.. index:: Auxiliary modules; Symbol table

SymbolTable
-----------

The symbol table stores which *symbols* have been defined in the program (in ASL, that is
just variable and function names) and associates each symbol with a *type* in ``TypeMgr``.

The symbol table is also able to handle visibility scopes, so we can have separate tables for
separate functions, or stacked tables for nested scopes.

Thus, class ``SymTable`` stores which symbols have been defined in each scope, and we can
query it about which is the *type* of symbol, whether a symbol is defined in the current
function, or (if it is defined twice because there is a nested scope) which is the definition
we should use at each moment.

.. literalinclude:: ../../../practica/common/SymTable.h
   :language: c++
   :linenos:
   :lines: 45-120,222