package RecordParser::FixedWidth;

# constructor takes the name of the source file
sub new {
    my ( $class, $source ) = @_;

##</code><code>##

    my $template;
    my @fields;
    my @column_specs = lookup_specs($source);
    for my $column_spec ( @column_specs ) {
        my ($field, $offset, $width) 
            = @$column_spec{qw(field offset width)};
        $template .= "\@${offset}A$width";
        push @fields, $field;
    }
    open my $reader, '<', $source;       

##</code><code>##

    my $obj = {
        IO         => $reader,
        template   => $template,
        fields_ref => \@fields,
    };
    bless $obj => $class;
}

##</code><code>##

sub next {
    my ( $self ) = @_;
    my ($reader, $template, $fields_ref) 
        = @$self{qw(IO template fields_ref)};
    my @fields = @$fields_ref;

    my $record = <$reader>;
    return unless defined $record;

##</code><code>##

    my %value_of;
    my @values = unpack($template, $record);
    @value_of{@fields} = @values;

##</code><code>##

    return \%value_of;
}