This type provides 64-bits (not 63, like int); also on 32-bit
architectures. It should be used instead of int for all values
that may exceed 32-bits to ensure that everything works fine
for the 32-bit port of Opa.
this duplicate the parser in two flavours:
-the classic syntax (current light syntax)
-the new js like syntax (try to look like js in better :)
and it introduces the first draft of the new syntax (by Quentin)