RosettaCodeData/Task/Interactive-programming/Lua/interactive-programming.lua

$ lua
Lua 5.1.2  Copyright (C) 1994-2007 Lua.org, PUC-Rio
> function conc(a, b, c)
>> return a..c..c..b
>> end
> print(conc("Rosetta", "Code", ":"))
Rosetta::Code
>