#zztermtest

This is a test command for the zzterm package. It provides examples of using zzterm in a very memory-efficient way by supporting a variety of "modes".

#echo mode

The echo mode runs a simple "echo" program where each rune is printed as-is and Enter starts a new line. ESC and Ctrl-C end the program, and all other keys are ignored. Regardless of the amount of input, this program uses zero allocation for all input and output.

// run with go run main.go -echo

var newLine = []byte("\r\n")

func echoMode(rw io.ReadWriter) {
	input := zzterm.NewInput()

	var start, last runtime.MemStats
	var count int
	runtime.ReadMemStats(&start)
	defer func() {
		runtime.ReadMemStats(&last)
		alloc := last.TotalAlloc - start.TotalAlloc
		fmt.Fprintf(rw, "\r\nMemory(%dB; %dKB)\r\n", alloc, alloc/1024)
		fmt.Fprintf(rw, "Keys received: %d\r\n", count)
	}()

	for {
		k, err := input.ReadKey(rw)
		if err != nil {
			log.Panic(err)
		}
		count++

		switch k.Type() {
		case zzterm.KeyRune:
			if _, err := rw.Write(input.Bytes()); err != nil {
				log.Panic(err)
			}
		case zzterm.KeyEnter:
			if _, err := rw.Write(newLine); err != nil {
				log.Panic(err)
			}
		case zzterm.KeyESC, zzterm.KeyCtrlC:
			// quit on ESC or Ctrl-C
			return
		}
	}
}

#info mode

The info mode runs a debug-style mode where each key is printed and mouse and memory usage are tracked. The memory allocations in this mode come from the calls to key.String() and mouse.String(), otherwise it reuses a 1KB output buffer to minimize write memory usage, with strconv.Append... family of functions to print numbers in an efficient way.

// run with go run main.go
// or go run main.go -info
// (this is the default mode)

#License

The BSD 3-Clause license.