package TAP::Parser::Iterator;

use strict;
use vars qw($VERSION @ISA);

use TAP::Object ();

@ISA = qw(TAP::Object);

=head1 NAME

TAP::Parser::Iterator - Base class for TAP source iterators

=head1 VERSION

Version 3.26

=cut

$VERSION = '3.26';

=head1 SYNOPSIS

# to subclass:
use vars qw(@ISA);
use TAP::Parser::Iterator ();
@ISA = qw(TAP::Parser::Iterator);
sub _initialize {
# see TAP::Object...
}

sub next_raw { ... }
sub wait { ... }
sub exit { ... }

=head1 DESCRIPTION

This is a simple iterator base class that defines L<TAP::Parser>'s iterator
API. Iterators are typically created from L<TAP::Parser::SourceHandler>s.

=head1 METHODS

=head2 Class Methods

=head3 C<new>

Create an iterator. Provided by L<TAP::Object>.

=head2 Instance Methods

=head3 C<next>

while ( my $item = $iter->next ) { ... }

Iterate through it, of course.

=head3 C<next_raw>

B<Note:> this method is abstract and should be overridden.

while ( my $item = $iter->next_raw ) { ... }

Iterate raw input without applying any fixes for quirky input syntax.

=cut

sub next {
my $self = shift;
my $line = $self->next_raw;

# vms nit: When encountering 'not ok', vms often has the 'not' on a line
# by itself:
# not
# ok 1 - 'I hate VMS'
if ( defined($line) and $line =~ /^\s*not\s*$/ ) {
$line .= ( $self->next_raw || '' );
}

return $line;
}

sub next_raw {
require Carp;
my $msg = Carp::longmess('abstract method called directly!');
$_[0]->_croak($msg);
}

=head3 C<handle_unicode>

If necessary switch the input stream to handle unicode. This only has
any effect for I/O handle based streams.

The default implementation does nothing.

=cut

sub handle_unicode { }

=head3 C<get_select_handles>

Return a list of filehandles that may be used upstream in a select()
call to signal that this Iterator is ready. Iterators that are not
handle-based should return an empty list.

The default implementation does nothing.

=cut

sub get_select_handles {
return;
}

=head3 C<wait>

B<Note:> this method is abstract and should be overridden.

my $wait_status = $iter->wait;

Return the C<wait> status for this iterator.

=head3 C<exit>

B<Note:> this method is abstract and should be overridden.

my $wait_status = $iter->exit;

Return the C<exit> status for this iterator.

=cut

sub wait {
require Carp;
my $msg = Carp::longmess('abstract method called directly!');
$_[0]->_croak($msg);
}

sub exit {
require Carp;
my $msg = Carp::longmess('abstract method called directly!');
$_[0]->_croak($msg);
}

1;

=head1 SUBCLASSING

Please see L<TAP::Parser/SUBCLASSING> for a subclassing overview.

You must override the abstract methods as noted above.

=head2 Example

L<TAP::Parser::Iterator::Array> is probably the easiest example to follow.
There's not much point repeating it here.

=head1 SEE ALSO

L<TAP::Object>,
L<TAP::Parser>,
L<TAP::Parser::Iterator::Array>,
L<TAP::Parser::Iterator::Stream>,
L<TAP::Parser::Iterator::Process>,

=cut