Method: RDF::Queryable#first_predicate

Defined in:

lib/rdf/mixin/queryable.rb

#first_predicate ⇒ RDF::URI #first_predicate(pattern) ⇒ RDF::URI

Queries self for an RDF statement matching the given pattern and returns the statement’s predicate term.

Returns nil if no statements match pattern.

Overloads:

• #first_predicate ⇒ RDF::URI

  Returns:

  • (RDF::URI)
• #first_predicate(pattern) ⇒ RDF::URI

  Parameters:

  • pattern (RDF::Query, RDF::Statement, Array(RDF::Term), Hash)

  Returns:

  • (RDF::URI)

Since:

• 0.1.9

# File 'lib/rdf/mixin/queryable.rb', line 214

def first_predicate(pattern = nil)
  __send__(*(pattern ? [:query, pattern] : [:each])) do |statement|
    return statement.predicate
  end
  return nil
end