expr_logical_or.cpp

// CSS Preprocessor
// Copyright (c) 2015-2019  Made to Order Software Corp.  All Rights Reserved
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

/** \file
 * \brief Implementation of the CSS Preprocessor expression.
 *
 * The CSS Preprocessor expression class is used to reduce a list
 * of nodes by applying expressions to the various values.
 *
 * \sa \ref expression_rules
 */

#include "csspp/expression.h"

#include "csspp/exceptions.h"
#include "csspp/parser.h"
#include "csspp/unicode_range.h"

#include <algorithm>
#include <cmath>
#include <iostream>

namespace csspp
{

node::pointer_t expression::logical_or()
{
    // logical_or: logical_and
    //           | logical_or IDENTIFIER (='or') logical_and
    //           | logical_or '||' logical_and

    node::pointer_t result(logical_and());
    if(!result)
    {
        return node::pointer_t();
    }

    while((f_current->is(node_type_t::IDENTIFIER) && f_current->get_string() == "or")
       || f_current->is(node_type_t::COLUMN))
    {
        position pos(f_current->get_position());

        // skip the OR
        next();

        node::pointer_t rhs(logical_and());
        if(!rhs)
        {
            return node::pointer_t();
        }

        // apply the OR
        bool const lr(boolean(result));
        bool const rr(boolean(rhs));
        result.reset(new node(node_type_t::BOOLEAN, pos));
        result->set_boolean(lr || rr);
    }

    return result;
}

} // namespace csspp

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// mode: cpp
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