mongo.pl

my $map = <<MAP;
function() {                                                                                                    
  if( this.comment != null && this.date > $date ){                                                              
     try{                                                                                                       
       this.comment.match(/(@[a-zA-Z0-9_]+)/);                                                                  
       emit(RegExp.\$1, 1);                                                                                     
     }catch(e){                                                                                                 
     }                                                                                                          
  }                                                                                                             
}                                                                                                               
MAP                                                                                                             
    my $reduce = <<REDUCE;
function(k,vals) {                                                                                              
    var sum = 0;                                                                                                
    for( var i in vals) sum += vals[i];                                                                         
    return sum;                                                                                                 
}                                                                                                               
REDUCE                                                                                                          
my $cmd = Tie::IxHash->new(
    "mapreduce" => "post",
    "map"       => $map,
    "reduce"    => $reduce,
    "query" => 'type.sale',
);

my $res = $db->run_command($cmd);
my $col = $res->{result};

my @rows =
  $db->$col->query( {}, { limit => 100, sort_by => { value => -1 } } )->all();
$db->$col->drop();