=head1 NAME
pdl2 - Simple shell (version 2) for PDL
=head1 SYNOPSIS
Use PDL interactively:
%> pdl2
pdl> $x = sequence(10) # or any other perl or PDL command
pdl> print "\$x = $x\n";
$x = [0 1 2 3 4 5 6 7 8 9]
=head1 DESCRIPTION
The C<pdl2> program, also known as the Perldl2 shell, is a second
generation version of the original C<perldl> interactive PDL shell.
It attempts to be backward compatible in usage while providing
improved features, better support for Perl syntax, and an more
easily extended framework based on the L<Devel::REPL> shell.
If you have L<Devel::REPL> version 1.003011 or later, then C<pdl2>
will start with full functionality. If L<Devel::REPL> is not
installed or found then C<pdl2> will print a warning and run
the legacy C<perldl> shell command instead.
By default, command lines beginning with the default prompt
of either C<pdl2> or C<perldl> (one of 'pdl> ', 'PDL> ', or
'perldl> ') will have the prefix string and surrounding
whitespace stripped. This allows for easy cut-and-paste
from sample PDL shell sessions or other examples into another
PDL shell session.
=head1 FUNCTIONS
=head2 do_print
=for ref
Toggle print-by-default on and off (default value: off)
By default, C<pdl2> does not print the results of operations
since the results can be very large (e.g., a small 640x480
RGBA image is still more than 1_000_000 elements). However,
for experimenting and debugging more complex structures,
it helps to see the results of I<every> operation. The
C<do_print> routine allows you to toggle between the default
"quiet" operation and a full Read, Evaluate, Loop style.
=for example
pdl> $x = pdl(3,2)
pdl> do_print
1
pdl> $x = pdl(3,2)
$PDL1 = [3 2];
pdl> do_print
pdl> $x = pdl(3,2)
=head1 VARIABLES
=over 4
=item $PDL::toolongtoprint
The maximal size pdls to print (defaults to 10000 elements).
This is not just a C<perldl> or C<pdl2> variable but it is
something that is usually needed in an interactive debugging
session.
=back
=head1 SEE ALSO
L<perldl>, L<Devel::REPL>