nixmodule.lua

--====================================================================--
--[ HELP                                                             ]--
--====================================================================--

--[[
showMenu(displayed: table or string, returns: table,
  allowNil: boolean or string or nil): function
  Shows a menu.

  Parameters:
  - displayed: A string or table of strings. If a string is provided,
    that string is displayed. If a table is provided, the strings are
    displayed one per line.
  - returns: A table of key-value pairs. The value should refer to a
    return value, and the key is the user input choice that causes that
    value to be returned. All keys should be lowercase, as user input
    will be converted to lowercase as well.
  - allowNil: A string or the boolean "true" that, if true, will allow
    the function to return nil when an invalid choice is made, instead
    of looping and requiring a valid response. If a string, it is the
    message displayed when an invalid response is returned by the user.
    If not provided, defaults to "Please pick a choice above!".

  Returns: The function
]]--

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--[ EXAMPLE CODE                                                     ]--
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--[[
-- showMenu ------------------------------------------------------------
display = {"Here's a menu!",
           "1 = print Hello World",
           "2 = print Goodbye",
           "text = print Creative!"}
values = {"Hello World", --1
          "Goodbye", --2
          text="Creative!",
          secret="You found my secrets! o:"}
print(showMenu(display, values))

-- end of examples ---------------------------------------------------]]

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--[ FUNCTIONS                                                        ]--
--====================================================================--

local function showMenu(displayed, values, allowNil)
  allowNil = allowNil or "Please pick an option above."

  if type(displayed) == "string" then
    displayed = {displayed}
  end

  for a = 1, #displayed do
    print(displayed[a])
  end

  loop = true

  while loop do
    choice = term.read():lower()
    result = values[choice]
    if result ~= nil or allowNil == true then loop = false
    else print(allowNil) end
  end

  return result
end

t = require("term")

--====================================================================--
--[ This makes this a module                                         ]--
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local Module = {
  showMenu = showMenu
}

return Module