add max-unknowns arg to ConstrainedDecoding FF

1 files changed, 7 insertions, 1 deletions

diff --git a/moses/Phrase.cpp b/moses/Phrase.cpp
index ae0572357..14f764115 100644
--- a/moses/Phrase.cpp
+++ b/moses/Phrase.cpp
@@ -373,11 +373,12 @@ void Phrase::InitStartEndWord()
   AddWord(endWord);
 }
 
-size_t Phrase::Find(const Phrase &sought) const
+size_t Phrase::Find(const Phrase &sought, int maxUnknown) const
 {
 	size_t maxStartPos = GetSize() - sought.GetSize();
 	for (size_t startThisPos = 0; startThisPos <= maxStartPos; ++startThisPos) {
 		size_t thisPos = startThisPos;
+		int currUnknowns = 0;
 		size_t soughtPos;
 		for (soughtPos = 0; soughtPos < sought.GetSize(); ++soughtPos) {
 			const Word &soughtWord = sought.GetWord(soughtPos);
@@ -386,6 +387,11 @@ size_t Phrase::Find(const Phrase &sought) const
 			if (soughtWord == thisWord) {
 				++thisPos;
 			}
+			else if (soughtWord.IsOOV() && (maxUnknown < 0 || currUnknowns < maxUnknown)) {
+				// the output has an OOV word. Allow a certain number of OOVs
+				++currUnknowns;
+				++thisPos;
+			}
 			else {
 				break;
 			}