Variables
=========

Hurdy variables work just as in Lua (can be global or local) and are scoped in the same way. However, unlike Lua,
Hurdy does not default to global variables, bur rather requires variables to be *explicitly* declared as either local
or global before they can be assigned to. The compiler will give an error if a variable is assigned to without declaring it first.

.. note::
  This restriction only applies when assigning to variables. For all other cases they don't need to be declared and if they have not
  been declared as local in the current scope they will be treated as free names and accessed from the current environment.

Local variables
---------------

Local variables are declared with the :code:`var` keyword, and follow the regular rules of local variables in Lua.

.. code-block:: hurdy

  var x -- declare variable, can be assigned to later
  x = 2

  var y = 5 -- declare and assign at the same time

  var z = print -- this works even if print has not been declared

  {
    var w = true -- w is only defined in here
  }

  w = false -- compiler will give an error, whas not been declared in scope

The Lua code corresponding to

.. code-block:: hurdy

  var x
  x = 2

  var y = 5

is

.. code-block:: lua

  local x
  x = 2

  local y = 5

Just as in Lua, redaclaring a local variable shadows the previous definition within the current scope.

Multiple local variables can be declared/assigned to simoultaneously like in Lua:

.. code-block:: hurdy

  var x, y = 1, 2, 3
  var w, z

corresponds to the Lua code

.. code-block:: lua

  local x, y = 1, 2, 3
  local w, z



Global variables
----------------

Global variables are declared using the :code:`global` keyword, and can *only be declared if the identifier is not already local in the current scope*.

.. code-block:: hurdy

  global x -- declare variable, can be assigned to later
  x = 2

  global y = 5 -- declare and assign at the same time

  var z = 3
  global z -- compiler will give an error, z is already local in scope

  {
    var w = true -- w is only defined in here
  }

  global w -- this is fine, w is not in scope

Multiple global variables can be declared/assigned to simoultaneously like in Lua:

.. code-block:: hurdy

  global x, y = 1, 2, 3
  global w, z