=head1 NAME

kurila116delta - what is new for Perl Kurila 1.16

=head1 DESCRIPTION

This document describes differences between Perl Kurila 1.15 and Perl Kurila 1.16

=head1 Highlights In Perl Kurila 1.16

Structured assignments. 

=head1 Core Enhancements

=head2 Structured assignments

Structured assignments are a new way, to extract values from complex
structures.

For example:

    %( aap => $aap, ?noot => $noot ) = $h;

C<$h> must be an hash with a key C<aap> and possible a key C<noot>, the
corresponding values are assigned to C<$aap> and C<$noot>.  Assigns
C<$aap> to the key C<$noot>.

As a more basic example:

    @( $a, $b ) = @list;

Assigns C<$a> to the first element, and C<$b> the second element. If there
are more elements in the list an error is raised. To allow for more
element do

    @($a, $b, ...) = @list;

To allow assignment without two elements ad a C<?> in front of the
variable:

    @($a, ? $b, ...) = @list;

If C<@list> only has only element C<$b> will be set to C<undef>.
Similairly for hashes:

    %( aap => $aap, ?noot => $noot, ... ) = $h;

C<$h> must be a hash which must have the key C<aap>. C<$aap> is
assigned the value of C<$h{aap}>, and C<$noot> is assigned the
value of C<$h{?noot}>. 
Extra values in a hash or array can be ignored using C<...> or
assigned to hash or array using C<< @< >> or C<< %< >>. For example:

    @($a, @< $remaining) = @list

Assigns the first element of C<@list> to C<$a> and the remaining elements to
C<$remaining>.

    @( $a, %< $h ) = @( "arg1", "key1" => "value1" );

After the assignment C<$a> is C<"arg1"> and C<$h> is C<< %( "key1" => "value1" ) >>

=head3 Rationale

Improve assignments.

=head2 Controlled hash and array element access and creation

Default when you access a hash key or array element which does not
exists an error is raised. To automaticly create the hash key or array
element if it does not exists, add the C<+> operator to the key,
i.e. C<$h{+$key}>. To ignore accessing a non-existent key or element,
add the C<?> to the key, i.e. C<@a[?$i]>.

=head3 Rationale

Direct control over the creation and access of hash and array
elements.

=head2 Removed list assigments

List assignments are no longer possible

=head3 Rationale

List assignments have been removed in favour of structured assigments.

=head1 KNOWN BUGS

=head2 Documentation

Documentation has not been updated for many of the changes for kurila.

=head2 Self referential assignment problems

Assigning some value to a part of itself behaves unexpected.

=head2 Tied hashes with complex data

Tied hashes do not work correctly with complex data
structures. Assigning arrays or hashes to a value of tied hash might
behave strange.

=head2 Limited platform support

Perl Kurila has only been tested/build for x86_64-linux-gnu-thread-multi platform.

=head1 SEE ALSO

The F<INSTALL> file for how to build Perl Kurila.

The F<README> file for general stuff.

The F<Artistic> and F<Copying> files for copyright information.

=head1 HISTORY

Written by Gerard Goossen <F<gerard@tty.nl>>.

=cut