=head1 VERSION
-Version 0.01
+Version 0.02
=cut
-our $VERSION = '0.01';
+our $VERSION = '0.02';
=head1 DESCRIPTION
-A functor takes a L<LaTeX::TikZ::Set> tree and clones it according to certain rules.
-Rules can apply not only to L<LaTeX::TikZ::Set> objects, but also to the L<LaTeX::TikZ::Mod> objects they contain.
+A functor takes a L<LaTeX::TikZ::Set> tree and returns a new, transmuted version of it according to certain rules.
+It recursively visits all the nodes of the tree, building a new set out of the result of the functor on the child sets.
+
+Rules are stored as L<LaTeX::TikZ::Functor::Rule> objects.
+They can apply not only to L<LaTeX::TikZ::Set> consumer objects, but also to the L<LaTeX::TikZ::Mod> consumer objects they contain.
+When the functor is called against a set object and that the returned set is different from the original (as told by C<==>, which defaults to object identity), then the functor is also applied to all the mods of the set, and their transformed counterparts are added to the new set.
+
+When the functor is called onto a set or mod object, all its associated rules are tried successively, and the handler of the first matching rule is executed with :
+
+=over 4
+
+=item *
+
+the functor object as its first argument ;
+
+=item *
+
+the current set or mod object as its second argument ;
+
+=item *
+
+the arguments passed to the functor itself starting at the third argument.
+
+=back
+
+The handler is expected to return the new set or mod that will replace the old one in the resulting set tree.
+
+If no matching rule is found, the object is returned as-is.
=cut
=head2 C<< new rules => [ $spec1 => $handler1, $spec2 => $handler2, ... ] >>
-Creates a new functor object that will use both the default and these user-specified rules.
+Creates a new functor object that will use both the default and the user-specified rules.
The functor is also a code reference that expects to be called against L<LaTeX::TikZ::Set> objects.
The default set and mod rules clone their relevant objects, so you get a clone functor (for the default set types) if you don't specify any user rule.
my $clone = Tikz->functor;
my $dup = $set->$clone;
-If there is already a default rule for one of the C<$spec>s, it is replaced by the new one ; otherwise, the user rule is appended to the list of default rules.
+If there is already a default rule for one of the C<$spec>s, it is replaced by the new one ; otherwise, the user rule is inserted into the list of default rules after all its descendants' rules and before all its ancestors' rules.
# A translator
my $translate = Tikz->functor(
}
}
}
- my $new_set = $rule ? $rule->handler->($self, $set, @_)
- : $set;
- my $is_new = $new_set ne $set;
+ return $set unless $rule;
+
+ my $new_set = $rule->handler->($self, $set, @_);
+ return $set if $new_set == $set;
my @new_mods;
MOD:
push @new_mods, $rule ? $rule->handler->($self, $mod, @_)
: $mod;
}
-
- $new_set->mod(@new_mods) if $is_new;
+ $new_set->mod(@new_mods);
return $new_set;
}, $class;
Adds to all subsequently created functors a default rule for the class or role C<$spec>.
-An exception is thrown if there is already a default rule for C<$spec> ; otherwise, the new rule is appended to the current list of rules.
+An exception is thrown if there is already a default rule for C<$spec> ; otherwise, the new rule is inserted into the current list of default rules after all its descendants' rules and before all its ancestors' rules.
But if C<$spec> begins with C<'+'>, the rule will replace I<all> default rules that apply to subclasses or subroles of C<$spec> (including C<$spec> itself).
Returns true if and only if an existent rule was replaced.
=head1 SEE ALSO
-L<LaTeX::TikZ>.
+L<LaTeX::TikZ>, L<LaTeX::TikZ::Functor::Rule>.
=head1 AUTHOR