package String;

use strict;
use warnings;

sub new {

  my $class = shift;
  my %arg = @_;
  
  my $ddl = { a => { start  => 0,
                     length => 5,
                   },
              b => { start  => 5,
                     length => 5,
                   },
              n => { start  => 10,
                     length => 1,
                   },
            };

  my $self  = { ddl  => $ddl,
                line => undef,
              };

  bless $self, $class;
}

sub line : lvalue {

  my $self = shift;
  my $line = shift;

  $self->{'line'};
}

sub field_start {

  my $self  = shift;
  my $field = shift;

  return $self->{'ddl'}{$field}{'start'};
}

sub field_length {

  my $self  = shift;
  my $field = shift;

  return $self->{'ddl'}{$field}{'length'};
}

sub field_int : lvalue {

  my $self  = shift;
  my $field = shift;

  print "SUBSTR: ", substr($self->{'line'}, $self->field_start($field), $self->field_length($field)), "\n";

  substr($self->{'line'}, $self->field_start($field), $self->field_length($field) );
}

1;