This is a Lua-specific construct. The syntax `table.function` and `table:function`...

This is a Lua-specific construct. The syntax table.function and table:function indicates two different ways to call a function in Lua, and they behave differently in terms of how they pass the arguments. Here's the breakdown:

Basics

1. table.function

   • This syntax refers to directly accessing (and possibly calling) a function from the table.
   • When you call the function like this — table.function(...) — you need to explicitly pass the table (or any other required arguments) as an argument, i.e., the function does not automatically take the table as its self.
   • It is equivalent to table["function"].

2. table:function

   • This syntax is a method-call shorthand in Lua.
   • It is equivalent to calling table.function but with an implicit "self" parameter. Essentially, it translates to table.function(table, ...).
   • When you define a function as table:function, internally it receives self as the first parameter.

Example

-- Define a table
table = {}

-- Define a function directly
function table.sayHello()
    print("Hello!")
end

-- Define a method with "self" (colon syntax)
function table:speak(message)
    print(self) -- self represents the table here
    print(message)
end

-- Calling with dot-notation
table.sayHello()   -- OUTPUT: Hello!

-- Colon-notation implicitly passes `self`
table:speak("Hi!") -- OUTPUT: table (printed by 'self')
                   --         Hi!

-- Dot-notation requires passing `self` manually for methods
table.speak(table, "Hi!") -- OUTPUT: table
                          --         Hi!

When Does It Matter?

• Use table.function when:

  • The function does not need access to the table it is defined in.
  • You are manually passing the self parameter or other arguments.

• Use table:function when:

  • The function is a method intended to operate on the table, and you want self to be automatically passed as the first parameter.

Key Difference:

• table.function is a standard function call.
• table:function adds the self argument to the function call automatically.

This difference becomes very important when designing object-oriented behavior in Lua or when functions depend on their parent table.