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-rw-r--r--decoder/ff_conll.cc250
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diff --git a/decoder/ff_conll.cc b/decoder/ff_conll.cc
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+#include "ff_conll.h"
+
+#include <stdlib.h>
+#include <sstream>
+#include <cassert>
+#include <cmath>
+#include <boost/lexical_cast.hpp>
+
+#include "hg.h"
+#include "filelib.h"
+#include "stringlib.h"
+#include "sentence_metadata.h"
+#include "lattice.h"
+#include "fdict.h"
+#include "verbose.h"
+#include "tdict.h"
+
+CoNLLFeatures::CoNLLFeatures(const string& param) {
+ // cerr << "initializing CoNLLFeatures with parameters: " << param;
+ kSOS = TD::Convert("<s>");
+ kEOS = TD::Convert("</s>");
+ macro_regex = sregex::compile("%([xy])\\[(-[1-9][0-9]*|0|[1-9][1-9]*)]");
+ ParseArgs(param);
+}
+
+string CoNLLFeatures::Escape(const string& x) const {
+ string y = x;
+ for (int i = 0; i < y.size(); ++i) {
+ if (y[i] == '=') y[i]='_';
+ if (y[i] == ';') y[i]='_';
+ }
+ return y;
+}
+
+// replace %x[relative_location] or %y[relative_location] with actual_token
+// within feature_instance
+void CoNLLFeatures::ReplaceMacroWithString(
+ string& feature_instance, bool token_vs_label, int relative_location,
+ const string& actual_token) const {
+
+ stringstream macro;
+ if (token_vs_label) {
+ macro << "%x[";
+ } else {
+ macro << "%y[";
+ }
+ macro << relative_location << "]";
+ int macro_index = feature_instance.find(macro.str());
+ if (macro_index == string::npos) {
+ cerr << "Can't find macro " << macro.str() << " in feature template "
+ << feature_instance;
+ abort();
+ }
+ feature_instance.replace(macro_index, macro.str().size(), actual_token);
+}
+
+void CoNLLFeatures::ReplaceTokenMacroWithString(
+ string& feature_instance, int relative_location,
+ const string& actual_token) const {
+
+ ReplaceMacroWithString(feature_instance, true, relative_location,
+ actual_token);
+}
+
+void CoNLLFeatures::ReplaceLabelMacroWithString(
+ string& feature_instance, int relative_location,
+ const string& actual_token) const {
+
+ ReplaceMacroWithString(feature_instance, false, relative_location,
+ actual_token);
+}
+
+void CoNLLFeatures::Error(const string& error_message) const {
+ cerr << "Error: " << error_message << "\n\n"
+
+ << "CoNLLFeatures Usage: \n"
+ << " feature_function=CoNLLFeatures -t <TEMPLATE>\n\n"
+
+ << "Example <TEMPLATE>: U1:%x[-1]_%x[0]|%y[0]\n\n"
+
+ << "%x[k] and %y[k] are macros to be instantiated with an input\n"
+ << "token (for x) or a label (for y). k specifies the relative\n"
+ << "location of the input token or label with respect to the current\n"
+ << "position. For x, k is an integer value. For y, k must be 0 (to\n"
+ << "be extended).\n\n";
+
+ abort();
+}
+
+void CoNLLFeatures::ParseArgs(const string& in) {
+ which_feat = 0;
+ vector<string> const& argv = SplitOnWhitespace(in);
+ for (vector<string>::const_iterator i = argv.begin(); i != argv.end(); ++i) {
+ string const& s = *i;
+ if (s[0] == '-') {
+ if (s.size() > 2) {
+ stringstream msg;
+ msg << s << " is an invalid option for CoNLLFeatures.";
+ Error(msg.str());
+ }
+
+ switch (s[1]) {
+
+ case 'w': {
+ if (++i == argv.end()) {
+ Error("Missing parameter to -w");
+ }
+ which_feat = boost::lexical_cast<unsigned>(*i);
+ break;
+ }
+ // feature template
+ case 't': {
+ if (++i == argv.end()) {
+ Error("Can't find template.");
+ }
+ feature_template = *i;
+ string::const_iterator start = feature_template.begin();
+ string::const_iterator end = feature_template.end();
+ smatch macro_match;
+
+ // parse the template
+ while (regex_search(start, end, macro_match, macro_regex)) {
+ // get the relative location
+ string relative_location_str(macro_match[2].first,
+ macro_match[2].second);
+ int relative_location = atoi(relative_location_str.c_str());
+ // add it to the list of relative locations for token or label
+ // (i.e. x or y)
+ bool valid_location = true;
+ if (*macro_match[1].first == 'x') {
+ // add it to token locations
+ token_relative_locations.push_back(relative_location);
+ } else {
+ if (relative_location != 0) { valid_location = false; }
+ // add it to label locations
+ label_relative_locations.push_back(relative_location);
+ }
+ if (!valid_location) {
+ stringstream msg;
+ msg << "Relative location " << relative_location
+ << " in feature template " << feature_template
+ << " is invalid.";
+ Error(msg.str());
+ }
+ start = macro_match[0].second;
+ }
+ break;
+ }
+
+ // TODO: arguments to specify kSOS and kEOS
+
+ default: {
+ stringstream msg;
+ msg << "Invalid option on CoNLLFeatures: " << s;
+ Error(msg.str());
+ break;
+ }
+ } // end of switch
+ } // end of if (token starts with hyphen)
+ } // end of for loop (over arguments)
+
+ // the -t (i.e. template) option is mandatory in this feature function
+ if (label_relative_locations.size() == 0 ||
+ token_relative_locations.size() == 0) {
+ stringstream msg;
+ msg << "Feature template must specify at least one"
+ << "token macro (e.g. x[-1]) and one label macro (e.g. y[0]).";
+ Error(msg.str());
+ }
+}
+
+void CoNLLFeatures::PrepareForInput(const SentenceMetadata& smeta) {
+ const Lattice& sl = smeta.GetSourceLattice();
+ current_input.resize(sl.size());
+ for (unsigned i = 0; i < sl.size(); ++i) {
+ if (sl[i].size() != 1) {
+ stringstream msg;
+ msg << "CoNLLFeatures don't support lattice inputs!\nid="
+ << smeta.GetSentenceId() << endl;
+ Error(msg.str());
+ }
+ current_input[i] = sl[i][0].label;
+ }
+ vector<WordID> wids;
+ string fn = "feat";
+ fn += boost::lexical_cast<string>(which_feat);
+ string feats = smeta.GetSGMLValue(fn);
+ if (feats.size() == 0) {
+ Error("Can't find " + fn + " in <seg>\n");
+ }
+ TD::ConvertSentence(feats, &wids);
+ assert(current_input.size() == wids.size());
+ current_input = wids;
+}
+
+void CoNLLFeatures::TraversalFeaturesImpl(
+ const SentenceMetadata& smeta, const Hypergraph::Edge& edge,
+ const vector<const void*>& ant_contexts, SparseVector<double>* features,
+ SparseVector<double>* estimated_features, void* context) const {
+
+ const TRule& rule = *edge.rule_;
+ // arity = 0, no nonterminals
+ // size = 1, predicted label is a single token
+ if (rule.Arity() != 0 ||
+ rule.e_.size() != 1) {
+ return;
+ }
+
+ // replace label macros with actual label strings
+ // NOTE: currently, this feature function doesn't allow any label
+ // macros except %y[0]. but you can look at as much of the source as you want
+ const WordID y0 = rule.e_[0];
+ string y0_str = TD::Convert(y0);
+
+ // start of the span in the input being labeled
+ const int from_src_index = edge.i_;
+ // end of the span in the input
+ const int to_src_index = edge.j_;
+
+ // in the case of tagging the size of the spans being labeled will
+ // always be 1, but in other formalisms, you can have bigger spans
+ if (to_src_index - from_src_index != 1) {
+ cerr << "CoNLLFeatures doesn't support input spans of length != 1";
+ abort();
+ }
+
+ string feature_instance = feature_template;
+ // replace token macros with actual token strings
+ for (unsigned i = 0; i < token_relative_locations.size(); ++i) {
+ int loc = token_relative_locations[i];
+ WordID x = loc < 0? kSOS: kEOS;
+ if(from_src_index + loc >= 0 &&
+ from_src_index + loc < current_input.size()) {
+ x = current_input[from_src_index + loc];
+ }
+ string x_str = TD::Convert(x);
+ ReplaceTokenMacroWithString(feature_instance, loc, x_str);
+ }
+
+ ReplaceLabelMacroWithString(feature_instance, 0, y0_str);
+
+ // pick a real value for this feature
+ double fval = 1.0;
+
+ // add it to the feature vector
+ // FD::Convert converts the feature string to a feature int
+ // Escape makes sure the feature string doesn't have any bad
+ // symbols that could confuse a parser somewhere
+ features->add_value(FD::Convert(Escape(feature_instance)), fval);
+}
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