From 13d3dd3a8dca40c3ce70c2b117964ca3bfa5f971 Mon Sep 17 00:00:00 2001
From: Chris Dyer <cdyer@allegro.clab.cs.cmu.edu>
Date: Sat, 25 Oct 2014 00:18:38 -0400
Subject: extract features from converted conll files

---
 decoder/ff_conll.cc | 250 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 250 insertions(+)
 create mode 100644 decoder/ff_conll.cc

(limited to 'decoder/ff_conll.cc')

diff --git a/decoder/ff_conll.cc b/decoder/ff_conll.cc
new file mode 100644
index 00000000..8ded44b7
--- /dev/null
+++ b/decoder/ff_conll.cc
@@ -0,0 +1,250 @@
+#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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