Comments

#!/usr/local/bin/lua
--
-- Single line comment
--[[ Multi line
comment ]]
--[====[ Multi line
comment ]====]

Strings

""
"Foo\"bar"
"Foo\
bar \z
baz"
''
'Foo\'bar'
'Foo\
bar \z
baz'
[[Multi "line"
string]]
[==[Multi [["line"]]
string]==]

Numbers

3
345
0xff
0xBEBADA
3, 3., 3.1, .3,
3e12, 3.e-41, 3.1E+1, .3e1
0x0.1E
0xA23p-4
0X1.921FB54442D18P+1

Full example

function To_Functable(t, fn)
  return setmetatable(t,
    {
     __index = function(t, k) return fn(k) end,
     __call = function(t, k) return t[k] end
    })
end

-- Functable bottles of beer implementation

spell_out = {
  "One", "Two", "Three", "Four", "Five",
  "Six", "Seven", "Eight", "Nine", "Ten",
  [0] = "No more",
  [-1] = "Lots more"
}

spell_out = To_Functable(spell_out, function(i) return i end)

bottles = To_Functable({"Just one bottle of beer"},
                       function(i)
                         return spell_out(i) .. " bottles of beer"
                       end)

function line1(i)
  return bottles(i) .. " on the wall, " .. bottles(i) .. "\n"
end

line2 = To_Functable({[0] = "Go to the store, Buy some more,\n"},
                     function(i)
                       return "Take one down and pass it around,\n"
                     end)

function line3(i)
  return bottles(i) .. " on the wall.\n"
end

function song(n)
  for i = n, 0, -1 do
    io.write(line1(i), line2(i), line3(i - 1), "\n")
  end
end