eval "$gen\n1" or die $@;
}
+sub args_min {
+ my $self = shift;
+ my $r = 0;
+ $r++ if defined $self->invocant;
+ $r += $self->positional_required;
+ $r += $self->named_required * 2;
+ $r
+}
+
+sub args_max {
+ my $self = shift;
+ return 0 + 'Inf' if defined $self->slurpy || $self->named_required || $self->named_optional;
+ my $r = 0;
+ $r++ if defined $self->invocant;
+ $r += $self->positional_required;
+ $r += $self->positional_optional;
+ $r
+}
+
'ok'
__END__
+
+=encoding UTF-8
+
+=head1 NAME
+
+Function::Parameters::Info - Information about parameter lists
+
+=head1 SYNOPSIS
+
+ use Function::Parameters;
+
+ fun foo($x, $y, :$hello, :$world = undef) {}
+
+ my $info = Function::Parameters::info \&foo;
+ my $p0 = $info->invocant; # undef
+ my @p1 = $info->positional_required; # ('$x', '$y')
+ my @p2 = $info->positional_optional; # ()
+ my @p3 = $info->named_required; # ('$hello')
+ my @p4 = $info->named_optional; # ('$world')
+ my $p5 = $info->slurpy; # undef
+ my $min = $info->args_min; # 4
+ my $max = $info->args_max; # inf
+
+ my $invocant = Function::Parameters::info(method () { 42 })->invocant; # '$self'
+
+ my $slurpy = Function::Parameters::info(fun {})->slurpy; # '@_'
+
+=head1 DESCRIPTION
+
+L<C<Function::Parameters::info>|Function::Parameters/Introspection> returns
+objects of this class to describe parameter lists of functions. The following
+methods are available:
+
+=head2 C<< $info->invocant >>
+
+Returns the name of the variable into which the first argument is
+L<C<shift>|perlfunc/shift>ed into automatically, or C<undef> if no such thing
+exists. This will usually return C<'$self'> for methods.
+
+=head2 C<< $info->positional_required >>
+
+Returns a list of the names of the required positional parameters (or a count
+in scalar context).
+
+=head2 C<< $info->positional_optional >>
+
+Returns a list of the names of the optional positional parameters (or a count
+in scalar context).
+
+=head2 C<< $info->named_required >>
+
+Returns a list of the names of the required named parameters (or a count
+in scalar context).
+
+=head2 C<< $info->named_optional >>
+
+Returns a list of the names of the optional named parameters (or a count
+in scalar context).
+
+=head2 C<< $info->slurpy >>
+
+Returns the name of the final array or hash that gobbles up all remaining
+arguments, or C<undef> if no such thing exists.
+
+As a special case, functions defined without an explicit parameter list (i.e.
+without C<( )>) will return C<'@_'> here because they accept any number of
+arguments.
+
+=head2 C<< $info->args_min >>
+
+Returns the minimum number of arguments this function requires. This is
+computed as follows: Invocant and required positional parameters count 1 each.
+Optional parameters don't count. Required named parameters count 2 each (key +
+value). Slurpy parameters don't count either because they accept empty lists.
+
+=head2 C<< $info->args_max >>
+
+Returns the maximum number of arguments this function accepts. This is computed
+as follows: If there is any named or slurpy parameter, the result is C<Inf>.
+Otherwise the result is the sum of all invocant and positional parameters.
+
+=head1 SEE ALSO
+
+L<Function::Parameters>
+
+=head1 AUTHOR
+
+Lukas Mai, C<< <l.mai at web.de> >>
+
+=head1 COPYRIGHT & LICENSE
+
+Copyright 2012 Lukas Mai.
+
+This program is free software; you can redistribute it and/or modify it
+under the terms of either: the GNU General Public License as published
+by the Free Software Foundation; or the Artistic License.
+
+See http://dev.perl.org/licenses/ for more information.
+
+=cut