#!/usr/bin/env perl
  # Copyright 2010-2012 Microsoft Corporation  Johns Hopkins University (Author: Daniel Povey)
  # Apache 2.0.
  
  undef $field_begin;
  undef $field_end;
  
  
  if ($ARGV[0] eq "-f") {
    shift @ARGV; 
    $field_spec = shift @ARGV; 
    if ($field_spec =~ m/^\d+$/) {
      $field_begin = $field_spec - 1; $field_end = $field_spec - 1;
    }
    if ($field_spec =~ m/^(\d*)[-:](\d*)/) { # accept e.g. 1:10 as a courtesty (properly, 1-10)
      if ($1 ne "") {
        $field_begin = $1 - 1; # Change to zero-based indexing.
      }
      if ($2 ne "") {
        $field_end = $2 - 1; # Change to zero-based indexing.
      }
    }
    if (!defined $field_begin && !defined $field_end) {
      die "Bad argument to -f option: $field_spec"; 
    }
  }
  $symtab = shift @ARGV;
  if(!defined $symtab) {
      print STDERR "Usage: sym2int.pl [options] symtab [input] > output
  " .
        "options: [-f (<field>|<field_start>-<field-end>)]
  " .
        "e.g.: -f 2, or -f 3-4
  ";
      exit(1);
  }
  
  open(F, "<$symtab") || die "Error opening symbol table file $symtab";
  while(<F>) {
      @A = split(" ", $_);
      @A == 2 || die "bad line in symbol table file: $_";
      $int2sym{$A[1]} = $A[0];
  }
  
  sub int2sym {
      my $a = shift @_;
      my $pos = shift @_;
      if($a !~  m:^\d+$:) { # not all digits..
        $pos1 = $pos+1; # make it one-based.
        die "int2sym.pl: found noninteger token $a [in position $pos1]
  ";
      }
      $s = $int2sym{$a};
      if(!defined ($s)) {
        die "int2sym.pl: integer $a not in symbol table $symtab.";
      }
      return $s;
  }
  
  $error = 0;
  while (<>) {
    @A = split(" ", $_);
    for ($pos = 0; $pos <= $#A; $pos++) {
      $a = $A[$pos];
      if ( (!defined $field_begin || $pos >= $field_begin)
           && (!defined $field_end || $pos <= $field_end)) {
        $a = int2sym($a, $pos);
      }
      print $a . " ";
    }
    print "
  ";
  }