22 — Terminal menu — a small TUI

A TUI (text user interface) is a menu you drive with the keyboard. The example examples/terminal-menu.nme shows three choices, waits for an answer, does what you picked, and then shows the menu again. It is a learning project, not advice.

Run it and feed it two answers — 1 greets you, then 3 quits. Because the loop goes back to the menu after the first answer, the menu appears twice:

printf '1\n3\n' | nme r examples/terminal-menu

1) greet
2) dice
3) quit
choose: hello!
1) greet
2) dice
3) quit
choose: bye

#Steps

1. The use random latest line loads the dice function, and a text value holds the menu. \n means "new line" — it is how one string becomes three rows:

   # part of examples/terminal-menu.nme
   use random latest
   
   menu = "1) greet\n2) dice\n3) quit"
   

   copyrun it →

2. while True: makes an endless loop; show menu prints the choices and ask choice, "choose: " stores your answer:

   # part of examples/terminal-menu.nme
   while True:
       show menu
       ask choice, "choose: "
   

   copyrun it →

   The block starts at the indentation, exactly like Python.

3. The if/elif/else from guide 06 runs one branch per answer. The plain Python headers if choice == "1": mix freely with the NME lines show/break inside the same block:

   # part of examples/terminal-menu.nme
   while True:
       show menu
       ask choice, "choose: "
       if choice == "1":
           show "hello!"
       elif choice == "2":
           show random_number(1, 6)
       else:
           show "bye"
           break
   

   copyrun it →

   show random_number(1, 6) rolls the die from guide 10 on the spot; any other answer falls into else, prints bye, and leaves the loop with break — the one way out of while True:.

4. nme check verifies the syntax without running the loop:

   nme check examples/terminal-menu
   

   copy

   The Korean twin examples/terminal-menu.ko.nme uses the same while True: loop with ask 선택, "고르세요: "; nme r examples/terminal-menu.ko picks the same numbers and gets the same flow in Korean.

#Try it yourself

Add a fourth row 4) coin to menu, then a new elif choice == "4": branch that shows a random pick between two sides — guide 10 shows how. break still works; the extra number just adds another branch.

#What you learned

• while True: loops forever; break is the way out.
• A menu is show, ask, branch, then loop back.
• show/ask NME lines mix with plain Python if choice == "1": headers.
• \n inside a string makes a new line.