Type sections
=============

Example:

.. code-block:: nim
  type # example demonstrating mutually recursive types
    Node = ref NodeObj # a traced pointer to a NodeObj
    NodeObj = object
      le, ri: Node     # left and right subtrees
      sym: ref Sym     # leaves contain a reference to a Sym

    Sym = object       # a symbol
      name: string     # the symbol's name
      line: int        # the line the symbol was declared in
      code: Node       # the symbol's abstract syntax tree

A type section begins with the ``type`` keyword. It contains multiple
type definitions. A type definition binds a type to a name. Type definitions
can be recursive or even mutually recursive. Mutually recursive types are only
possible within a single ``type`` section. Nominal types like ``objects``
or ``enums`` can only be defined in a ``type`` section.