add support for internal tree structure on SCFG rules

3 files changed, 176 insertions, 12 deletions

diff --git a/decoder/rule_lexer.ll b/decoder/rule_lexer.ll
index c6a85919..05963d05 100644
--- a/decoder/rule_lexer.ll
+++ b/decoder/rule_lexer.ll
@@ -12,6 +12,7 @@
 #include "fdict.h"
 #include "trule.h"
 #include "verbose.h"
+#include "tree_fragment.h"
 
 int lex_line = 0;
 std::istream* scfglex_stream = NULL;
@@ -51,6 +52,7 @@ int scfglex_src_nts[MAX_ARITY];
 // float scfglex_nt_size_vars[MAX_ARITY];
 std::stack<TRulePtr> ctf_rule_stack;
 unsigned int ctf_level = 0;
+boost::shared_ptr<cdec::TreeFragment> scfglex_tree;
 
 #define MAX_ALS 2000
 AlignmentPoint scfglex_als[MAX_ALS];
@@ -120,7 +122,7 @@ void check_and_update_ctf_stack(const TRulePtr& rp) {
 REAL [\-+]?[0-9]+(\.[0-9]*([eE][-+]*[0-9]+)?)?|inf|[\-+]inf
 NT [^\t \[\],]+
 
-%x LHS_END SRC TRG FEATS FEATVAL ALIGNS
+%x LHS_END SRC TRG FEATS FEATVAL ALIGNS TREE
 %%
 
 <INITIAL>[ \t]	{
@@ -205,7 +207,13 @@ NT [^\t \[\],]+
 		++scfglex_src_rhs_size;
 		}
 <SRC>[ \t]+	{ ; }
-
+<TREE>[^|\n]+	{
+                if (yyleng > 0) {
+		  int len = yyleng;
+                  while(len > 1 && yytext[len - 1] != ')') { --len; }
+                  scfglex_tree.reset(new cdec::TreeFragment(std::string(yytext, len), true));
+                }
+		}
 <TRG>\|\|\|	{
 		BEGIN(FEATS);
 		}
@@ -216,7 +224,7 @@ NT [^\t \[\],]+
 		}
 <TRG>[ \t]+	{ ; }
 
-<TRG,FEATS,ALIGNS>\n	{
+<TRG,FEATS,ALIGNS,TREE>\n	{
                 if (scfglex_src_arity != scfglex_trg_arity) {
                   std::cerr << "Grammar " << scfglex_fname << " line " << lex_line << ": LHS and RHS arity mismatch!\n";
                   abort();
@@ -224,18 +232,25 @@ NT [^\t \[\],]+
 		// const bool ignore_grammar_features = false;
 		// if (ignore_grammar_features) scfglex_num_feats = 0;
 		TRulePtr rp(new TRule(scfglex_lhs, scfglex_src_rhs, scfglex_src_rhs_size, scfglex_trg_rhs, scfglex_trg_rhs_size, scfglex_feat_ids, scfglex_feat_vals, scfglex_num_feats, scfglex_src_arity, scfglex_als, scfglex_num_als));
-    check_and_update_ctf_stack(rp);
-    TRulePtr coarse_rp = ((ctf_level == 0) ? TRulePtr() : ctf_rule_stack.top());
+		if (scfglex_tree) {
+		  if (scfglex_tree->frontier_sites != rp->Arity()) {
+		    std::cerr << "Arity mismatch with tree annotation: " << *scfglex_tree << std::endl;
+		    abort();
+		  }
+		  rp->tree_structure.swap(scfglex_tree);
+		}
+		check_and_update_ctf_stack(rp);
+		TRulePtr coarse_rp = ((ctf_level == 0) ? TRulePtr() : ctf_rule_stack.top());
 		rule_callback(rp, ctf_level, coarse_rp, rule_callback_extra);
-    ctf_rule_stack.push(rp);
+		ctf_rule_stack.push(rp);
 		// std::cerr << rp->AsString() << std::endl;
 		num_rules++;
-    lex_line++;
-    if (!SILENT) {
-      if (num_rules %   50000 == 0) { std::cerr << '.' << std::flush; fl = true; }
-      if (num_rules % 2000000 == 0) { std::cerr << " [" << num_rules << "]\n"; fl = false; }
-    }
-    ctf_level = 0;
+		lex_line++;
+		if (!SILENT) {
+		  if (num_rules %   50000 == 0) { std::cerr << '.' << std::flush; fl = true; }
+		  if (num_rules % 2000000 == 0) { std::cerr << " [" << num_rules << "]\n"; fl = false; }
+		}
+		ctf_level = 0;
 		BEGIN(INITIAL);
 		}
 
@@ -253,6 +268,9 @@ NT [^\t \[\],]+
 <FEATS>\|\|\|	{
 		BEGIN(ALIGNS);
 		}
+<ALIGNS>\|\|\|[ \t]*	{
+		BEGIN(TREE);
+		}
 <FEATVAL>{REAL}	{
 		scfglex_feat_vals[scfglex_num_feats] = strtod(yytext, NULL);
 		++scfglex_num_feats;
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";
+}
+
diff --git a/decoder/tree_fragment.h b/decoder/tree_fragment.h
new file mode 100644
index 00000000..83cd1c1e
--- /dev/null
+++ b/decoder/tree_fragment.h
@@ -0,0 +1,59 @@
+#ifndef TREE_FRAGMENT
+#define TREE_FRAGMENT
+
+#include <iostream>
+#include <vector>
+#include <string>
+
+#include "tdict.h"
+
+namespace cdec {
+
+static const unsigned NT_BIT       = 0x40000000u;
+static const unsigned FRONTIER_BIT = 0x80000000u;
+static const unsigned ALL_MASK     = 0x0FFFFFFFu;
+
+inline bool IsInternalNT(unsigned x) {
+  return (x & NT_BIT);
+}
+
+inline bool IsFrontier(unsigned x) {
+  return (x & FRONTIER_BIT);
+}
+
+struct TreeFragmentProduction {
+  TreeFragmentProduction() {}
+  TreeFragmentProduction(int nttype, const std::vector<unsigned>& r) : lhs(nttype), rhs(r) {}
+  unsigned lhs;
+  std::vector<unsigned> rhs;
+};
+
+// this data structure represents a tree or forest
+// productions can have mixtures of terminals and nonterminal symbols and non-terminal frontier sites
+class TreeFragment {
+ public:
+  TreeFragment() : frontier_sites(), terminals() {}
+  // (S (NP a (X b) c d) (VP (V foo) (NP (NN bar))))
+  explicit TreeFragment(const std::string& tree, bool allow_frontier_sites = false);
+  void DebugRec(unsigned cur, std::ostream* out) const;
+ private:
+  // 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 ParseRec(const std::string& tree, bool afs, unsigned cp, unsigned symp, unsigned np, unsigned* pcp, unsigned* psymp, unsigned* pnp);
+ public:
+  unsigned root;
+  unsigned char frontier_sites;
+  unsigned short terminals;
+
+  std::vector<TreeFragmentProduction> nodes;
+};
+
+inline std::ostream& operator<<(std::ostream& os, const TreeFragment& x) {
+  x.DebugRec(x.nodes.size() - 1, &os);
+  return os;
+}
+
+}
+
+#endif