use Carp ();
use Any::Moose;
-use Any::Moose 'Util' => [ qw[find_meta does_role] ];
+use Any::Moose 'Util' => [ qw<find_meta does_role> ];
use Any::Moose 'Util::TypeConstraints';
=head1 ATTRIBUTES
=head2 C<< insert into => \@list, overwrite => $overwrite, replace => $replace >>
Inserts the current rule into the list of rules C<@list>.
+The list is expected to be ordered, in that each rule must come after all the rules that have a target that inherits or consumes the original rule's own target.
-If C<$replace> is false, then the rule will be appended to the C<@list> ; except if there already is an existent entry for the same target, in which case it will be overwritten if C<$overwrite> is true, or an exception will be thrown if it is false.
+If C<$replace> is false, then the rule will be inserted into C<@list> after all the rules applying to the target's subclasses/subroles and before all its superclasses/superroles ; except if there is already an existent entry for the same target, in which case it will be overwritten if C<$overwrite> is true, or an exception will be thrown if it is false.
If C<$replace> is true, then the rule will replace the first rule in the list that is a subclass or that consumes the role denoted by the target.
All the subsequent rules in the list that inherit or consume the target will be removed.
+Returns true if and only if an existent rule was replaced.
+
=cut
sub insert {
my $overwrite = $args{overwrite};
my $replace = $args{replace};
- my $target = $rule->target;
- my $is_role = $rule->is_role;
-
if ($replace) {
my (@remove, $replaced);
return 1 if $replaced;
} else { # Replace only an existent rule
+ my $target = $rule->target;
+
+ my $last_descendant = undef;
+ my $first_ancestor = undef;
for my $i (0 .. $#$list) {
- my $old_target = $list->[$i]->target;
+ my $old_rule = $list->[$i];
+ my $old_target = $old_rule->target;
if ($old_target eq $target) {
Carp::confess("Default rule already defined for target $target")
unless $overwrite;
splice @$list, $i, 1, $rule;
return 1;
+ } elsif ($rule->handles($old_target)) {
+ $last_descendant = $i;
+ } elsif ($old_rule->handles($target)) {
+ $first_ancestor = $i;
}
}
+
+ my $pos;
+ if (defined $first_ancestor) {
+ Carp::confess("Unsorted rule list")
+ if defined $last_descendant and $first_ancestor <= $last_descendant;
+ $pos = $first_ancestor;
+ } elsif (defined $last_descendant) {
+ $pos = $last_descendant + 1;
+ }
+
+ if (defined $pos) {
+ splice @$list, $pos, 1, $rule;
+ return 0;
+ }
}
push @$list, $rule;