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authorChris Dyer <redpony@gmail.com>2014-04-25 13:20:06 -0400
committerChris Dyer <redpony@gmail.com>2014-04-25 13:20:06 -0400
commit18a1d98f5bd60ea195a6c3aaf8feb740da752f7e (patch)
tree80a66eebb4db916f68309bfc21ab52ea7b6fb131 /decoder
parent4078d043bb3d3ebc386af44f6e1af3036f0afc25 (diff)
fix tree-to-string forest so it works with cube pruning assumptions
Diffstat (limited to 'decoder')
-rw-r--r--decoder/tree2string_translator.cc17
1 files changed, 16 insertions, 1 deletions
diff --git a/decoder/tree2string_translator.cc b/decoder/tree2string_translator.cc
index 29caaf8f..c353f7ca 100644
--- a/decoder/tree2string_translator.cc
+++ b/decoder/tree2string_translator.cc
@@ -126,6 +126,17 @@ namespace std {
};
};
+void AddDummyGoalNode(Hypergraph* hg) {
+ static const int kGOAL = -TD::Convert("Goal");
+ static TRulePtr kGOAL_RULE(new TRule("[Goal] ||| [X] ||| [1]"));
+ unsigned old_goal_node_idx = hg->nodes_.size() - 1;
+ HG::Node* goal_node = hg->AddNode(kGOAL);
+ goal_node->node_hash = 1;
+ TailNodeVector tail(1, old_goal_node_idx);
+ HG::Edge* new_edge = hg->AddEdge(kGOAL_RULE, tail);
+ hg->ConnectEdgeToHeadNode(new_edge, goal_node);
+}
+
struct Tree2StringTranslatorImpl {
vector<boost::shared_ptr<Tree2StringGrammarNode>> root;
bool add_pass_through_rules;
@@ -308,14 +319,18 @@ struct Tree2StringTranslatorImpl {
if (goal_it == x2hg.end()) return false;
//cerr << "Goal node: " << goal << endl;
hg.TopologicallySortNodesAndEdges(goal_it->second);
- hg.Reweight(weights);
// there might be nodes that cannot be derived
// the following takes care of them
vector<bool> prune(hg.edges_.size(), false);
hg.PruneEdges(prune, true);
if (hg.edges_.size() == 0) return false;
+ // rescoring assumes the goal edge is arity 1 (code laziness), add that here
+ AddDummyGoalNode(&hg);
+
+ hg.Reweight(weights);
//hg.PrintGraphviz();
+
minus_lm_forest->swap(hg);
return true;
}