a bit more documentation

lib/Throwable.pm

@@ -1,14 +1,50 @@
 package Throwable;
 use Moose::Role;
+# ABSTRACT: a role for classes that can be thrown
+
+=head1 SYNOPSIS
+
+  package Redirect;
+  use Moose;
+  with 'Throwable';
+
+  has url => (is => 'ro');
+
+...then later...
+
+  Redirect->throw({ url => $url });
+
+=head1 DESCRIPTION
+
+Throwable is a role for classes that are meant to be thrown as exceptions to
+standard program flow.  It is very simple and does only two things: saves any
+previous value for C<$@> and calls C<die $self>.
+
+=attr previous_exception
+
+This attribute is created automatically, and stores the value of C<$@> when the
+Throwable object is created.
+
+=cut
 
 has 'previous_exception' => (
-  is      => 'ro',
-  default => sub {
+  is       => 'ro',
+  init_arg => undef,
+  default  => sub {
     return unless defined $@ and ref $@ or length $@;
     return $@;
   },
 );
 
+=method throw
+
+  Something::Throwable->throw({ attr => $value });
+
+This method will call new, passing all arguments along to new, and will then
+use the created object as the only argument to C<die>.
+
+=cut
+
 sub throw {
   my ($self, @rest) = @_;
   my $throwable = $self->new(@rest);

lib/Throwable/Error.pm

@@ -1,6 +1,7 @@
 package Throwable::Error;
 use Moose;
 with 'Throwable';
+# ABSTRACT: an easy-to-use class for error objects
 
 use overload
   q{""}    => 'as_string',