substring_before (REXML::Functions)

    # File src/rexml/functions.rb, line 155
                    def Functions::substring_before( string, test )
                            ruby_string = string(string)
                            ruby_index = ruby_string.index(string(test))
                            if ruby_index.nil?
                                    ""
                            else
                                    ruby_string[ 0...ruby_index ]
                            end
                    end