/TeXmacs-1.0.7.11-src/src/Data/Tree/tree_modify.cpp

 1
 2/******************************************************************************
 3* MODULE     : tree_modify.cpp
 4* DESCRIPTION: high level tree modification subroutines
 5* COPYRIGHT  : (C) 2010  Joris van der Hoeven
 6*******************************************************************************
 7* This software falls under the GNU general public license version 3 or later.
 8* It comes WITHOUT ANY WARRANTY WHATSOEVER. For details, see the file LICENSE
 9* in the root directory or <http://www.gnu.org/licenses/gpl-3.0.html>.
10******************************************************************************/
11
12#include "tree_modify.hpp"
13#include "drd_std.hpp"
14#include "path.hpp"
15
16extern tree the_et;
17
18/******************************************************************************
19* DRD-based correction of trees
20******************************************************************************/
21
22void
23correct_concat_node (tree& t, int done) {
24  //cout << "Correct " << t << ", " << done << "\n";
25  int i, n= N(t);
26  if (n == 0) {
27    assign (t, "");
28    return;
29  }
30  for (i=done; i<n; i++) {
31    if (t[i] == "") {
32      remove (t, i, 1);
33      correct_concat_node (t, i);
34      return;
35    }
36    if ((i<n-1) && is_atomic (t[i]) && is_atomic (t[i+1])) {
37      join (t, i);
38      correct_concat_node (t, i);
39      return;
40    }
41    if (is_concat (t[i])) {
42      insert_node (t, 0, CONCAT);
43      split (t, 0, i);
44      split (t, 1, 1);
45      remove_node (t[1], 0);
46      if (t[0] == tree (CONCAT)) remove (t, 0, 1);
47      else join (t, 0);
48      if (t[1] == tree (CONCAT)) remove (t, 1, 1);
49      else join (t, 0);
50      remove_node (t, 0);
51      correct_concat_node (t, max (i-1, 0));
52      return;
53    }    
54  }
55}
56
57void
58correct_node (tree& t) {
59  // NOTE: this routine should only modify t and its descendants,
60  // but not any ancestors
61  if (is_compound (t)) {
62    if (the_drd->contains (as_string (L(t))) &&
63	!the_drd->correct_arity (L(t), N(t)))
64      assign (t, "");
65    if (is_concat (t))
66      correct_concat_node (t, 0);
67  }
68}
69
70void
71correct_downwards (tree& t) {
72  if (is_compound (t))
73    for (int i=0; i<N(t); i++)
74      correct_downwards (t[i]);
75  correct_node (t);
76}
77
78void
79correct_upwards (tree& t) {
80  correct_node (t);
81  path ip= obtain_ip (t);
82  if (ip_attached (ip) && !is_nil (ip))
83    correct_upwards (subtree (the_et, reverse (ip->next)));
84}