-- regular function

function sayHello (recipient)
    print('Hello, '..recipient)
end

sayHello('Roberto')




-- anonymous function (exactly the same as above)

local sayHello = function (recipient)
    print('Hello, '..recipient)
end




-- function on an object

local cat = {}

function cat.sayHello ()
    print('Meow')
end

cat.sayHello();




-- self-executing anonymous function

(function (recipient)
    print('Hello, '..recipient)        --> Hello Luiz
end)('Luiz')




-- Multiple return values

function getCoordinates()
    return 12, 55, 123
end

local x, y, z = getCoordinates()
print(x, y, z)                     --> 12  55  123




-- varargs

function sayAllsorts(...)
    print(...)
end

sayAllsorts('Lua', 5.1, 'on the Web')   --> Lua 5.1 on the Web




-- mix 'n' match varargs

function tail (h, ...)
    return ...
end

print(tail (1, 2 ,3))      --> 2, 3




-- function calls that pass either a single string or single object don't
-- require brackets

print 'Hello, Waldemar'
print { foo = 'bar' }




-- functions are first class objects

function doStuffWithAThing (thing, ...)
    thing (...)
end

doStuffWithAThing(print, 1, 2, 3)

a = {}
doStuffWithAThing(table.insert, a, 'moo')
print(a[1])





-- the colon is just syntatic sugar

local cat = { name = 'Ruby', food = 'Felix' }

function cat.getName (self)     -- there is no such thing as "self", you have to
                                -- provide it
    return self.name
end

print(cat.getName(cat))         -- pass the cat in

-- use a colon instead and Lua will automatically pass what's before the colon
-- as the first argument
print(cat:getName())            -- this is exactly the same as the previous call


-- better still, you can clean up that function definition with a colon too; Lua
-- will automatically add a "self" parameter at the front
function cat:getFood ()         -- there is no such thing as "self", you have to
                                -- provide it
    return self.food
end

print(cat:getFood())
print(cat.getFood(cat))     -- both these calls are the same.