Many language implementations come with an interactive mode.

This is a command-line interpreter that reads lines from the user and evaluates these lines as statements or expressions.

An interactive mode may also be known as a command mode,   a read-eval-print loop (REPL),   or a shell.



Task

Show how to start this mode.

Then, as a small example of its use, interactively create a function of two strings and a separator that returns the strings separated by two concatenated instances of the separator   (the 3rd argument).



Example

             f('Rosetta',  'Code',  ':')   

should return

             'Rosetta::Code'               



Note

This task is   not   about creating your own interactive mode.




$ pike
Pike v7.8 release 352 running Hilfe v3.5 (Incremental Pike Frontend)
> string f(string first, string second, string sep){
>>   return(first + sep + sep + second);
>> }
> f("Rosetta","Code",":");
(1) Result: "Rosetta::Code"
>