collapse

NAME = 
[:round]

Constants inherited from Unary

Unary::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 Unary

#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_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::Unary

Instance Method Details

#apply(operand, **options) ⇒ RDF::Literal

Returns the number with no fractional part that is closest to the argument. If there are two such numbers, then the one that is closest to positive infinity is returned. An error is raised if arg is not a numeric value.

Parameters:

  • operand (RDF::Literal) —

    the operand

Returns:

  • (RDF::Literal) —

    literal of same type

Raises:

  • (TypeError) —

    if the operand is not a numeric value



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# File 'lib/sparql/algebra/operator/round.rb', line 39

def apply(operand, **options)
  case operand
    when RDF::Literal::Numeric then operand.round
    else raise TypeError, "expected an RDF::Literal::Numeric, but got #{operand.inspect}"
  end
end