parser/tree/sequence_node.hpp

0001 // sequence_node.hpp
0002 // Copyright (c) 2007-2009 Ben Hanson (http://www.benhanson.net/)
0003 //
0004 // Distributed under the Boost Software License, Version 1.0. (See accompanying
0005 // file licence_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0006 #ifndef BOOST_SPIRIT_SUPPORT_DETAIL_LEXER_PARSER_TREE_SEQUENCE_NODE_HPP
0007 #define BOOST_SPIRIT_SUPPORT_DETAIL_LEXER_PARSER_TREE_SEQUENCE_NODE_HPP
0008
0009 #include "node.hpp"
0010
0011 namespace boost
0012 {
0013 namespace lexer
0014 {
0015 namespace detail
0016 {
0017 class sequence_node : public node
0018 {
0019 public:
0020     sequence_node (node *left_, node *right_) :
0021         node (left_->nullable () && right_->nullable ()),
0022         _left (left_),
0023         _right (right_)
0024     {
0025         _left->append_firstpos (_firstpos);
0026
0027         if (_left->nullable ())
0028         {
0029             _right->append_firstpos (_firstpos);
0030         }
0031
0032         if (_right->nullable ())
0033         {
0034             _left->append_lastpos (_lastpos);
0035         }
0036
0037         _right->append_lastpos (_lastpos);
0038
0039         node_vector &lastpos_ = _left->lastpos ();
0040         const node_vector &firstpos_ = _right->firstpos ();
0041
0042         for (node_vector::iterator iter_ = lastpos_.begin (),
0043             end_ = lastpos_.end (); iter_ != end_; ++iter_)
0044         {
0045             (*iter_)->append_followpos (firstpos_);
0046         }
0047     }
0048
0049     virtual ~sequence_node ()
0050     {
0051     }
0052
0053     virtual type what_type () const
0054     {
0055         return SEQUENCE;
0056     }
0057
0058     virtual bool traverse (const_node_stack &node_stack_,
0059         bool_stack &perform_op_stack_) const
0060     {
0061         perform_op_stack_.push (true);
0062
0063         switch (_right->what_type ())
0064         {
0065         case SEQUENCE:
0066         case SELECTION:
0067         case ITERATION:
0068             perform_op_stack_.push (false);
0069             break;
0070         default:
0071             break;
0072         }
0073
0074         node_stack_.push (_right);
0075         node_stack_.push (_left);
0076         return true;
0077     }
0078
0079 private:
0080     // Not owner of these pointers...
0081     node *_left;
0082     node *_right;
0083
0084     virtual void copy_node (node_ptr_vector &node_ptr_vector_,
0085         node_stack &new_node_stack_, bool_stack &perform_op_stack_,
0086         bool &down_) const
0087     {
0088         if (perform_op_stack_.top ())
0089         {
0090             node *rhs_ = new_node_stack_.top ();
0091
0092             new_node_stack_.pop ();
0093
0094             node *lhs_ = new_node_stack_.top ();
0095
0096             node_ptr_vector_->push_back (static_cast<sequence_node *>(0));
0097             node_ptr_vector_->back () = new sequence_node (lhs_, rhs_);
0098             new_node_stack_.top () = node_ptr_vector_->back ();
0099         }
0100         else
0101         {
0102             down_ = true;
0103         }
0104
0105         perform_op_stack_.pop ();
0106     }
0107 };
0108 }
0109 }
0110 }
0111
0112 #endif