# File lib/rvm/environment/sets.rb, line 109 def perform_set_operation(*args) options = extract_options!(args) environment = extract_environment!(options) identifier = normalize_set_identifier(environment) # Uses yaml when we have multiple identifiers. uses_yaml = !environment.nil? options.merge!(:yaml => true) if uses_yaml args.unshift(identifier) unless identifier.nil? args << options result = rvm(*args) uses_yaml ? YAML.load(result.stdout) : result end