lt-proc: Implement option to output n-best paths.

Using the same option names as `hfst-proc` we add options in
lt-proc to output n-best paths using the weight values.

Closes apertium#3

lttoolbox/att_compiler.cc

@@ -149,7 +149,7 @@ AttCompiler::parse(string const &file_name, wstring const &dir)
     }
     split(line, L'\t', tokens);
 
-    from = convert(tokens[0]);
+    from = static_cast<int>(convert(tokens[0]));
 
     AttNode* source = get_node(from);
     /* First line: the initial state is of both types. */
@@ -174,7 +174,7 @@ AttCompiler::parse(string const &file_name, wstring const &dir)
     } 
     else
     {
-      to = convert(tokens[1]);
+      to = static_cast<int>(convert(tokens[1]));
       if(dir == L"RL")
       {
         upper = tokens[3];
@@ -266,8 +266,8 @@ AttCompiler::extract_transducer(TransducerType type)
  */
 void 
 AttCompiler::_extract_transducer(TransducerType type, int from,
-                         Transducer& transducer, map<int, int>& corr,
-                         set<int>& visited, double& cost)
+                                 Transducer& transducer, map<int, int>& corr,
+                                 set<int>& visited, double& cost)
 {
   if (visited.find(from) != visited.end())
   {
@@ -287,7 +287,7 @@ AttCompiler::_extract_transducer(TransducerType type, int from,
   for (vector<Transduction>::const_iterator it = source->transductions.begin();
        it != source->transductions.end(); ++it) 
   {
-    if ((it->type & type) != type) 
+    if ((it->type & type) != type)
     {
       continue;  // Not the right type
     }
@@ -310,7 +310,7 @@ AttCompiler::_extract_transducer(TransducerType type, int from,
       to_t = corr[it->to];
       transducer.linkStates(from_t, to_t, it->tag, it->weight);
     }
-    else 
+    else
     {
       /* We haven't seen it yet: add a new state! */
       to_t = transducer.insertNewSingleTransduction(it->tag, from_t, it->weight);
@@ -336,7 +336,7 @@ AttCompiler::_extract_transducer(TransducerType type, int from,
  */
 void
 AttCompiler::classify(int from, map<int, TransducerType>& visited, bool path,
-              TransducerType type)
+                      TransducerType type)
 {
   AttNode* source = get_node(from);
   if (visited.find(from) != visited.end())
@@ -368,7 +368,7 @@ AttCompiler::classify(int from, map<int, TransducerType>& visited, bool path,
       if (upper_word)  next_type |= WORD;
       if (upper_punct) next_type |= PUNCT;
       next_path = true;
-    } 
+    }
     else
     {
       /* Otherwise (not yet, already): target's type is the same as ours. */

lttoolbox/att_compiler.h

@@ -55,9 +55,9 @@ namespace
   }
 
   /** Converts a string to a number. Slow, but at this point I don't care. */
-  int convert(const wstring& s) 
+  double convert(const wstring& s)
   {
-    int ret;
+    double ret;
     wistringstream ss(s);
     ss >> ret;
     return ret;
@@ -134,9 +134,7 @@ class AttCompiler
    */
   int starting_state;
   /**
-   * Value of the final weight after a complete valid transduction. We assume it
-   * is the default value of weight for an entry if not specified otherwise or
-   * for the case of unweighted automata/transducers.
+   * Default value of weight of a transduction unless specified.
    */
   double default_weight;
 

lttoolbox/compression.cc

@@ -307,7 +307,7 @@ Compression::long_multibyte_write(const double& value, FILE *output)
 {
   int exp = 0;
 
-  long unsigned int mantissa = static_cast<long unsigned int>(std::numeric_limits<long int>::max() * frexp(value, &exp));
+  long unsigned int mantissa = static_cast<long unsigned int>(0x40000000 * frexp(value, &exp));
   unsigned int exponent = static_cast<unsigned int>(exp);
 
   multibyte_write(mantissa, output);
@@ -319,7 +319,7 @@ Compression::long_multibyte_write(const double& value, ostream &output)
 {
   int exp = 0;
 
-  long unsigned int mantissa = static_cast<long unsigned int>(std::numeric_limits<long int>::max() * frexp(value, &exp));
+  long unsigned int mantissa = static_cast<long unsigned int>(0x40000000 * frexp(value, &exp));
   unsigned int exponent = static_cast<unsigned int>(exp);
 
   multibyte_write(mantissa, output);
@@ -335,7 +335,7 @@ Compression::long_multibyte_read(FILE *input)
   long unsigned int mantissa = multibyte_read(input);
   int exponent = multibyte_read(input);
 
-  double value = static_cast<double>(static_cast<long int>(mantissa)) / std::numeric_limits<long int>::max();
+  double value = static_cast<double>(static_cast<long int>(mantissa)) / 0x40000000;
   result = ldexp(value, exponent);
 
   return result;
@@ -349,7 +349,7 @@ Compression::long_multibyte_read(istream &input)
   long unsigned int mantissa = multibyte_read(input);
   int exponent = multibyte_read(input);
 
-  double value = static_cast<double>(static_cast<long int>(mantissa)) / std::numeric_limits<long int>::max();
+  double value = static_cast<double>(static_cast<long int>(mantissa)) / 0x40000000;
   result = ldexp(value, exponent);
 
   return result;