1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
|
#include "tree_fragment.h"
#include <cassert>
using namespace std;
namespace cdec {
TreeFragment::TreeFragment(const string& tree, bool allow_frontier_sites) {
int bal = 0;
const unsigned len = tree.size();
unsigned cur = 0;
unsigned open = 0, close = 0;
for (auto& c : tree) {
++cur;
if (c == '(') { ++open; ++bal; }
else if (c == ')') {
++close; --bal;
if (bal < 1 && cur != len) {
cerr << "Badly formed tree detected at column " << cur << " in:\n" << tree << endl;
abort();
}
}
}
nodes.resize(open);
unsigned cp = 0, symp = 0, np = 0;
ParseRec(tree, allow_frontier_sites, cp, symp, np, &cp, &symp, &np);
root = nodes.back().lhs;
//cerr << "ROOT: " << TD::Convert(root & ALL_MASK) << endl;
//DebugRec(open - 1, &cerr); cerr << "\n";
}
void TreeFragment::DebugRec(unsigned cur, ostream* out) const {
*out << '(' << TD::Convert(nodes[cur].lhs & ALL_MASK);
for (auto& x : nodes[cur].rhs) {
*out << ' ';
if (IsFrontier(x)) {
*out << '[' << TD::Convert(x & ALL_MASK) << ']';
} else if (IsRHS(x)) {
DebugRec(x & ALL_MASK, out);
} else { // must be terminal
*out << TD::Convert(x);
}
}
*out << ')';
}
// cp is the character index in the tree
// np keeps track of the nodes (nonterminals) that have been built
// symp keeps track of the terminal symbols that have been built
void TreeFragment::ParseRec(const string& tree, bool afs, unsigned cp, unsigned symp, unsigned np, unsigned* pcp, unsigned* psymp, unsigned* pnp) {
if (tree[cp] != '(') {
cerr << "Expected ( at " << cp << endl;
abort();
}
const unsigned i = symp;
vector<unsigned> rhs; // w | 0 = terminal, w | NT_BIT, index | FRONTIER_BIT
++cp;
while(tree[cp] == ' ') { ++cp; }
const unsigned nt_start = cp;
while(tree[cp] != ' ' && tree[cp] != '(' && tree[cp] != ')') { ++cp; }
const unsigned nt_end = cp;
while(tree[cp] == ' ') { ++cp; }
while (tree[cp] != ')') {
if (tree[cp] == '(') {
// recursively call parser to deal with constituent
ParseRec(tree, afs, cp, symp, np, &cp, &symp, &np);
unsigned ind = np - 1;
rhs.push_back(ind | RHS_BIT);
} else { // deal with terminal / nonterminal substitution
++symp;
assert(tree[cp] != ' ');
const unsigned t_start = cp;
while(tree[cp] != ' ' && tree[cp] != ')' && tree[cp] != '(') { ++cp; }
const unsigned t_end = cp;
while(tree[cp] == ' ') { ++cp; }
// TODO: add a terminal symbol to the current edge
const bool is_terminal = tree[t_start] != '[' || (t_end - t_start < 3 || tree[t_end - 1] != ']');
if (is_terminal) {
const unsigned term = TD::Convert(tree.substr(t_start, t_end - t_start));
rhs.push_back(term);
// cerr << "T='" << TD::Convert(term) << "'\n";
++terminals;
} else { // frontier site (NT but no recursion)
const unsigned nt = TD::Convert(tree.substr(t_start + 1, t_end - t_start - 2)) | FRONTIER_BIT;
rhs.push_back(nt);
++frontier_sites;
// cerr << "FRONT-NT=[" << TD::Convert(nt & ALL_MASK) << "]\n";
if (!afs) {
cerr << "Frontier sites not allowed in input: " << tree << endl;
abort();
}
}
}
} // continuent has completed, cp is at ), build node
const unsigned j = symp; // span from (i,j)
// add an internal non-terminal symbol
const unsigned nt = TD::Convert(tree.substr(nt_start, nt_end - nt_start)) | RHS_BIT;
nodes[np] = TreeFragmentProduction(nt, rhs);
//cerr << np << " production(" << i << "," << j << ")= " << TD::Convert(nt & ALL_MASK) << " -->";
//for (auto& x : rhs) {
// cerr << ' ';
// if (IsFrontier(x)) cerr << '*';
// if (IsInternalNT(x)) cerr << TD::Convert(nodes[x & ALL_MASK].lhs & ALL_MASK); else
// cerr << TD::Convert(x & ALL_MASK);
//}
//cerr << "\n "; DebugRec(np,&cerr); cerr << endl;
++cp;
while(tree[cp] == ' ' && cp < tree.size()) { ++cp; }
*pcp = cp;
*pnp = np + 1;
*psymp = symp;
}
}
|
