Add search library to cdec (not used yet)

1 files changed, 69 insertions, 0 deletions

diff --git a/klm/search/weights.cc b/klm/search/weights.cc
new file mode 100644
index 00000000..82ff3f12
--- /dev/null
+++ b/klm/search/weights.cc
@@ -0,0 +1,69 @@
+#include "search/weights.hh"
+#include "util/tokenize_piece.hh"
+
+#include <cstdlib>
+
+namespace search {
+
+namespace {
+struct Insert {
+  void operator()(boost::unordered_map<std::string, search::Score> &map, StringPiece name, search::Score score) const {
+    std::string copy(name.data(), name.size());
+    map[copy] = score;
+  }
+};
+
+struct DotProduct {
+  search::Score total;
+  DotProduct() : total(0.0) {}
+
+  void operator()(const boost::unordered_map<std::string, search::Score> &map, StringPiece name, search::Score score) {
+    boost::unordered_map<std::string, search::Score>::const_iterator i(FindStringPiece(map, name));
+    if (i != map.end()) 
+      total += score * i->second;
+  }
+};
+
+template <class Map, class Op> void Parse(StringPiece text, Map &map, Op &op) {
+  for (util::TokenIter<util::SingleCharacter, true> spaces(text, ' '); spaces; ++spaces) {
+    util::TokenIter<util::SingleCharacter> equals(*spaces, '=');
+    UTIL_THROW_IF(!equals, WeightParseException, "Bad weight token " << *spaces);
+    StringPiece name(*equals);
+    UTIL_THROW_IF(!++equals, WeightParseException, "Bad weight token " << *spaces);
+    char *end;
+    // Assumes proper termination.  
+    double value = std::strtod(equals->data(), &end);
+    UTIL_THROW_IF(end != equals->data() + equals->size(), WeightParseException, "Failed to parse weight" << *equals);
+    UTIL_THROW_IF(++equals, WeightParseException, "Too many equals in " << *spaces);
+    op(map, name, value);
+  }
+}
+
+} // namespace
+
+Weights::Weights(StringPiece text) {
+  Insert op;
+  Parse<Map, Insert>(text, map_, op);
+  lm_ = Steal("LanguageModel");
+  oov_ = Steal("OOV");
+  word_penalty_ = Steal("WordPenalty");
+}
+
+search::Score Weights::DotNoLM(StringPiece text) const {
+  DotProduct dot;
+  Parse<const Map, DotProduct>(text, map_, dot);
+  return dot.total;
+}
+
+float Weights::Steal(const std::string &str) {
+  Map::iterator i(map_.find(str));
+  if (i == map_.end()) {
+    return 0.0;
+  } else {
+    float ret = i->second;
+    map_.erase(i);
+    return ret;
+  }
+}
+
+} // namespace search