Menu
You are encouraged to solve this task according to the task description, using any language you may know.
- Task
Given a prompt and a list containing a number of strings of which one is to be selected, create a function that:
- prints a textual menu formatted as an index value followed by its corresponding string for each item in the list;
- prompts the user to enter a number;
- returns the string corresponding to the selected index number.
The function should reject input that is not an integer or is out of range by redisplaying the whole menu before asking again for a number. The function should return an empty string if called with an empty list.
For test purposes use the following four phrases in a list:
fee fie huff and puff mirror mirror tick tock
- Note
This task is fashioned after the action of the Bash select statement.
11l
<lang 11l>V items = [‘fee fie’, ‘huff and puff’, ‘mirror mirror’, ‘tick tock’]
L
L(item) items print(‘#2. #.’.format(L.index + 1, item))
V reply = input(‘Which is from the three pigs: ’).trim(‘ ’) I !reply.is_digit() L.continue
I Int(reply) C 1..items.len print(‘You chose: ’items[Int(reply) - 1]) L.break</lang>
- Output:
1. fee fie 2. huff and puff 3. mirror mirror 4. tick tock Which is from the three pigs: a 1. fee fie 2. huff and puff 3. mirror mirror 4. tick tock Which is from the three pigs: 0 1. fee fie 2. huff and puff 3. mirror mirror 4. tick tock Which is from the three pigs: 2 You chose: huff and puff
Ada
<lang Ada>with ada.text_io,Ada.Strings.Unbounded; use ada.text_io, Ada.Strings.Unbounded;
procedure menu is type menu_strings is array (positive range <>) of Unbounded_String ; function "+" (s : string) return Unbounded_String is (To_Unbounded_String (s));
function choice (m : menu_strings; prompt : string) return string is begin if m'length > 0 then loop put_line (prompt); for i in m'range loop put_line (i'img &") " & To_String (m(i))); end loop; begin return To_String (m(positive'value (get_line))); exception when others => put_line ("Try again !"); end; end loop; end if; return ""; end choice;
begin put_line ("You chose " & choice ((+"fee fie",+"huff and puff",+"mirror mirror",+"tick tock"),"Enter your choice ")); end menu;</lang>
ALGOL 68
<lang algol68>PROC menu select := (FLEX[]STRING items, UNION(STRING, VOID) prompt)STRING: (
INT choice; IF LWB items <= UPB items THEN WHILE FOR i FROM LWB items TO UPB items DO printf(($g(0)") "gl$, i, items[i])) OD; CASE prompt IN (STRING prompt):printf(($g" "$, prompt)), (VOID):printf($"Choice ? "$) ESAC; read((choice, new line)); # WHILE # 1 > choice OR choice > UPB items DO SKIP OD; items[choice] ELSE "" FI
);
test:(
FLEX[0]STRING items := ("fee fie", "huff and puff", "mirror mirror", "tick tock"); STRING prompt := "Which is from the three pigs : ";
printf(($"You chose "g"."l$, menu select(items, prompt)))
)</lang> Output:
1) fee fie 2) huff and puff 3) mirror mirror 4) tick tock Which is from the three pigs : 2 You chose huff and puff.
Arturo
<lang rebol>menu: function [items][
selection: neg 1 while [not? in? selection 1..size items][ loop.with:'i items 'item -> print ~"|i+1|. |item|" inp: input "Enter a number: " if numeric? inp -> selection: to :integer inp ]
print items \ selection-1 ]
menu ["fee fie" "huff and puff" "mirror mirror" "tick tock"]</lang>
- Output:
1. fee fie 2. huff and puff 3. mirror mirror 4. tick tock Enter a number: something wrong 1. fee fie 2. huff and puff 3. mirror mirror 4. tick tock Enter a number: 5 1. fee fie 2. huff and puff 3. mirror mirror 4. tick tock Enter a number: 3 mirror mirror
AutoHotkey
<lang AutoHotkey>Menu(list:=""){ if !list ; if called with an empty list return ; return an empty string for i, v in x := StrSplit(list, "`n", "`r") string .= (string?"`n":"") i "- " v , len := StrLen(v) > len ? StrLen(v) : len while !x[Choice] InputBox , Choice, Please Select From Menu, % string ,, % 200<len*7 ? 200 ? len*7 , % 120 + x.count()*20 return x[Choice] }</lang> Examples:<lang AutoHotkey>list = ( fee fie huff and puff mirror mirror tick tock ) MsgBox % Menu(list) ; call menu with list MsgBox % Menu() ; call menu with empty list return</lang>
AWK
<lang AWK>
- syntax: GAWK -f MENU.AWK
BEGIN {
print("you picked:",menu("")) print("you picked:",menu("fee fie:huff and puff:mirror mirror:tick tock")) exit(0)
} function menu(str, ans,arr,i,n) {
if (str == "") { return } n = split(str,arr,":") while (1) { print("") for (i=1; i<=n; i++) { printf("%d - %s\n",i,arr[i]) } printf("? ") getline ans if (ans in arr) { return(arr[ans]) } print("invalid choice") }
} </lang>
Axe
In Axe, static data (such as strings) is laid out sequentially in memory. So the H in "HUFF" is the byte after the null terminator for "FIE". However, null terminators are only added to strings when they are stored with the store symbol →. strGet returns a pointer to the start of the nth null-terminated string in the data, which is why the strings must be laid out in memory correctly. <lang axe>"FEE FIE"→Str1 "HUFF AND PUFF"→Str2 "MIRROR MIRROR"→Str3 "TICK TOCK"→Str4 For(I,1,4)
Disp I▶Hex+3,":",strGet(Str1,I-1),i
End Disp "NUMBER? " input→A {A}-'0'→N If N<1 or N>4
Disp "BAD NUMBER",i Return
End Disp strGet(Str1,N-1),i</lang>
BASIC
<lang qbasic> function sel$(choices$(), prompt$)
if ubound(choices$) - lbound(choices$) = 0 then sel$ = "" ret$ = "" do for i = lbound(choices$) to ubound(choices$) print i; ": "; choices$(i) next i input ;prompt$, index if index <= ubound(choices$) and index >= lbound(choices$) then ret$ = choices$(index) while ret$ = "" sel$ = ret$
end function</lang>
Commodore BASIC
While the following example could be shortened to simply print the resulting string indexed by the user input, it is useful to demonstrate that larger menu-driven projects benefit from the use of the ON n... GOSUB
statement to pass control to larger subroutines.
<lang commodorebasic>1 rem menu 5 rem rosetta code 10 gosub 900
20 print chr$(147);chr$(14) 30 print " Menu " 35 print:print "Choose an incantation:":print 40 for i=1 to 5 45 print i;chr$(157);". ";op$(i,1) 50 next i:print 55 print "choose one: "; 60 get k$:if k$<"1" or k$>"5" then 60 65 k=val(k$):print chr$(147) 70 on k gosub 100,200,300,400,500 80 if k=5 then end
90 print:print "Press any key to continue." 95 get k$:if k$="" then 95 96 goto 20
100 rem fee fi 110 print op$(k,2) 115 return
200 rem huff puff 210 print op$(k,2) 215 return
300 rem mirror mirror 310 print op$(k,2) 315 return
400 rem tick tock 410 print op$(k,2) 415 return
500 rem quit 510 print op$(k,2):print "Goodbye!" 515 return
900 rem initialize 905 dim op$(10,2) 910 for a=1 to 5 915 read op$(a,1),op$(a,2) 920 next a 925 return
1000 data "Fee fi fo fum","I smell the blood of an Englishman!" 1005 data "Huff and puff","The house blew down!" 1010 data "Mirror, mirror","You seem to be the fairest of them all!" 1015 data "Tick tock","Time passes..." 1020 data "<Quit>","You decide to leave."</lang>
Batch File
Example 1 <lang dos>@echo off & setlocal enabledelayedexpansion
set "menuChoices="fee fie","huff and puff","mirror mirror","tick tock""
call :menu
pause>nul & exit
- menu
if defined menuChoices ( set "counter=0" & for %%a in (%menuChoices%) do ( set /a "counter+=1" set "currentMenuChoice=%%a" set option[!counter!]=!currentMenuChoice:"=! ) )
- tryagain
cls&echo. for /l %%a in (1,1,%counter%) do echo %%a^) !option[%%a]! echo. set /p "input=Choice 1-%counter%: " echo. for /l %%a in (1,1,%counter%) do ( if !input! equ %%a echo You chose [ %%a^) !option[%%a]! ] & goto :EOF ) echo. echo.Invalid Input. Please try again... pause goto :tryagain</lang> Example 2 <lang dos> @echo off
call:menu "fee fie" "huff and puff" "mirror mirror" "tick tock" pause>nul exit /b
- menu
cls setlocal enabledelayedexpansion set count=0 set reset=endlocal ^& goto menu
- menuloop
for %%i in (%*) do ( set /a count+=1 set string[!count!]=%%~i echo string[!count!] = %%~i ) echo. set /p choice=^> if "%choice%"=="" %reset% set "isNum=" for /f "delims=0123456789" %%i in ("%choice%") do set isNum=%%i if defined isNum %reset% if %choice% gtr %count% %reset% echo.!string[%choice%]! goto:eof </lang>
BBC BASIC
<lang bbcbasic> DIM list$(4)
list$() = "fee fie", "huff and puff", "mirror mirror", "tick tock" selected$ = FNmenu(list$(), "Please make a selection: ") PRINT selected$ END DEF FNmenu(list$(), prompt$) LOCAL index%, select$ IF SUM(list$()) = "" THEN = "" REPEAT CLS FOR index% = 0 TO DIM(list$() ,1) IF list$(index%)<>"" PRINT ; index% ":", list$(index%) NEXT PRINT prompt$ ; INPUT "" select$ index% = VAL(select$) IF select$<>STR$(index%) index% = -1 IF index%>=0 IF index%<=DIM(list$() ,1) IF list$(index%)="" index% = -1 UNTIL index%>=0 AND index%<=DIM(list$(), 1) = list$(index%)</lang>
Empty entries in the list are not offered as options, nor accepted as a selection.
Brat
<lang brat>menu = { prompt, choices |
true? choices.empty? { "" } { choices.each_with_index { c, i | p "#{i}. #{c}" }
selection = ask prompt
true? selection.numeric? { selection = selection.to_i true? selection < 0 || { selection >= choices.length } { p "Selection is out of range"; menu prompt, choices } { choices[selection] } } { p "Selection must be a number"; menu prompt, choices } }
}
p menu "Selection: " ["fee fie" "huff and puff" "mirror mirror" "tick tock"]</lang>
C
<lang c>#include <stdio.h>
- include <stdlib.h>
- include <string.h>
const char *menu_select(const char *const *items, const char *prompt);
int main(void) { const char *items[] = {"fee fie", "huff and puff", "mirror mirror", "tick tock", NULL}; const char *prompt = "Which is from the three pigs?";
printf("You chose %s.\n", menu_select(items, prompt));
return EXIT_SUCCESS; }
const char * menu_select(const char *const *items, const char *prompt) { char buf[BUFSIZ]; int i; int choice; int choice_max;
if (items == NULL) return NULL;
do { for (i = 0; items[i] != NULL; i++) { printf("%d) %s\n", i + 1, items[i]); } choice_max = i; if (prompt != NULL) printf("%s ", prompt); else printf("Choice? "); if (fgets(buf, sizeof(buf), stdin) != NULL) { choice = atoi(buf); } } while (1 > choice || choice > choice_max);
return items[choice - 1]; }</lang>
C#
<lang csharp> using System; using System.Collections.Generic;
public class Menu {
static void Main(string[] args) { List<string> menu_items = new List<string>() { "fee fie", "huff and puff", "mirror mirror", "tick tock" }; //List<string> menu_items = new List<string>(); Console.WriteLine(PrintMenu(menu_items)); Console.ReadLine(); } private static string PrintMenu(List<string> items) { if (items.Count == 0) return "";
string input = ""; int i = -1; do { for (int j = 0; j < items.Count; j++) Console.WriteLine("{0}) {1}", j, items[j]);
Console.WriteLine("What number?"); input = Console.ReadLine();
} while (!int.TryParse(input, out i) || i >= items.Count || i < 0); return items[i]; }
} </lang>
C++
<lang cpp>#include <iostream>
- include <string>
- include <vector>
void print_menu(const std::vector<std::string>& terms) {
for (size_t i = 0; i < terms.size(); i++) { std::cout << i + 1 << ") " << terms[i] << '\n'; }
}
int parse_entry(const std::string& entry, int max_number) {
int number = std::stoi(entry); if (number < 1 || number > max_number) { throw std::invalid_argument(""); }
return number;
}
std::string data_entry(const std::string& prompt, const std::vector<std::string>& terms) {
if (terms.empty()) { return ""; }
int choice; while (true) { print_menu(terms); std::cout << prompt;
std::string entry; std::cin >> entry;
try { choice = parse_entry(entry, terms.size()); return terms[choice - 1]; } catch (std::invalid_argument&) { // std::cout << "Not a valid menu entry!" << std::endl; } }
}
int main() {
std::vector<std::string> terms = {"fee fie", "huff and puff", "mirror mirror", "tick tock"}; std::cout << "You chose: " << data_entry("> ", terms) << std::endl;
} </lang>
Ceylon
<lang ceylon>"Run the module `menu`." shared void run() {
value selection = menu("fee fie", "huff And puff", "mirror mirror", "tick tock"); print(selection);
}
String menu(String* strings) { if(strings.empty) { return ""; } value entries = map(zipEntries(1..strings.size, strings)); while(true) { for(index->string in entries) { print("``index``) ``string``"); } process.write("> "); value input = process.readLine(); if(exists input, exists int = parseInteger(input), exists string = entries[int]) { return string; } } }
</lang>
Clojure
<lang clojure>(defn menu [prompt choices]
(if (empty? choices) "" (let [menutxt (apply str (interleave (iterate inc 1) (map #(str \space % \newline) choices)))] (println menutxt) (print prompt) (flush) (let [index (read-string (read-line))] ; verify (if (or (not (integer? index)) (> index (count choices)) (< index 1)) ; try again (recur prompt choices) ; ok (nth choices (dec index)))))))
(println "You chose: "
(menu "Which is from the three pigs: " ["fee fie" "huff and puff" "mirror mirror" "tick tock"]))</lang>
COBOL
<lang cobol> IDENTIFICATION DIVISION.
PROGRAM-ID. Test-Prompt-Menu.
DATA DIVISION. WORKING-STORAGE SECTION.
01 Num-Options USAGE UNSIGNED-INT VALUE 4. 01 Example-Menu. 03 Example-Options-Data. 05 FILLER PIC X(30) VALUE "fee fie". 05 FILLER PIC X(30) VALUE "huff and puff". 05 FILLER PIC X(30) VALUE "mirror mirror". 05 FILLER PIC X(30) VALUE "tick tock".
03 Example-Options-Values REDEFINES Example-Options-Data. 05 Example-Options PIC X(30) OCCURS 4 TIMES.
01 Chosen-Option PIC X(30).
PROCEDURE DIVISION. CALL "Prompt-Menu" USING BY CONTENT Num-Options BY CONTENT Example-Menu BY REFERENCE Chosen-Option
DISPLAY "You chose: " Chosen-Option
GOBACK .
END PROGRAM Test-Prompt-Menu.
IDENTIFICATION DIVISION. PROGRAM-ID. Prompt-Menu.
DATA DIVISION. LOCAL-STORAGE SECTION. 01 User-Input USAGE UNSIGNED-INT. 01 Input-Flag PIC X. 88 Valid-Input VALUE "Y".
01 Options-Index USAGE UNSIGNED-INT. 01 Index-Display PIC Z(10).
LINKAGE SECTION.
01 Num-Options USAGE UNSIGNED-INT. 01 Menu-Options. 03 Options-Table PIC X(30) OCCURS 0 TO 10000000 TIMES DEPENDING ON Num-Options.
01 Chosen-Option PIC X(30).
PROCEDURE DIVISION USING Num-Options Menu-Options Chosen-Option. Main. IF Num-Options = 0 MOVE SPACES TO Chosen-Option GOBACK END-IF
PERFORM UNTIL Valid-Input PERFORM Display-Menu-Options
DISPLAY "Choose an option: " WITH NO ADVANCING ACCEPT User-Input
PERFORM Validate-Input END-PERFORM
MOVE Options-Table (User-Input) TO Chosen-Option
GOBACK .
Display-Menu-Options. PERFORM VARYING Options-Index FROM 1 BY 1 UNTIL Num-Options < Options-Index MOVE Options-Index TO Index-Display DISPLAY Index-Display ". " Options-Table (Options-Index) END-DISPLAY END-PERFORM .
Validate-Input. IF User-Input = 0 OR > Num-Options DISPLAY "Invalid input." ELSE SET Valid-Input TO TRUE END-IF .
END PROGRAM Prompt-Menu.</lang>
Common Lisp
<lang lisp>(defun select (prompt choices)
(if (null choices) "" (do (n) ((and n (<= 0 n (1- (length choices)))) (nth n choices)) (format t "~&~a~%" prompt) (loop for n from 0 for c in choices do (format t " ~d) ~a~%" n c)) (force-output) (setf n (parse-integer (read-line *standard-input* nil) :junk-allowed t)))))</lang>
D
<lang d>import std.stdio, std.conv, std.string, std.array, std.typecons;
string menuSelect(in string[] entries) {
static Nullable!(int, -1) validChoice(in string input, in int nEntries) pure nothrow { try { immutable n = input.to!int; return typeof(return)((n >= 0 && n <= nEntries) ? n : -1); } catch (Exception e) // Very generic return typeof(return)(-1); // Not valid. }
if (entries.empty) return "";
while (true) { "Choose one:".writeln; foreach (immutable i, const entry; entries) writefln(" %d) %s", i, entry); "> ".write; immutable input = readln.chomp; immutable choice = validChoice(input, entries.length - 1); if (choice.isNull) "Wrong choice.".writeln; else return entries[choice]; // We have a valid choice. }
}
void main() {
immutable items = ["fee fie", "huff and puff", "mirror mirror", "tick tock"]; writeln("You chose '", items.menuSelect, "'.");
}</lang>
- Output:
Choose one: 0) fee fie 1) huff and puff 2) mirror mirror 3) tick tock > 2 You chose 'mirror mirror'.
Delphi
<lang Delphi> program Menu;
{$APPTYPE CONSOLE}
uses
System.SysUtils;
function ChooseMenu(Options: TArray<string>; Prompt: string): string; var
index: Integer; value: string;
begin
if Length(Options) = 0 then exit(); repeat writeln; for var i := 0 to length(Options) - 1 do writeln(i + 1, '. ', Options[i]); write(#10, Prompt, ' '); Readln(value); index := StrToIntDef(value, -1); until (index > 0) and (index <= length(Options)); Result := Options[index];
end;
begin
writeln('You picked ', ChooseMenu(['fee fie', 'huff and puff', 'mirror mirror', 'tick tock'], 'Enter number: ')); readln;
end.</lang>
- Output:
1. fee fie 2. huff and puff 3. mirror mirror 4. tick tock Enter number: 5 1. fee fie 2. huff and puff 3. mirror mirror 4. tick tock Enter number: 2 You picked mirror mirror
Elixir
<lang elixir>defmodule Menu do
def select(_, []), do: "" def select(prompt, items) do IO.puts "" Enum.with_index(items) |> Enum.each(fn {item,i} -> IO.puts " #{i}. #{item}" end) answer = IO.gets("#{prompt}: ") |> String.strip case Integer.parse(answer) do {num, ""} when num in 0..length(items)-1 -> Enum.at(items, num) _ -> select(prompt, items) end end
end
- test empty list
response = Menu.select("Which is empty", []) IO.puts "empty list returns: #{inspect response}"
- "real" test
items = ["fee fie", "huff and puff", "mirror mirror", "tick tock"] response = Menu.select("Which is from the three pigs", items) IO.puts "you chose: #{inspect response}"</lang>
- Output:
empty list returns: "" 0. fee fie 1. huff and puff 2. mirror mirror 3. tick tock Which is from the three pigs: 4 0. fee fie 1. huff and puff 2. mirror mirror 3. tick tock Which is from the three pigs: 3 you chose: "tick tock"
ERRE
<lang ERRE> PROCEDURE Selection(choices$[],prompt$->sel$)
IF UBOUND(choices$,1)-LBOUND(choices$,1)=0 THEN sel$="" EXIT PROCEDURE END IF ret$="" REPEAT FOR i=LBOUND(choices$,1) TO UBOUND(choices$,1) DO PRINT(i;": ";choices$[i]) END FOR PRINT(prompt$;) INPUT(index) IF index<=UBOUND(choices$,1) AND index>=LBOUND(choices$,1) THEN ret$=choices$[index] END IF UNTIL ret$<>"" sel$=ret$
END PROCEDURE </lang>
Euphoria
<lang euphoria>include get.e
function menu_select(sequence items, object prompt)
if length(items) = 0 then return "" else for i = 1 to length(items) do printf(1,"%d) %s\n",{i,items[i]}) end for if atom(prompt) then prompt = "Choice?" end if return items[prompt_number(prompt,{1,length(items)})] end if
end function
constant items = {"fee fie", "huff and puff", "mirror mirror", "tick tock"} constant prompt = "Which is from the three pigs? "
printf(1,"You chose %s.\n",{menu_select(items,prompt)})</lang>
F#
<lang fsharp>open System
let rec menuChoice (options : string list) prompt =
if options = [] then "" else for i = 0 to options.Length - 1 do printfn "%d. %s" (i + 1) options.[i]
printf "%s" prompt let input = Int32.TryParse(Console.ReadLine())
match input with | true, x when 1 <= x && x <= options.Length -> options.[x - 1] | _, _ -> menuChoice options prompt
[<EntryPoint>] let main _ =
let menuOptions = ["fee fie"; "huff and puff"; "mirror mirror"; "tick tock"] let choice = menuChoice menuOptions "Choose one: " printfn "You chose: %s" choice
0</lang>
Factor
<lang factor>USING: formatting io kernel math math.parser sequences ;
- print-menu ( seq -- )
[ 1 + swap "%d - %s\n" printf ] each-index "Your choice? " write flush ;
- (select) ( seq -- result )
dup print-menu readln string>number dup integer? [ drop 1 - swap 2dup bounds-check? [ nth ] [ nip (select) ] if ] [ drop (select) ] if* ;
- select ( seq -- result ) [ "" ] [ (select) ] if-empty ;</lang>
Example usage:
( scratchpad ) { "fee fie" "huff and puff" "mirror mirror" "tick tock" } select 1 - fee fie 2 - huff and puff 3 - mirror mirror 4 - tick tock Your choice? 1 --- Data stack: "fee fie"
Fantom
<lang fantom>class Main {
static Void displayList (Str[] items) { items.each |Str item, Int index| { echo ("$index: $item") } }
public static Str getChoice (Str[] items) { selection := -1 while (selection == -1) { displayList (items) Env.cur.out.print ("Select: ").flush input := Int.fromStr(Env.cur.in.readLine, 10, false) if (input != null) { if (input >= 0 && input < items.size) { selection = input } } echo ("Try again") } return items[selection] }
public static Void main () { choice := getChoice (["fee fie", "huff and puff", "mirror mirror", "tick tock"]) echo ("You chose: $choice") }
}</lang>
Forth
Idiomatic Forth
Out of the box Forth does not have lists. This version uses strings and a vector table, which arguably is more how one would do this task in Forth. It returns a nil string if a nil string is given otherwise the input string becomes the title of the menu. <lang Forth>\ Rosetta Code Menu Idiomatic Forth
\ vector table compiler
- CASE: ( -- ) CREATE ;
- | ( -- <text>) ' , ; IMMEDIATE
- ;CASE ( -- ) DOES> SWAP CELLS + @ EXECUTE ;
- NIL ( -- addr len) S" " ;
- FEE ( -- addr len) S" fee fie" ;
- HUFF ( -- addr len) S" huff and puff" ;
- MIRROR ( -- addr len) S" mirror mirror" ;
- TICKTOCK ( -- addr len) S" tick tock" ;
CASE: SELECT ( n -- addr len)
| NIL | FEE | HUFF | MIRROR | TICKTOCK
- CASE
CHAR 1 CONSTANT '1' CHAR 4 CONSTANT '4'
- BETWEEN ( n low hi -- ?) 1+ WITHIN ;
- MENU ( addr len -- addr len )
DUP 0= IF 2DROP NIL EXIT ELSE BEGIN CR CR 2DUP 3 SPACES TYPE CR ." 1 " 1 SELECT TYPE CR ." 2 " 2 SELECT TYPE CR ." 3 " 3 SELECT TYPE CR ." 4 " 4 SELECT TYPE CR ." Choice: " KEY DUP EMIT DUP '1' '4' BETWEEN 0= WHILE DROP REPEAT -ROT 2DROP \ drop input string CR [CHAR] 0 - SELECT THEN
- </lang>
If there must be lists
Here we extend Forth to support simple lists and complete the task using the language extensions. <lang forth>\ Rosetta Menu task with Simple lists in Forth
- STRING, ( caddr len -- ) HERE OVER CHAR+ ALLOT PLACE ;
- " ( -- ) [CHAR] " PARSE STRING, ;
- { ( -- ) ALIGN 0 C, ;
- } ( -- ) { ;
- {NEXT} ( str -- next_str) COUNT + ;
- {NTH} ( n array_addr -- str) SWAP 0 DO {NEXT} LOOP ;
- {LEN} ( array_addr -- ) \ count strings in a list
0 >R \ Counter on Rstack {NEXT} \ skip 1st empty string BEGIN {NEXT} DUP C@ \ Fetch length byte WHILE \ While true R> 1+ >R \ Inc. counter REPEAT DROP R> ; \ return counter to data stack
- {TYPE} ( $ -- ) COUNT TYPE ;
- '"' ( -- ) [CHAR] " EMIT ;
- {""} ( $ -- ) '"' SPACE {TYPE} '"' SPACE ;
- }PRINT ( n array -- ) {NTH} {TYPE} ;
\ ===== TASK BEGINS ===== CREATE GOODLIST
{ " fee fie" " huff and puff" " mirror mirror" " tick tock" }
CREATE NIL { }
CHAR 1 CONSTANT '1' CHAR 4 CONSTANT '4' CHAR 0 CONSTANT '0'
- BETWEEN ( n low hi -- ?) 1+ WITHIN ;
- .MENULN ( n -- n) DUP '0' + EMIT SPACE OVER }PRINT ;
- MENU ( list -- string )
DUP {LEN} 0= IF DROP NIL ELSE BEGIN CR CR 1 .MENULN CR 2 .MENULN CR 3 .MENULN CR 4 .MENULN CR ." Choice: " KEY DUP EMIT DUP '1' '4' BETWEEN 0= WHILE DROP REPEAT [CHAR] 0 - CR SWAP {NTH} THEN
- </lang>
Test at the gForth console
GOODLIST MENU 1 fee fie 2 huff and puff 3 mirror mirror 4 tick tock Choice: 0 1 fee fie 2 huff and puff 3 mirror mirror 4 tick tock Choice: Q 1 fee fie 2 huff and puff 3 mirror mirror 4 tick tock Choice: 2 ok {TYPE} huff and puff ok ok NIL MENU ok {TYPE} ok
Fortran
Please find the build instructions in the comments at the start of the FORTRAN 2008 source. Compiler: gfortran from the GNU compiler collection. Command interpreter: bash. <lang FORTRAN> !a=./f && make $a && OMP_NUM_THREADS=2 $a !gfortran -std=f2008 -Wall -fopenmp -ffree-form -fall-intrinsics -fimplicit-none f.f08 -o f
module menu public :: selector contains
function selector(title,options) result(choice) character(len=*),intent(in) :: title character(len=*),dimension(:),intent(in) :: options character(len=len(options)) :: choice integer :: i,ichoose,ios,n
choice = ""
n = size(options) if (n > 0) then do print "(a)",title print "(i8,"", "",a)",(i,options(i),i=1,n) read (*,fmt="(i8)",iostat=ios) ichoose
if (ios == -1) exit ! EOF error if (ios /= 0) cycle ! other error if (ichoose < 1) cycle if (ichoose > n) cycle ! out-of-bounds
choice = options(ichoose) exit end do end if end function selector end module menu
program menu_demo use menu character(len=14),dimension(:),allocatable :: zero_items,fairytale character(len=len(zero_items)) :: s
!! empty list demo allocate(zero_items(0)) print "(a)","input items:",zero_items s = selector('Choose from the empty list',zero_items) print "(a)","returned:",s if (s == "") print "(a)","(an empty string)"
!! Fairy tale demo allocate(fairytale(4)) fairytale = (/'fee fie ','huff and puff ', & 'mirror mirror ','tick tock '/) print "(a)","input items:",fairytale s = selector('Choose a fairy tale',fairytale) print "(a)","returned: ",s if (s == "") print "(a)","(an empty string)"
end program menu_demo
</lang>
Gambas
<lang gambas> Public Sub Main()
Dim asMenu As String[] = ["fee fie", "huff And puff", "mirror mirror", "tick tock"] Dim sValuePrompt As String = "Please select one of the above numbers> " Dim sChoice As String Dim sFeedbackFormat As String = "You have chosen '&1'\r\n"
sChoice = Menu(asMenu, sValuePrompt) If sChoice = "" Then Print "menu returned an empty string" Else Print Subst(sFeedbackFormat, sChoice) Endif
End
Private Function Menu(asChoices As String[], sPrompt As String) As String
Dim sReturnValue As String = "" Dim sMenuLineFormat As String = "&1) &2" Dim sAnswer As String Dim iAnswer As Integer Dim iIndex As Integer = 0 Dim sMenuItem As String
If Not IsNull(asChoices) Then If asChoices.Count > 0 Then Do For iIndex = 0 To asChoices.Max sMenuItem = asChoices[iIndex] Print Subst(sMenuLineFormat, iIndex, sMenuItem) Next
Print sPrompt Input sAnswer
If IsNumber(sAnswer) Then iAnswer = sAnswer If (0 <= iAnswer) And (iAnswer <= asChoices.Max) Then sReturnValue = asChoices[iAnswer] Break Endif Endif Loop Endif Endif
Return sReturnValue
End </lang>
Go
<lang go>package main
import "fmt"
func menu(choices []string, prompt string) string {
if len(choices) == 0 { return "" } var c int for { fmt.Println("") for i, s := range choices { fmt.Printf("%d. %s\n", i+1, s) } fmt.Print(prompt) _, err := fmt.Scanln(&c)
if err == nil && c > 0 && c <= len(choices) { break } } return choices[c-1]
}
func main() {
pick := menu(nil, "No prompt") fmt.Printf("No choices, result = %q\n", pick)
choices := []string{ "fee fie", "huff and puff", "mirror mirror", "tick tock", } pick = menu(choices, "Enter number: ") fmt.Printf("You picked %q\n", pick)
}</lang> Output:
No choices, result = "" 1. fee fie 2. huff and puff 3. mirror mirror 4. tick tock Enter number: 2 You picked "huff and puff"
Haskell
<lang Haskell>module RosettaSelect where
import Data.Maybe (listToMaybe) import Control.Monad (guard)
select :: [String] -> IO String select [] = return "" select menu = do
putStr $ showMenu menu putStr "Choose an item: " choice <- getLine maybe (select menu) return $ choose menu choice
showMenu :: [String] -> String showMenu menu = unlines [show n ++ ") " ++ item | (n, item) <- zip [1..] menu]
choose :: [String] -> String -> Maybe String choose menu choice = do
n <- maybeRead choice guard $ n > 0 listToMaybe $ drop (n-1) menu
maybeRead :: Read a => String -> Maybe a maybeRead = fmap fst . listToMaybe . filter (null . snd) . reads</lang>
Example usage, at the GHCI prompt: <lang Haskell>*RosettaSelect> select ["fee fie", "huff and puff", "mirror mirror", "tick tock"] 1) fee fie 2) huff and puff 3) mirror mirror 4) tick tock Choose an item: 3 "mirror mirror"
- RosettaSelect></lang>
HicEst
<lang HicEst>CHARACTER list = "fee fie,huff and puff,mirror mirror,tick tock,", answer*20
POP(Menu=list, SelTxt=answer)
SUBROUTINE list ! callback procedure must have same name as menu argument
! Subroutine with no arguments: all objects are global ! The global variable $$ returns the selected list index WRITE(Messagebox, Name) answer, $$
END</lang>
Icon and Unicon
<lang Icon>procedure main()
L := ["fee fie", "huff and puff", "mirror mirror", "tick tock"]
every i := 1 to *L do
write(i,") ",L[i])
repeat {
writes("Choose a number from the menu above: ") a := read() if 1 <= integer(a) <= i then break }
write("You selected ",a," ==> ",L[a]) end</lang>
J
Solution: <lang j> CHOICES =: ];._2 'fee fie;huff and puff;mirror mirror;tick tock;' PROMPT =: 'Which is from the three pigs? '
showMenu =: smoutput@:(,"1~ (' ' ,.~ 3 ": i.@:(1 ,~ #))) read_stdin =: 1!:1@:1:
menu =: '? '&$: :(4 : 0)
NB. use: [prompt] menu choice_array CHOICES =. y if. 0 = # CHOICES do. return. end. PROMPT =. x whilst. RESULT -.@:e. i. # CHOICES do. showMenu CHOICES smoutput PROMPT RESULT =. _1 ". read_stdin end. RESULT {:: CHOICES
) </lang>
See Talk page for explanation.
Java
<lang java5>public static String select(List<String> list, String prompt){
if(list.size() == 0) return ""; Scanner sc = new Scanner(System.in); String ret = null; do{ for(int i=0;i<list.size();i++){ System.out.println(i + ": "+list.get(i)); } System.out.print(prompt); int index = sc.nextInt(); if(index >= 0 && index < list.size()){ ret = list.get(index); } }while(ret == null); return ret;
}</lang>
JavaScript
<lang javascript>const readline = require('readline');
async function menuSelect(question, choices) {
if (choices.length === 0) return ;
const prompt = choices.reduce((promptPart, choice, i) => { return promptPart += `${i + 1}. ${choice}\n`; }, );
let inputChoice = -1; while (inputChoice < 1 || inputChoice > choices.length) { inputChoice = await getSelection(`\n${prompt}${question}: `); }
return choices[inputChoice - 1];
}
function getSelection(prompt) {
return new Promise((resolve) => { const lr = readline.createInterface({ input: process.stdin, output: process.stdout });
lr.question(prompt, (response) => { lr.close(); resolve(parseInt(response) || -1); }); });
}
const choices = ['fee fie', 'huff and puff', 'mirror mirror', 'tick tock']; const question = 'Which is from the three pigs?'; menuSelect(question, choices).then((answer) => {
console.log(`\nYou chose ${answer}`);
});</lang>
jq
This version uses jq 1.5's 'input' builtin to read programmatically from STDIN. <lang jq>def choice:
def read(prompt; max): def __read__: prompt, ( input as $input | if ($input|type) == "number" and 0 < $input and $input <= max then $input else __read__ end); __read__; if length == 0 then "" else . as $in | ("Enter your choice:\n" + (reduce range(0; length) as $i (""; . + "\($i + 1): \($in[$i])\n")) ) as $prompt | read($prompt; length) as $read | if ($read|type) == "string" then $read else "Thank you for selecting \($in[$read-1])" end end ;</lang>
Example: <lang jq>["fee fie", "huff and puff", "mirror mirror", "tick tock"] | choice</lang> <lang sh> $ jq -n -r -f Menu.jq Enter your choice: 1: fee fie 2: huff and puff 3: mirror mirror 4: tick tock
5 Enter your choice: 1: fee fie 2: huff and puff 3: mirror mirror 4: tick tock
1 Thank you for selecting fee fie</lang>
Julia
<lang julia>using Printf
function _menu(items)
for (ind, item) in enumerate(items) @printf " %2i) %s\n" ind item end
end
_ok(::Any,::Any) = false function _ok(reply::AbstractString, itemcount)
n = tryparse(Int, reply) return isnull(n) || 0 ≤ get(n) ≤ itemcount
end
"Prompt to select an item from the items" function _selector(items, prompt::AbstractString)
isempty(items) && return "" reply = -1 itemcount = length(items) while !_ok(reply, itemcount) _menu(items) print(prompt) reply = strip(readline(STDIN)) end return items[parse(Int, reply)]
end
items = ["fee fie", "huff and puff", "mirror mirror", "tick tock"] item = _selector(items, "Which is from the three pigs: ") println("You chose: ", item)</lang>
Kotlin
<lang scala>// version 1.1.2
fun menu(list: List<String>): String {
if (list.isEmpty()) return "" val n = list.size while (true) { println("\n M E N U\n") for (i in 0 until n) println("${i + 1}: ${list[i]}") print("\nEnter your choice 1 - $n : ") val index = readLine()!!.toIntOrNull() if (index == null || index !in 1..n) continue return list[index - 1] }
}
fun main(args: Array<String>) {
val list = listOf( "fee fie", "huff and puff", "mirror mirror", "tick tock" ) val choice = menu(list) println("\nYou chose : $choice")
}</lang> Sample session:
- Output:
M E N U 1: fee fie 2: huff and puff 3: mirror mirror 4: tick tock Enter your choice 1 - 4 : 0 M E N U 1: fee fie 2: huff and puff 3: mirror mirror 4: tick tock Enter your choice 1 - 4 : asdf M E N U 1: fee fie 2: huff and puff 3: mirror mirror 4: tick tock Enter your choice 1 - 4 : 2 You chose : huff and puff
langur
<lang langur>val .select = f(.entries) {
if not isArray(.entries): throw "invalid args" if len(.entries) == 0: return ZLS
# print the menu writeln join "\n", map(f $"\.i:2;: \.e;", .entries, 1..len .entries)
val .idx = toNumber read( "Select entry #: ", f(.x) { if not matching(RE/^[0-9]+$/, .x): return false val .y = toNumber .x .y > 0 and .y <= len(.entries) }, "invalid selection\n", -1, )
.entries[.idx]
}
writeln .select(["fee fie", "eat pi", "huff and puff", "tick tock"])</lang>
- Output:
1: fee fie 2: eat pi 3: huff and puff 4: tick tock Select entry #: 7 invalid selection Select entry #: 2 eat pi
Logo
<lang logo>to select :prompt [:options]
foreach :options [(print # ?)] forever [ type :prompt type "| | make "n readword if (and [number? :n] [:n >= 1] [:n <= count :options]) [output item :n :options] print sentence [Must enter a number between 1 and] count :options ]
end
print equal? [huff and puff] (select
[Which is from the three pigs?] [fee fie] [huff and puff] [mirror mirror] [tick tock])
</lang>
Lua
<lang lua>function select (list)
if not list or #list == 0 then return "" end local last, sel = #list repeat for i,option in ipairs(list) do io.write(i, ". ", option, "\n") end io.write("Choose an item (1-", tostring(last), "): ") sel = tonumber(string.match(io.read("*l"), "^%d+$")) until type(sel) == "number" and sel >= 1 and sel <= last return list[math.floor(sel)]
end
print("Nothing:", select {}) print() print("You chose:", select {"fee fie", "huff and puff", "mirror mirror", "tick tock"})</lang>
- Output:
Nothing: 1. fee fie 2. huff and puff 3. mirror mirror 4. tick tock Choose an item (1-4): 0 1. fee fie 2. huff and puff 3. mirror mirror 4. tick tock Choose an item (1-4): a 1. fee fie 2. huff and puff 3. mirror mirror 4. tick tock Choose an item (1-4): 1.7 1. fee fie 2. huff and puff 3. mirror mirror 4. tick tock Choose an item (1-4): 10 1. fee fie 2. huff and puff 3. mirror mirror 4. tick tock Choose an item (1-4): 3 You chose: mirror mirror
Mathematica / Wolfram Language
Interpreter: Wolfram Desktop and Wolfram Desktop Kernel
Redisplays the list of choices on every invalid input as per the task description. In the notebook interface (of Wolfram Desktop, at least), Print[] would most pragmatically be located outside of the loop because Input[] uses a dialog box.
<lang Mathematica>textMenu[data_List] := Module[{choice},
If[Length@data == 0, Return@""]; While[!(IntegerQ@choice && Length@data >= choice > 0), MapIndexed[Print[#21, ") ", #1]&, data]; choice = Input["Enter selection..."] ]; datachoice ]</lang>
- Kernel (REPL) output (function definition omitted):
Wolfram Desktop Kernel (using Wolfram Language 12.0.0) for Microsoft Windows (64-bit) Copyright 1988-2019 Wolfram Research, Inc. In[1]:= (*! ELIDED !*) In[2]:= textMenu[{}] Out[2]= In[3]:= textMenu[{"fee fie", "huff and puff", "mirror mirror", "tick tock"}] 1) fee fie 2) huff and puff 3) mirror mirror 4) tick tock Enter selection...0 1) fee fie 2) huff and puff 3) mirror mirror 4) tick tock Enter selection...5 1) fee fie 2) huff and puff 3) mirror mirror 4) tick tock Enter selection...-1 1) fee fie 2) huff and puff 3) mirror mirror 4) tick tock Enter selection...fee fie 1) fee fie 2) huff and puff 3) mirror mirror 4) tick tock Enter selection...3 Out[3]= mirror mirror
MATLAB
<lang MATLAB>function sucess = menu(list)
if numel(list) == 0 sucess = ; return end
while(true) disp('Please select one of these options:'); for i = (1:numel(list)) disp([num2str(i) ') ' list{i}]); end disp([num2str(numel(list)+1) ') exit']); try key = input(':: '); if key == numel(list)+1 break elseif (key > numel(list)) || (key < 0) continue else disp(['-> ' list{key}]); end catch continue end end sucess = true;
end </lang>
min
min has an operator choose
that nearly conforms to this task. The input list is altered so that the choice can be returned, and the empty list case is handled.
<lang min>(
:prompt =list (list bool) (list (' dup append) map prompt choose) ("") if
) :menu
("fee fie" "huff and puff" "mirror mirror" "tick tock") "Enter an option" menu "You chose: " print! puts!</lang>
- Output:
Enter an option 1 - fee fie 2 - huff and puff 3 - mirror mirror 4 - tick tock Enter your choice (1 - 4): 5 Invalid choice. 1 - fee fie 2 - huff and puff 3 - mirror mirror 4 - tick tock Enter your choice (1 - 4): 1 You chose: fee fie
Modula-2
<lang modula2>MODULE Menu;
FROM InOut IMPORT WriteString, WriteCard, WriteLn, ReadCard;
CONST StringLength = 100;
MenuSize = 4;
TYPE String = ARRAY[0..StringLength-1] OF CHAR;
VAR menu : ARRAY[0..MenuSize] OF String;
selection, index : CARDINAL;
BEGIN
menu[1] := "fee fie"; menu[2] := "huff and puff"; menu[3] := "mirror mirror"; menu[4] := "tick tock"; FOR index := 1 TO HIGH(menu) DO WriteString("["); WriteCard( index,1); WriteString( "] "); WriteString( menu[index]); WriteLn; END;(*of FOR*) WriteString("Choose what you want : "); ReadCard(selection); IF (selection <= HIGH(menu)) AND (selection > 0) THEN WriteString("You have chosen: "); WriteString( menu[selection]); WriteLn; ELSE WriteString("Selection is out of range!"); WriteLn; END (*of IF*)
END Menu.</lang>
MUMPS
<lang MUMPS>MENU(STRINGS,SEP)
;http://rosettacode.org/wiki/Menu NEW I,A,MAX ;I is a loop variable ;A is the string read in from the user ;MAX is the number of substrings in the STRINGS list ;SET STRINGS="fee fie^huff and puff^mirror mirror^tick tock" SET MAX=$LENGTH(STRINGS,SEP) QUIT:MAX=0 ""
WRITEMENU
FOR I=1:1:MAX WRITE I,": ",$PIECE(STRINGS,SEP,I),! READ:30 !,"Choose a string by its index: ",A,! IF (A<1)!(A>MAX)!(A\1'=A) GOTO WRITEMENU KILL I,MAX QUIT $PIECE(STRINGS,SEP,A)</lang>
Usage:
USER>W !,$$MENU^ROSETTA("fee fie^huff and puff^mirror mirror^tick tock","^") 1: fee fie 2: huff and puff 3: mirror mirror 4: tick tock Choose a string by its index: 3 mirror mirror USER>W !,$$MENU^ROSETTA("fee fie^huff and puff^mirror mirror^tick tock","^") 1: fee fie 2: huff and puff 3: mirror mirror 4: tick tock Choose a string by its index: 5 1: fee fie 2: huff and puff 3: mirror mirror 4: tick tock Choose a string by its index: A 1: fee fie 2: huff and puff 3: mirror mirror 4: tick tock Choose a string by its index: 0 1: fee fie 2: huff and puff 3: mirror mirror 4: tick tock Choose a string by its index: 1 fee fie
Nanoquery
<lang Nanoquery>def _menu($items) for ($i = 0) ($i < len($items)) ($i = $i + 1) println " " + $i + ") " + $items[$i] end end
def _ok($reply, $itemcount) try $n = int($reply) return (($n >= 0) && ($n < $itemcount)) catch return $false end end
def selector($items, $pmt) // Prompt to select an item from the items if (len($items) = 0) return "" end $reply = -1 $itemcount = len($items) while !_ok($reply, $itemcount) _menu($items) println $pmt $reply = int(input()) end return $items[$reply] end
$items = list() append $items "fee fie" "huff and puff" "mirror mirror" "tick tock" $item = selector($items, "Which is from the three pigs: ") println "You chose: " + $item</lang>
Nim
<lang nim>import strutils, rdstdin
proc menu(xs: openArray[string]) =
for i, x in xs: echo " ", i, ") ", x
proc ok(reply: string; count: Positive): bool =
try: let n = parseInt(reply) return 0 <= n and n < count except: return false
proc selector(xs: openArray[string]; prompt: string): string =
if xs.len == 0: return "" var reply = "-1" while not ok(reply, xs.len): menu(xs) reply = readLineFromStdin(prompt).strip() return xs[parseInt(reply)]
const xs = ["fee fie", "huff and puff", "mirror mirror", "tick tock"] let item = selector(xs, "Which is from the three pigs: ") echo "You chose: ", item</lang>
- Output:
0) fee fie 1) huff and puff 2) mirror mirror 3) tick tock Which is from the three pigs: foo 0) fee fie 1) huff and puff 2) mirror mirror 3) tick tock Which is from the three pigs: 4 0) fee fie 1) huff and puff 2) mirror mirror 3) tick tock Which is from the three pigs: 2 You chose: mirror mirror
OCaml
<lang ocaml> let select ?(prompt="Choice? ") = function
| [] -> "" | choices -> let rec menu () = List.iteri (Printf.printf "%d: %s\n") choices; print_string prompt; try List.nth choices (read_int ()) with _ -> menu () in menu ()
</lang>
Example use in the REPL: <lang ocaml>
- select ["fee fie"; "huff and puff"; "mirror mirror"; "tick tock"];;
0: fee fie 1: huff and puff 2: mirror mirror 3: tick tock Choice? 2 - : string = "mirror mirror" </lang>
OpenEdge/Progress
<lang progress>FUNCTION bashMenu RETURNS CHAR(
i_c AS CHAR
):
DEF VAR ii AS INT. DEF VAR hfr AS HANDLE. DEF VAR hmenu AS HANDLE EXTENT. DEF VAR ikey AS INT. DEF VAR ireturn AS INT INITIAL ?.
EXTENT( hmenu ) = NUM-ENTRIES( i_c ).
CREATE FRAME hfr ASSIGN WIDTH = 80 HEIGHT = NUM-ENTRIES( i_c ) PARENT = CURRENT-WINDOW VISIBLE = TRUE .
DO ii = 1 TO NUM-ENTRIES( i_c ):
CREATE TEXT hmenu ASSIGN FRAME = hfr FORMAT = "x(79)" SCREEN-VALUE = SUBSTITUTE( "&1. &2", ii, ENTRY( ii, i_c ) ) ROW = ii VISIBLE = TRUE . END.
IF i_c = "" THEN ireturn = 1.
DO WHILE ireturn = ?:
READKEY. ikey = INTEGER( CHR( LASTKEY ) ) NO-ERROR. IF ikey >= 1 AND ikey <= NUM-ENTRIES( i_c ) THEN ireturn = ikey.
END.
RETURN ENTRY( ireturn, i_c ).
END FUNCTION.
MESSAGE
bashMenu( "fee fie,huff and puff,mirror mirror,tick tock" )
VIEW-AS ALERT-BOX.</lang>
Oz
<lang oz>declare
fun {Select Prompt Items} case Items of nil then "" else
for Item in Items Index in 1..{Length Items} do {System.showInfo Index#") "#Item} end {System.printInfo Prompt} try {Nth Items {ReadInt}} catch _ then {Select Prompt Items} end
end end
fun {ReadInt} class TextFile from Open.file Open.text end StdIo = {New TextFile init(name:stdin)} in {String.toInt {StdIo getS($)}} end Item = {Select "Which is from the three pigs: "
["fee fie" "huff and puff" "mirror mirror" "tick tock"]}
in
{System.showInfo "You chose: "#Item}</lang>
PARI/GP
<lang parigp>choose(v)=my(n);for(i=1,#v,print(i". "v[i]));while(type(n=input())!="t_INT"|n>#v|n<1,);v[n] choose(["fee fie","huff and puff","mirror mirror","tick tock"])</lang>
Pascal
Tested with Free Pascal 2.6.4 (arm). <lang pascal>program Menu; {$ASSERTIONS ON} uses
objects;
var
MenuItems :PUnSortedStrCollection; selected :string;
Function SelectMenuItem(MenuItems :PUnSortedStrCollection):string; var
i, idx :integer; code :word; choice :string;
begin
// Return empty string if the collection is empty. if MenuItems^.Count = 0 then begin SelectMenuItem := ; Exit; end;
repeat for i:=0 to MenuItems^.Count-1 do begin writeln(i+1:2, ') ', PString(MenuItems^.At(i))^); end; write('Make your choice: '); readln(choice); // Try to convert choice to an integer. // Code contains 0 if this was successful. val(choice, idx, code) until (code=0) and (idx>0) and (idx<=MenuItems^.Count); // Return the selected element. SelectMenuItem := PString(MenuItems^.At(idx-1))^;
end;
begin
// Create an unsorted string collection for the menu items. MenuItems := new(PUnSortedStrCollection, Init(10, 10));
// Add some menu items to the collection. MenuItems^.Insert(NewStr('fee fie')); MenuItems^.Insert(NewStr('huff and puff')); MenuItems^.Insert(NewStr('mirror mirror')); MenuItems^.Insert(NewStr('tick tock'));
// Display the menu and get user input. selected := SelectMenuItem(MenuItems); writeln('You chose: ', selected);
dispose(MenuItems, Done);
// Test function with an empty collection. MenuItems := new(PUnSortedStrCollection, Init(10, 10));
selected := SelectMenuItem(MenuItems); // Assert that the function returns an empty string. assert(selected = , 'Assertion failed: the function did not return an empty string.');
dispose(MenuItems, Done);
end.</lang>
- Output:
$ bin/menu 1) fee fie 2) huff and puff 3) mirror mirror 4) tick tock Make your choice: abc 1) fee fie 2) huff and puff 3) mirror mirror 4) tick tock Make your choice: 99 1) fee fie 2) huff and puff 3) mirror mirror 4) tick tock Make your choice: 3 You chose: mirror mirror
Perl
<lang perl>sub menu {
my ($prompt,@array) = @_; return unless @array;
print " $_: $array[$_]\n" for(0..$#array); print $prompt; $n = <>; return $array[$n] if $n =~ /^\d+$/ and defined $array[$n]; return &menu($prompt,@array);
}
@a = ('fee fie', 'huff and puff', 'mirror mirror', 'tick tock'); $prompt = 'Which is from the three pigs: ';
$a = &menu($prompt,@a);
print "You chose: $a\n";</lang>
Phix
<lang Phix>function menu_select(sequence items, object prompt) sequence res = ""
items = remove_all("",items) if length(items)!=0 then while 1 do for i=1 to length(items) do printf(1,"%d) %s\n",{i,items[i]}) end for puts(1,iff(atom(prompt)?"Choice?":prompt)) res = scanf(trim(gets(0)),"%d") puts(1,"\n") if length(res)=1 then integer nres = res[1][1] if nres>0 and nres<=length(items) then res = items[nres] exit end if end if end while end if return res
end function
constant items = {"fee fie", "huff and puff", "mirror mirror", "tick tock"} constant prompt = "Which is from the three pigs? " string res = menu_select(items,prompt) printf(1,"You chose %s.\n",{res})</lang>
PHP
<lang php><?php $stdin = fopen("php://stdin", "r"); $allowed = array(1 => 'fee fie', 'huff and puff', 'mirror mirror', 'tick tock');
for(;;) {
foreach ($allowed as $id => $name) { echo " $id: $name\n"; } echo "Which is from the four pigs: "; $stdin_string = fgets($stdin, 4096); if (isset($allowed[(int) $stdin_string])) { echo "You chose: {$allowed[(int) $stdin_string]}\n"; break; }
}</lang>
PicoLisp
<lang PicoLisp>(de choose (Prompt Items)
(use N (loop (for (I . Item) Items (prinl I ": " Item) ) (prin Prompt " ") (flush) (NIL (setq N (in NIL (read)))) (T (>= (length Items) N 1) (prinl (get Items N))) ) ) )
(choose "Which is from the three pigs?"
'("fee fie" "huff and puff" "mirror mirror" "tick tock") )</lang>
- Output:
1: fee fie 2: huff and puff 3: mirror mirror 4: tick tock Which is from the three pigs? q 1: fee fie 2: huff and puff 3: mirror mirror 4: tick tock Which is from the three pigs? 5 1: fee fie 2: huff and puff 3: mirror mirror 4: tick tock Which is from the three pigs? 2 huff and puff
PL/I
<lang PL/I>
test: proc options (main);
declare menu(4) character(100) varying static initial (
'fee fie', 'huff and puff', 'mirror mirror', 'tick tock');
declare (i, k) fixed binary;
do i = lbound(menu,1) to hbound(menu,1);
put skip edit (trim(i), ': ', menu(i) ) (a);
end; put skip list ('please choose an item number'); get list (k); if k >= lbound(menu,1) & k <= hbound(menu,1) then
put skip edit ('you chose ', menu(k)) (a);
else
put skip list ('Could not find your phrase');
end test; </lang>
PowerShell
<lang PowerShell> function Select-TextItem {
<# .SYNOPSIS Prints a textual menu formatted as an index value followed by its corresponding string for each object in the list. .DESCRIPTION Prints a textual menu formatted as an index value followed by its corresponding string for each object in the list; Prompts the user to enter a number; Returns an object corresponding to the selected index number. .PARAMETER InputObject An array of objects. .PARAMETER Prompt The menu prompt string. .EXAMPLE “fee fie”, “huff and puff”, “mirror mirror”, “tick tock” | Select-TextItem .EXAMPLE “huff and puff”, “fee fie”, “tick tock”, “mirror mirror” | Sort-Object | Select-TextItem -Prompt "Select a string" .EXAMPLE Select-TextItem -InputObject (Get-Process) .EXAMPLE (Get-Process | Where-Object {$_.Name -match "notepad"}) | Select-TextItem -Prompt "Select a Process" | Stop-Process -ErrorAction SilentlyContinue #> [CmdletBinding()] Param ( [Parameter(Mandatory=$true, ValueFromPipeline=$true)] $InputObject,
[Parameter(Mandatory=$false)] [string] $Prompt = "Enter Selection" )
Begin { $menuOptions = @() } Process { $menuOptions += $InputObject } End { if(!$inputObject){ return "" } do { [int]$optionNumber = 1
foreach ($option in $menuOptions) { Write-Host ("{0,3}: {1}" -f $optionNumber,$option)
$optionNumber++ }
Write-Host ("{0,3}: {1}" -f 0,"To cancel")
$choice = Read-Host $Prompt
$selectedValue = ""
if ($choice -gt 0 -and $choice -le $menuOptions.Count) { $selectedValue = $menuOptions[$choice - 1] }
} until ($choice -match "^[0-9]+$" -and ($choice -eq 0 -or $choice -le $menuOptions.Count))
return $selectedValue }
}
“fee fie”, “huff and puff”, “mirror mirror”, “tick tock” | Select-TextItem -Prompt "Select a string" </lang>
- Output:
1: fee fie 2: huff and puff 3: mirror mirror 4: tick tock 0: To cancel Select a string: 3 mirror mirror
ProDOS
<lang>
- a
printline ==========MENU========== printline 1. Fee Fie printline 2. Huff Puff printline 3. Mirror, Mirror printline 4. Tick, Tock editvar /newvar /value=a /userinput=1 /title=What page do you want to go to? if -a- /hasvalue 1 printline You chose a line from the book Jack and the Beanstalk. & exitcurrentprogram 1 if -a- /hasvalue 2 printline You chose a line from the book The Three Little Pigs. & exitcurrentprogram 1 if -a- /hasvalue 3 printline You chose a line from the book Snow White. & exitcurrentprogram 1 if -a- /hasvalue 4 printline You chose a line from the book Beauty and the Beast. & exitcurrentprogram 1 printline You either chose an invalid choice or didn't chose. editvar /newvar /value=goback /userinput=1 /title=Do you want to chose something else? if -goback- /hasvalue y goto :a else exitcurrentprogram 1 </lang>
Prolog
<lang prolog> rosetta_menu([], "") :- !. %% Incase of an empty list. rosetta_menu(Items, SelectedItem) :-
repeat, %% Repeat until everything that follows is true. display_menu(Items), %% IO get_choice(Choice), %% IO number(Choice), %% True if Choice is a number. nth1(Choice, Items, SelectedItem), %% True if SelectedItem is the 1-based nth member of Items, (fails if Choice is out of range) !.
display_menu(Items) :-
nl, foreach( nth1(Index, Items, Item), format('~w) ~s~n', [Index, Item]) ).
get_choice(Choice) :-
prompt1('Select a menu item by number:'), read(Choice).
</lang>
Example run:
<lang prolog> ?- rosetta_menu(["fee fie", "huff and puff", "mirror mirror", "tick tock"], String).
1) fee fie 2) huff and puff 3) mirror mirror 4) tick tock Select a menu item by number:a.
1) fee fie 2) huff and puff 3) mirror mirror 4) tick tock Select a menu item by number:10.
1) fee fie 2) huff and puff 3) mirror mirror 4) tick tock Select a menu item by number:3. String = "mirror mirror". </lang>
PureBasic
<lang PureBasic>If OpenConsole()
Define i, txt$, choice Dim txts.s(4) EnableGraphicalConsole(1) ;- Enable graphical mode in the console Repeat ClearConsole() Restore TheStrings ; Set reads address For i=1 To 4 Read.s txt$ txts(i)=txt$ ConsoleLocate(3,i): Print(Str(i)+": "+txt$) Next ConsoleLocate(3,6): Print("Your choice? ") choice=Val(Input()) Until choice>=1 And choice<=4 ClearConsole() ConsoleLocate(3,2): Print("You chose: "+txts(choice)) ; ;-Now, wait for the user before ending to allow a nice presentation ConsoleLocate(3,5): Print("Press ENTER to quit"): Input()
EndIf End
DataSection
TheStrings: Data.s "fee fie", "huff And puff", "mirror mirror", "tick tock"
EndDataSection</lang>
Python
<lang python>def _menu(items):
for indexitem in enumerate(items): print (" %2i) %s" % indexitem)
def _ok(reply, itemcount):
try: n = int(reply) return 0 <= n < itemcount except: return False
def selector(items, prompt):
'Prompt to select an item from the items' if not items: return reply = -1 itemcount = len(items) while not _ok(reply, itemcount): _menu(items) # Use input instead of raw_input for Python 3.x reply = raw_input(prompt).strip() return items[int(reply)]
if __name__ == '__main__':
items = ['fee fie', 'huff and puff', 'mirror mirror', 'tick tock'] item = selector(items, 'Which is from the three pigs: ') print ("You chose: " + item)</lang>
Sample runs:
0) fee fie 1) huff and puff 2) mirror mirror 3) tick tock Which is from the three pigs: -1 0) fee fie 1) huff and puff 2) mirror mirror 3) tick tock Which is from the three pigs: 0 You chose: fee fie >>> ================================ RESTART ================================ >>> 0) fee fie 1) huff and puff 2) mirror mirror 3) tick tock Which is from the three pigs: 4 0) fee fie 1) huff and puff 2) mirror mirror 3) tick tock Which is from the three pigs: 3 You chose: tick tock
R
Uses menu. <lang R>showmenu <- function(choices = NULL) {
if (is.null(choices)) return("") ans <- menu(choices) if(ans==0) "" else choices[ans]
} str <- showmenu(c("fee fie", "huff and puff", "mirror mirror", "tick tock")) str <- showmenu() </lang>
Racket
<lang Racket>
- lang racket
(define (menu choices)
(cond [(null? choices) ""] [else (for ([c choices] [i (in-naturals 1)]) (printf "~a. ~a\n" i c)) (printf "Enter a number: ") (define n (string->number (read-line))) (or (and (exact-integer? n) (<= 1 n (length choices)) (list-ref choices (sub1 n))) (menu choices))]))
(menu '("fee fie" "huff and puff" "mirror mirror" "tick tock")) </lang>
Sample Run:
1. fee fie 2. huff and puff 3. mirror mirror 4. tick tock Enter a number: three 1. fee fie 2. huff and puff 3. mirror mirror 4. tick tock Enter a number: help 1. fee fie 2. huff and puff 3. mirror mirror 4. tick tock Enter a number: 3!! 1. fee fie 2. huff and puff 3. mirror mirror 4. tick tock Enter a number: 3 "mirror mirror"
Raku
(formerly Perl 6) <lang perl6>sub menu ( $prompt, @items ) {
return unless @items.elems; repeat until my $selection ~~ /^ \d+ $/ && @items[--$selection] { my $i = 1; say " {$i++}) $_" for @items; $selection = prompt $prompt; } return @items[$selection];
}
my @choices = 'fee fie', 'huff and puff', 'mirror mirror', 'tick tock'; my $prompt = 'Enter the number corresponding to your selection: ';
my $answer = menu( $prompt, [] ); say "You chose: $answer" if $answer.chars;
$answer = menu( $prompt, @choices ); say "You chose: $answer" if $answer.chars;</lang>
REBOL
<lang REBOL>REBOL [ Title: "Text Menu" URL: http://rosettacode.org/wiki/Select ]
choices: ["fee fie" "huff and puff" "mirror mirror" "tick tock"] choice: ""
valid?: func [ choices [block! list! series!] choice ][ if error? try [choice: to-integer choice] [return false] all [0 < choice choice <= length? choices] ]
while [not valid? choices choice][ repeat i length? choices [print [" " i ":" choices/:i]] choice: ask "Which is from the three pigs? " ] print ["You chose:" pick choices to-integer choice]</lang>
Output:
1 : fee fie 2 : huff and puff 3 : mirror mirror 4 : tick tock Which is from the three pigs? klf 1 : fee fie 2 : huff and puff 3 : mirror mirror 4 : tick tock Which is from the three pigs? 5 1 : fee fie 2 : huff and puff 3 : mirror mirror 4 : tick tock Which is from the three pigs? 2 You chose: huff and puff
Red
<lang Red>Red ["text menu"]
menu: function [items][ print either empty? items [""] [until [ repeat n length? items [print [n ":" items/:n]] attempt [pick items to-integer ask "Your choice: "] ]] ]</lang>
- Output:
>> menu ["fee fie" "huff and puff" "mirror mirror" "tick tock"] 1 : fee fie 2 : huff and puff 3 : mirror mirror 4 : tick tock Your choice: azerty 1 : fee fie 2 : huff and puff 3 : mirror mirror 4 : tick tock Your choice: 7 1 : fee fie 2 : huff and puff 3 : mirror mirror 4 : tick tock Your choice: 3 mirror mirror >> menu [] >>
REXX
<lang rexx>/*REXX program displays a list, then prompts the user for a selection number (integer).*/
do forever /*keep prompting until response is OK. */ call list_create /*create the list from scratch. */ call list_show /*display (show) the list to the user.*/ if #==0 then return /*if list is empty, then return null.*/ say right(' choose an item by entering a number from 1 ───►' #, 70, '═') parse pull x /*get the user's choice (if any). */
select when x= then call sayErr "a choice wasn't entered" when words(x)\==1 then call sayErr 'too many choices entered:' when \datatype(x,'N') then call sayErr "the choice isn't numeric:" when \datatype(x,'W') then call sayErr "the choice isn't an integer:" when x<1 | x># then call sayErr "the choice isn't within range:" otherwise leave /*this leaves the DO FOREVER loop.*/ end /*select*/ end /*forever*/ /*user might've entered 2. or 003 */
x=x/1 /*normalize the number (maybe). */ say; say 'you chose item' x": " #.x return #.x /*stick a fork in it, we're all done. */ /*──────────────────────────────────────────────────────────────────────────────────────*/ list_create: #.1= 'fee fie' /*this is one method for list-building.*/
#.2= 'huff and puff' #.3= 'mirror mirror' #.4= 'tick tock' #=4 /*store the number of choices in # */ return /*(above) is just one convention. */
/*──────────────────────────────────────────────────────────────────────────────────────*/ list_show: say /*display a blank line. */
do j=1 for # /*display the list of choices. */ say '[item' j"] " #.j /*display item number with its choice. */ end /*j*/ say /*display another blank line. */ return
/*──────────────────────────────────────────────────────────────────────────────────────*/ sayErr: say; say '***error***' arg(1) x; say; return</lang>
- output (which includes what the user entered):
[item 1] fee fie [item 2] huff and puff [item 3] mirror mirror [item 4] tick tock ════════════════════ choose an item by entering a number from 1 ───► 4 2 ◄■■■■■■■■■■■■■■■■■■■■■■ what the user entered at the terminal. you chose item 2: huff and puff
Ring
<lang ring> aList = ["fee fie", "huff and puff", "mirror mirror", "tick tock"] selected = menu(aList, "please make a selection: ") see "" + selected + nl
func menu aList, prompt
ndex = 1 while index>0 and index<=len(aList) for index = 1 to len(aList) if aList[index]!="" see "" + index + " : " + aList[index] + " " ok next see nl see prompt give select index = number(select) see "" + aList[index] + nl if select!=string(index) index = -1 ok if index>=0 if index<=len(aList) if aList[index]="" index = -1 ok ok ok end return aList[index]
</lang> Output:
1 : fee fie 2 : huff and puff 3 : mirror mirror 4 : tick tock please make a selection: 2 huff and puff 1 : fee fie 2 : huff and puff 3 : mirror mirror 4 : tick tock please make a selection: 1 fee fie 1 : fee fie 2 : huff and puff 3 : mirror mirror 4 : tick tock please make a selection: 4 tick tock 1 : fee fie 2 : huff and puff 3 : mirror mirror 4 : tick tock please make a selection: 3 mirror mirror
Ruby
<lang ruby> def select(prompt, items = [])
if items.empty? else answer = -1 until (0...items.length).cover?(answer) items.each_with_index {|i,j| puts "#{j}. #{i}"} print "#{prompt}: " begin answer = Integer(gets) rescue ArgumentError redo end end items[answer] end
end
- test empty list
response = select('Which is empty') puts "empty list returns: >#{response}<\n"
- "real" test
items = ['fee fie', 'huff and puff', 'mirror mirror', 'tick tock'] response = select('Which is from the three pigs', items) puts "you chose: >#{response}<" </lang>
Run BASIC
<lang runbasic>dim choose$(5) choose$(1) = "1 Fee Fie" choose$(2) = "2 Huff Puff" choose$(3) = "3 Mirror, Mirror" choose$(4) = "4 Tick, Tock" choose$(5) = "Exit"
[start] print "Menu Selection" listbox #lb,choose$(),5 button #sel, "Accept",[select] wait
[select] selected$=#lb selection$() print " " if selected$<>"" then
print "You selected ";selected$ else print "No selection made"
end if
button #con, "Continue",[go2]
wait [go2] if selected$<>"Exit" then
cls goto [start] else cls end
end if</lang>
Rust
<lang rust> fn menu_select<'a>(items: &'a [&'a str]) -> &'a str {
if items.len() == 0 { return ""; }
let stdin = std::io::stdin(); let mut buffer = String::new();
loop { for (i, item) in items.iter().enumerate() { println!("{}) {}", i + 1, item); } print!("Pick a number from 1 to {}: ", items.len());
// Read the user input: stdin.read_line(&mut buffer).unwrap(); println!();
if let Ok(selected_index) = buffer.trim().parse::<usize>() { if 0 < selected_index { if let Some(selected_item) = items.get(selected_index - 1) { return selected_item; } } }
// The buffer will contain the old input, so we need to clear it before we can reuse it. buffer.clear(); }
}
fn main() {
// Empty list: let selection = menu_select(&[]); println!("No choice: {:?}", selection);
// List with items: let items = [ "fee fie", "huff and puff", "mirror mirror", "tick tock", ];
let selection = menu_select(&items); println!("You chose: {}", selection);
} </lang>
Scala
Scala idiom (Functional)
<lang>import scala.util.Try
object Menu extends App {
val choice = menu(list)
def menu(menuList: Seq[String]): String = { if (menuList.isEmpty) "" else { val n = menuList.size
def getChoice: Try[Int] = { println("\n M E N U\n") menuList.zipWithIndex.map { case (text, index) => s"${index + 1}: $text" }.foreach(println(_)) print(s"\nEnter your choice 1 - $n : ") Try { io.StdIn.readInt() } }
menuList(Iterator.continually(getChoice) .dropWhile(p => p.isFailure || !(1 to n).contains(p.get)) .next.get - 1) } }
def list = Seq("fee fie", "huff and puff", "mirror mirror", "tick tock")
println(s"\nYou chose : $choice")
}</lang>
Seed7
<lang seed7>$ include "seed7_05.s7i";
const func string: menuSelect (in array string: items, in string: prompt) is func
result var string: selection is ""; local var string: item is ""; var integer: index is 0; var integer: num is 0; begin if length(items) <> 0 then repeat for item key index range items do writeln(index <& ". " <& item); end for; write(prompt); readln(num); until num >= 1 and num <= length(items); selection := items[num]; end if end func;
const array string: items is [] ("fee fie", "huff and puff", "mirror mirror", "tick tock"); const string: prompt is "Which is from the three pigs? ";
const proc: main is func
begin writeln("You chose " <& menuSelect(items, prompt)); end func;</lang>
Sidef
<lang ruby>func menu (prompt, arr) {
arr.len > 0 || return loop { for i in ^arr { say " #{i}: #{arr[i]}" } var n = Sys.scanln(prompt) \\ return() n ~~ /^[0-9]+\z/ ? Num(n) : next arr.exists(n) && return arr[n] }
}
var list = ['fee fie', 'huff and puff', 'mirror mirror', 'tick tock'] var prompt = 'Please choose an item number: '
var answer = menu(prompt, list) say "You choose: #{answer}"</lang>
Swift
<lang swift>func getMenuInput(selections: [String]) -> String {
guard !selections.isEmpty else { return "" }
func printMenu() { for (i, str) in selections.enumerated() { print("\(i + 1)) \(str)") }
print("Selection: ", terminator: "") }
while true { printMenu()
guard let input = readLine(strippingNewline: true), !input.isEmpty else { return "" }
guard let n = Int(input), n > 0, n <= selections.count else { continue }
return selections[n - 1] }
}
let selected = getMenuInput(selections: [
"fee fie", "huff and puff", "mirror mirror", "tick tock"
])
print("You chose: \(selected)")</lang>
Tcl
<lang tcl>proc select {prompt choices} {
set nc [llength $choices] if {!$nc} {
return ""
} set numWidth [string length $nc] while true {
set i 0 foreach s $choices { puts [format " %-*d: %s" $numWidth [incr i] $s] } puts -nonewline "$prompt: " flush stdout gets stdin num if {[string is int -strict $num] && $num >= 1 && $num <= $nc} { incr num -1 return [lindex $choices $num] }
}
}</lang> Testing it out interactively... <lang tcl>% puts >[select test {}]< >< % puts >[select "Which is from the three pigs" {
"fee fie" "huff and puff" "mirror mirror" "tick tock"
}]<
1: fee fie 2: huff and puff 3: mirror mirror 4: tick tock
Which is from the three pigs: 0
1: fee fie 2: huff and puff 3: mirror mirror 4: tick tock
Which is from the three pigs: skdfjhgz
1: fee fie 2: huff and puff 3: mirror mirror 4: tick tock
Which is from the three pigs:
1: fee fie 2: huff and puff 3: mirror mirror 4: tick tock
Which is from the three pigs: 5
1: fee fie 2: huff and puff 3: mirror mirror 4: tick tock
Which is from the three pigs: 2 >huff and puff<</lang>
TI-83 BASIC
TI-83 BASIC does not support lists of strings, so this works by accepting a string containing an arbitrary number of items separated by colons. If you want to use a different delimiter, change the colons on lines 2, 3, 6 and 7 to your symbol of choice.
The calculator's screen isn't big enough to display more than 7 (9 on the new C Silver Edition and CE calcs) options at a time, so the display scrolls to accommodate options if necessary. You won't be able to see options that have scrolled off the top of the screen, but they're still accessible from the input.
Although TI-BASIC can handle empty strings, there's no way to give it one through the Input function, so it doesn't have to worry about being "called with an empty list."
Input "",Str1 //input as ITEM 1:ITEM 2:ITEM 3... ":"+Str1+":→Str1 Σ(sub(Str1,X,1)=":",X,1,length(Str1→X 0→dim(L₁ For(Z,2,length(Str1 inString(Str1,":",Z-1 1+Ans+.01inString(Str1,":",Ans+1→L₁(1+dim(L₁ ᴇ2fPart(Ans→Z End seq(iPart(L₁(X))+.01(ᴇ2fPart(L₁(X))-iPart(L₁(X))),X,1,dim(L₁→L₁ Repeat A>0 and A<X ClrHome For(Z,1,dim(L₁ Disp " :"+sub(Str1,iPart(L₁(Z)),ᴇ2fPart(L₁(Z Output(min(7,Z),1+(Z≤7),Z End Input A End Disp sub(Str1,iPart(L₁(A)),ᴇ2fPart(L₁(A
Output with FEE FIE:HUFF AND PUFF:MIRROR MIRROR:TICK TOCK
<lang> 1:FEE FIE
2:HUFF AND PUFF 3:MIRROR MIRROR 4:TICK TOCK
? [flashing cursor]</lang>
The language also has a Menu( command, but it doesn't really follow the requirements for the challenge (only up to 7 options allowed, no user input, option is selected using the arrow keys instead of by entering a number, etc)
"FEE FIE→Str0 "HUFF AND PUFF→Str1 "MIRROR MIRROR→Str2 "TICK TOCK→Str3 Menu("CHOOSE",Str0,A,Str1,B,Str2,C,Str3,D) Lbl A Disp Str0 Return Lbl B Disp Str1 Return Lbl C Disp Str2 Return Lbl D Disp Str3
UNIX Shell
This example uses the Bash select statement, but Bash did not invent this feature. The select loop comes originally from the Korn Shell, and appears in some other shells. This loop always continues to read menu choices until the script breaks the loop, or the standard input reaches end of file (EOF).
- If the user enters a blank line, the select loop repeats the list of choices. This is the only way to print the list again. An invalid choice only repeats the prompt, not the list.
Our choose function wraps a select loop. This wrapper implements the task requirement to provide an empty string from an empty list of choices. It also breaks the select loop after the first good choice.
<lang bash># choose 'choice 1' 'choice 2' ...
- Prints menu to standard error. Prompts with PS3.
- Reads REPLY from standard input. Sets CHOICE.
choose() {
CHOICE= # Default CHOICE is empty string. $# -gt 0 || return # Return if "$@" is empty. select CHOICE; do # Select from "$@". if -n $CHOICE ; then break else echo Invalid choice. fi done
}
PS3='Which is from the three pigs: ' choose 'fee fie' 'huff and puff' 'mirror mirror' 'tick tock' -n $CHOICE && echo You chose: $CHOICE -z $CHOICE && echo No input.</lang>
$ bash menu.sh 1) fee fie 2) huff and puff 3) mirror mirror 4) tick tock Which is from the three pigs: 5 Invalid choice. Which is from the three pigs: 2 You chose: huff and puff $
$ zsh menu.sh 1) fee fie 2) huff and puff 3) mirror mirror 4) tick tock Which is from the three pigs: 2 You chose: huff and puff
es
There is no select loop, but this es script provides just enough code to mimic one.
- Deviation from task: When the list of choices is empty, this function returns an empty list, not an empty string.
<lang es># choose 'choice 1' 'choice 2' ...
- Prints menu to standard error. Prompts with $prompt.
- Returns choice. If no input, returns empty list.
fn choose args { # If args are empty, return empty list. ~ $#args 0 && return
# Echo to standard error. let (reply =; choice =; fn-menu =; fn-ch =) >[1=2] { fn-menu = { # Show menu. let (i = 1) for (c = $args) { echo $i') '$c i = `{expr $i + 1} } } fn-ch = { # Set choice = $args($reply), but ignore error # if $reply is not a valid index. choice = <={catch @ e {result} { result $args($reply) }} }
menu forever { # Show prompt, read reply. echo -n $prompt reply = <={%read}
# If no input, return empty list. ~ $#reply 0 && return
# Parse reply and return choice. reply = <={%split \ \t\n $reply} if {~ $#reply 0} { # Empty reply: show menu again. menu } {~ $#reply 1 && ch; ~ $#choice 1} { return $choice } { echo Invalid choice. } } } }
let (choice = <={ local (prompt = 'Which is from the three pigs: ') choose 'fee fie' 'huff and puff' 'mirror mirror' 'tick tock' }) { ~ $#choice 1 && echo You chose: $choice ~ $#choice 0 && echo No input. }</lang>
$ es menu.es 1) fee fie 2) huff and puff 3) mirror mirror 4) tick tock Which is from the three pigs: 2 You chose: huff and puff
Ursa
<lang ursa>def _menu (string<> items) for (decl int i) (< i (size items)) (inc i) out " " i ") " items endl console end for end _menu
def _ok (string reply, int itemcount) try decl int n set n (int reply) return (and (or (> n 0) (= n 0)) (< n itemcount)) catch return false end try end _ok
def selector (string<> items, string prompt) # Prompt to select an item from the items if (= (size items) 0) return "" end if decl int itemcount reply set reply -1 set itemcount (size items) while (not (_ok reply itemcount)) _menu items out prompt console set reply (in int console) end while return items<(int reply)> end selector
decl string<> items append "fee fie" "huff and puff" "mirror mirror" "tick tock" items decl string item set item (selector items "Which is from the three pigs: ") out "You chose: " item endl console</lang>
VBScript
<lang vb>'The Function Function Menu(ArrList, Prompt)
Select Case False 'Non-standard usage hahaha Case IsArray(ArrList) Menu = "" 'Empty output string for non-arrays Exit Function Case UBound(ArrList) >= LBound(ArrList) Menu = "" 'Empty output string for empty arrays Exit Function End Select 'Display menu and prompt Do While True For i = LBound(ArrList) To UBound(ArrList) WScript.StdOut.WriteLine((i + 1) & ". " & ArrList(i)) Next WScript.StdOut.Write(Prompt) Choice = WScript.StdIn.ReadLine 'Check if input is valid If IsNumeric(Choice) Then 'Check for numeric-ness If CStr(CLng(Choice)) = Choice Then 'Check for integer-ness (no decimal part) Index = Choice - 1 'Arrays are 0-based 'Check if Index is in array If LBound(ArrList) <= Index And Index <= UBound(ArrList) Then Exit Do End If End If End If WScript.StdOut.WriteLine("Invalid choice.") Loop Menu = ArrList(Index)
End Function
'The Main Thing Sample = Array("fee fie", "huff and puff", "mirror mirror", "tick tock") InputText = "Which is from the three pigs: " WScript.StdOut.WriteLine("Output: " & Menu(Sample, InputText))</lang>
- Output:
C:\>cscript /nologo menu.vbs 1. fee fie 2. huff and puff 3. mirror mirror 4. tick tock Which is from the three pigs: cdsfklfm Invalid choice. 1. fee fie 2. huff and puff 3. mirror mirror 4. tick tock Which is from the three pigs: -2 Invalid choice. 1. fee fie 2. huff and puff 3. mirror mirror 4. tick tock Which is from the three pigs: 3.14159 Invalid choice. 1. fee fie 2. huff and puff 3. mirror mirror 4. tick tock Which is from the three pigs: 45 Invalid choice. 1. fee fie 2. huff and puff 3. mirror mirror 4. tick tock Which is from the three pigs: 2 Output: huff and puff
Wren
<lang ecmascript>import "/ioutil" for Input
var menu = Fn.new { |list|
var n = list.count if (n == 0) return "" var prompt = "\n M E N U\n\n" for (i in 0...n) prompt = prompt + "%(i+1). %(list[i])\n" prompt = prompt + "\nEnter your choice (1 - %(n)): " var index = Input.integer(prompt, 1, n) return list[index-1]
}
var list = ["fee fie", "huff and puff", "mirror mirror", "tick tock"] var choice = menu.call(list) System.print("\nYou chose : %(choice)")</lang>
- Output:
Sample run:
M E N U 1. fee fie 2. huff and puff 3. mirror mirror 4. tick tock Enter your choice (1 - 4): 6 Must be an integer between 1 and 4, try again. M E N U 1. fee fie 2. huff and puff 3. mirror mirror 4. tick tock Enter your choice (1 - 4): m Must be an integer between 1 and 4, try again. M E N U 1. fee fie 2. huff and puff 3. mirror mirror 4. tick tock Enter your choice (1 - 4): 4 You chose : tick tock
XPL0
<lang XPL0>string 0;
func Menu(List); int List; int Size, I, C; [Size:= List(0); if Size < 1 then return List(0); \if empty list, return pointer to 0 for I:= 1 to Size-1 do
[IntOut(0, I); Text(0, ": "); Text(0, List(I)); CrLf(0); ];
CrLf(0); Text(0, List(Size)); \display prompt loop [C:= ChIn(0); \buffered keyboard requires Enter key
if C>=^1 & C<=Size-1+^0 then return List(C-^0); Text(0, "Please enter 1 thru "); IntOut(0, Size-1); Text(0, ": "); ];
];
Text(0, Menu([5, "fee fie", "huff and puff", "mirror mirror", "tick tock",
"Which phrase is from the Three Little Pigs? "]))</lang>
Example output:
1: fee fie 2: huff and puff 3: mirror mirror 4: tick tock Which phrase is from the Three Little Pigs? 5 Please enter 1 thru 4: 2 huff and puff
zkl
<lang zkl>fcn teleprompter(options){
os:=T("exit").extend(vm.arglist); N:=os.len(); if(N==1) return(""); while(1){ Utils.zipWith(fcn(n,o){"%d) %s".fmt(n,o).println()},[0..],os); a:=ask("Your choice: "); try{ n:=a.toInt(); if(0<=n<N) return(os[n]); } catch{} println("Ack, not good"); }
}
teleprompter("fee fie" , "huff and puff" , "mirror mirror" , "tick tock") .println();</lang>
- Output:
0) exit 1) fee fie 2) huff and puff 3) mirror mirror 4) tick tock Your choice: abc Ack, not good 0) exit 1) fee fie 2) huff and puff 3) mirror mirror 4) tick tock Your choice: 3 mirror mirror
- Programming Tasks
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