package B::Bblock;
+
+our $VERSION = '1.00';
+
use Exporter ();
@ISA = "Exporter";
@EXPORT_OK = qw(find_leaders);
=head1 SYNOPSIS
- perl -MO=Bblock[,OPTIONS] foo.pl
+ # External interface
+ perl -MO=Bblock[,OPTIONS] foo.pl
+
+ # Programmatic API
+ use B::Bblock qw(find_leaders);
+ my $leaders = find_leaders($root_op, $start_op);
=head1 DESCRIPTION
A basic block is a series of operations which is known to execute from
start to finish, with no possiblity of branching or halting.
+It can be used either stand alone or from inside another program.
+
+=for _private
+Somebody who understands the stand-alone options document them, please.
+
+=head2 Functions
+
+=over 4
+
+=item B<find_leaders>
+
+ my $leaders = find_leaders($root_op, $start_op);
+
+Given the root of the op tree and an op from which to start
+processing, it will return a hash ref representing all the ops which
+start a block.
+
+=for _private
+The above description may be somewhat wrong.
+
+The values of %$leaders are the op objects themselves. Keys are $$op
+addresses.
+
+=for _private
+Above cribbed from B::CC's comments. What's a $$op address?
+
+=back
+
+
=head1 AUTHOR
Malcolm Beattie, C<mbeattie@sable.ox.ac.uk>