import strings fn test_sb() { mut sb := strings.Builder{} sb.write('hi') sb.write('!') sb.write('hello') assert sb.str() == 'hi!hello' sb = strings.new_builder(10) sb.write('a') sb.write('b') println(sb.str()) assert sb.str() == 'ab' } const ( n = 100000 ) fn test_big_sb() { mut sb := strings.new_builder(100) for i in 0..n { sb.writeln(i.str()) } s := sb.str() lines := s.split_into_lines() assert lines.len == n assert lines[0] == '0' assert lines[1] == '1' assert lines[777] == '777' assert lines[98765] == '98765' }