**************************************************************************
*                                                                        *
*  Menhir                                                                *
*                                                                        *
*  Franois Pottier and Yann Rgis-Gianas, INRIA Rocquencourt            *
*                                                                        *
*  Copyright 2005 Institut National de Recherche en Informatique et      *
*  en Automatique. All rights reserved. This file is distributed         *
*  under the terms of the Q Public License version 1.0, with the         *
*  change described in file LICENSE.                                     *
*                                                                        *
**************************************************************************

In this variant of the calc demo, the parser's semantic actions are
parameterized over a structure, called [Semantics], which defines how numbers
should be interpreted. The parser is later instantiated with floating-point
numbers, so the calculator actually performs floating-point evaluation -- but
the grammar specification is independent of this detail.
