1 // sequence_node.hpp
2 // Copyright (c) 2007-2009 Ben Hanson (http://www.benhanson.net/)
3 //
4 // Distributed under the Boost Software License, Version 1.0. (See accompanying
5 // file licence_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
6 #ifndef BOOST_SPIRIT_SUPPORT_DETAIL_LEXER_PARSER_TREE_SEQUENCE_NODE_HPP
7 #define BOOST_SPIRIT_SUPPORT_DETAIL_LEXER_PARSER_TREE_SEQUENCE_NODE_HPP
8 
9 #include "node.hpp"
10 
11 namespace boost
12 {
13 namespace lexer
14 {
15 namespace detail
16 {
17 class sequence_node : public node
18 {
19 public:
sequence_node(node * left_,node * right_)20     sequence_node (node *left_, node *right_) :
21         node (left_->nullable () && right_->nullable ()),
22         _left (left_),
23         _right (right_)
24     {
25         _left->append_firstpos (_firstpos);
26 
27         if (_left->nullable ())
28         {
29             _right->append_firstpos (_firstpos);
30         }
31 
32         if (_right->nullable ())
33         {
34             _left->append_lastpos (_lastpos);
35         }
36 
37         _right->append_lastpos (_lastpos);
38 
39         node_vector &lastpos_ = _left->lastpos ();
40         const node_vector &firstpos_ = _right->firstpos ();
41 
42         for (node_vector::iterator iter_ = lastpos_.begin (),
43             end_ = lastpos_.end (); iter_ != end_; ++iter_)
44         {
45             (*iter_)->append_followpos (firstpos_);
46         }
47     }
48 
~sequence_node()49     virtual ~sequence_node ()
50     {
51     }
52 
what_type() const53     virtual type what_type () const
54     {
55         return SEQUENCE;
56     }
57 
traverse(const_node_stack & node_stack_,bool_stack & perform_op_stack_) const58     virtual bool traverse (const_node_stack &node_stack_,
59         bool_stack &perform_op_stack_) const
60     {
61         perform_op_stack_.push (true);
62 
63         switch (_right->what_type ())
64         {
65         case SEQUENCE:
66         case SELECTION:
67         case ITERATION:
68             perform_op_stack_.push (false);
69             break;
70         default:
71             break;
72         }
73 
74         node_stack_.push (_right);
75         node_stack_.push (_left);
76         return true;
77     }
78 
79 private:
80     // Not owner of these pointers...
81     node *_left;
82     node *_right;
83 
copy_node(node_ptr_vector & node_ptr_vector_,node_stack & new_node_stack_,bool_stack & perform_op_stack_,bool & down_) const84     virtual void copy_node (node_ptr_vector &node_ptr_vector_,
85         node_stack &new_node_stack_, bool_stack &perform_op_stack_,
86         bool &down_) const
87     {
88         if (perform_op_stack_.top ())
89         {
90             node *rhs_ = new_node_stack_.top ();
91 
92             new_node_stack_.pop ();
93 
94             node *lhs_ = new_node_stack_.top ();
95 
96             node_ptr_vector_->push_back (static_cast<sequence_node *>(0));
97             node_ptr_vector_->back () = new sequence_node (lhs_, rhs_);
98             new_node_stack_.top () = node_ptr_vector_->back ();
99         }
100         else
101         {
102             down_ = true;
103         }
104 
105         perform_op_stack_.pop ();
106     }
107 };
108 }
109 }
110 }
111 
112 #endif
113