add support for internal tree structure on SCFG rules

1 files changed, 87 insertions, 0 deletions

diff --git a/decoder/tree2string_translator.cc b/decoder/tree2string_translator.cc
new file mode 100644
index 00000000..4ccc54e2
--- /dev/null
+++ b/decoder/tree2string_translator.cc
@@ -0,0 +1,87 @@
+#include <algorithm>
+#include <vector>
+#include <boost/functional/hash.hpp>
+#include <unordered_map>
+#include "tree_fragment.h"
+#include "translator.h"
+#include "hg.h"
+#include "sentence_metadata.h"
+#include "filelib.h"
+#include "stringlib.h"
+#include "tdict.h"
+#include "verbose.h"
+
+using namespace std;
+
+// root: S
+// A          implication: (S [A] *INCOMPLETE*
+// B          implication: (S [A] [B] *INCOMPLETE*
+// *0*        implication: (S _[A] [B])
+// a          implication: (S (A a *INCOMPLETE* [B])
+// a          implication: (S (A a a *INCOMPLETE* [B])
+// *0*        implication: (S (A a a) _[B])
+// D          implication: (S (A a a) (B [D] *INCOMPLETE*)
+// *0*        implication: (S (A a a) (B _[D]))
+// d          implication: (S (A a a) (B (D d *INCOMPLETE*))
+// *0*        implication: (S (A a a) (B (D d)))
+// --there are no further outgoing links possible--
+
+// root: S
+// A          implication: (S [A] *INCOMPLETE*
+// B          implication: (S [A] [B] *INCOMPLETE*
+// *0*        implication: (S _[A] [B])
+// *0*        implication: (S [A] _[B])
+// b          implication: (S [A] (B b *INCOMPLETE*))
+struct Tree2StringGrammarNode {
+  unordered_map<unsigned, Tree2StringGrammarNode> next;
+  string rules;
+};
+
+void ReadTree2StringGrammar(istream* in, unordered_map<unsigned, Tree2StringGrammarNode>* proots) {
+  unordered_map<unsigned, Tree2StringGrammarNode>& roots = *proots;
+  string line;
+  while(getline(*in, line)) {
+    size_t pos = line.find("|||");
+    assert(pos != string::npos);
+    assert(pos > 3);
+    if (line[pos - 1] == ' ') --pos;
+    cdec::TreeFragment rule_src(line.substr(0, pos), true);
+  }
+}
+
+struct Tree2StringTranslatorImpl {
+  unordered_map<unsigned, Tree2StringGrammarNode> roots; // root['S'] gives rule network for S rules
+  Tree2StringTranslatorImpl(const boost::program_options::variables_map& conf) {
+    ReadFile rf(conf["grammar"].as<vector<string>>()[0]);
+    ReadTree2StringGrammar(rf.stream(), &roots);
+  }
+  bool Translate(const string& input,
+                 SentenceMetadata* smeta,
+                 const vector<double>& weights,
+                 Hypergraph* minus_lm_forest) {
+    cdec::TreeFragment input_tree(input, false);
+    cerr << "Tree2StringTranslatorImpl: please implement this!\n";
+    return false;
+  }
+};
+
+Tree2StringTranslator::Tree2StringTranslator(const boost::program_options::variables_map& conf) :
+  pimpl_(new Tree2StringTranslatorImpl(conf)) {}
+
+bool Tree2StringTranslator::TranslateImpl(const string& input,
+                               SentenceMetadata* smeta,
+                               const vector<double>& weights,
+                               Hypergraph* minus_lm_forest) {
+  return pimpl_->Translate(input, smeta, weights, minus_lm_forest);
+}
+
+void Tree2StringTranslator::ProcessMarkupHintsImpl(const map<string, string>& kv) {
+}
+
+void Tree2StringTranslator::SentenceCompleteImpl() {
+}
+
+std::string Tree2StringTranslator::GetDecoderType() const {
+  return "tree2string";
+}
+