gcc/et-forest.h

   1 /* Et-forest data structure implementation.
   2    Copyright (C) 2002, 2003, 2004, 2005, 2007, 2010
   3    Free Software Foundation, Inc.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; see the file COPYING3.  If not see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 /* This package implements ET forest data structure. Each tree in
  20    the structure maintains a tree structure and offers logarithmic time
  21    for tree operations (insertion and removal of nodes and edges) and
  22    poly-logarithmic time for nearest common ancestor.
  23
  24    ET tree stores its structure as a sequence of symbols obtained
  25    by dfs(root)
  26
  27    dfs (node)
  28    {
  29      s = node;
  30      for each child c of node do
  31        s = concat (s, c, node);
  32      return s;
  33    }
  34
  35    For example for tree
  36
  37             1
  38           / | \
  39          2  3  4
  40        / |
  41       4  5
  42
  43    the sequence is 1 2 4 2 5 3 1 3 1 4 1.
  44
  45    The sequence is stored in a slightly modified splay tree.
  46    In order to support various types of node values, a hashtable
  47    is used to convert node values to the internal representation.  */
  48
  49 #ifndef _ET_TREE_H
  50 #define _ET_TREE_H
  51
  52 #ifdef __cplusplus
  53 extern "C" {
  54 #endif /* __cplusplus */
  55
  56 /* The node representing the node in an et tree.  */
  57 struct et_node
  58 {
  59   void *data;                   /* The data represented by the node.  */
  60
  61   int dfs_num_in, dfs_num_out;  /* Number of the node in the dfs ordering.  */
  62
  63   struct et_node *father;       /* Father of the node.  */
  64   struct et_node *son;          /* The first of the sons of the node.  */
  65   struct et_node *left;
  66   struct et_node *right;        /* The brothers of the node.  */
  67
  68   struct et_occ *rightmost_occ; /* The rightmost occurrence.  */
  69   struct et_occ *parent_occ;    /* The occurrence of the parent node.  */
  70 };
  71
  72 struct et_node *et_new_tree (void *data);
  73 void et_free_tree (struct et_node *);
  74 void et_free_tree_force (struct et_node *);
  75 void et_free_pools (void);
  76 void et_set_father (struct et_node *, struct et_node *);
  77 void et_split (struct et_node *);
  78 struct et_node *et_nca (struct et_node *, struct et_node *);
  79 bool et_below (struct et_node *, struct et_node *);
  80 struct et_node *et_root (struct et_node *);
  81
  82 #ifdef __cplusplus
  83 }
  84 #endif /* __cplusplus */
  85
  86 #endif /* _ET_TREE_H */