#!/usr/bin/env perl
  
  # This program takes the output of count_rules.pl, which is tuples
  # of the form
  #
  # rule;destress;right-count;partial-count;wrong-count
  #
  # and outputs lines of the form
  #
  # rule;de-stress;score
  #
  # where the score, between 0 and 1 (1 better), is 
  # equal to:
  #
  # It forms a score between 0 and 1, of the form:
  # ((#correct) +  $partial_score * (#partial)) / (#correct + #partial + #wrong + $ballast)
  #
  # where $partial_score (e.g. 0.8) is the score we assign to a "partial" match,
  # and $ballast is a small number, e.g. 1, that is treated like "extra" wrong scores, to penalize
  # rules with few observations.
  #
  # It outputs all rules that at are at least the
  
  $ballast = 1;
  $partial_score = 0.8;
  $destress_penalty = 1.0e-05; # Give destressed rules a small
  # penalty vs. their no-destress counterparts, so if we
  # have to choose arbitrarily we won't destress (seems safer)>
  
  for ($n = 1; $n <= 4; $n++) {
    if ($ARGV[0] eq "--ballast") {
      shift @ARGV;
      $ballast = shift @ARGV;
    }
    if ($ARGV[0] eq "--partial-score") {
      shift @ARGV;
      $partial_score = shift @ARGV;
      ($partial_score >= 0.0 && $partial_score <= 1.0) || die "Invalid partial_score: $partial_score";
    }
  }
  
  (@ARGV == 0 || @ARGV == 1) || die "Usage: score_rules.pl [--ballast ballast-count] [--partial-score partial-score] [input from count_rules.pl]";
  
  while(<>) {
    @A = split(";", $_);
    @A == 5 || die "Bad input line; $_";
    ($rule,$destress,$right_count,$partial_count,$wrong_count) = @A;
    $rule_score = ($right_count + $partial_score*$partial_count) / 
      ($right_count+$partial_count+$wrong_count+$ballast);
    if ($destress eq "yes") { $rule_score -= $destress_penalty; }
    print join(";", $rule, $destress, sprintf("%.5f", $rule_score)) . "
  ";
  }