package Function::Parameters::Info;
use v5.14.0;
-
use warnings;
-use Moo;
+our $VERSION = '0.04';
+
+# If Moo isn't loaded yet but Moose is, avoid pulling in Moo and fall back to Moose
+my $Moo;
+BEGIN {
+ if ($INC{'Moose.pm'} && !$INC{'Moo.pm'}) {
+ $Moo = 'Moose';
+ } else {
+ require Moo;
+ $Moo = 'Moo';
+ }
+ $Moo->import;
+}
+
+{
+ package Function::Parameters::Param;
+
+ BEGIN { $Moo->import; }
+ use overload
+ fallback => 1,
+ '""' => sub { $_[0]->name },
+ ;
+
+ has $_ => (is => 'ro') for qw(name type);
-our $VERSION = '0.01';
+ __PACKAGE__->meta->make_immutable;
+}
my @pn_ro = glob '{positional,named}_{required,optional}';
eval "$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;
+ $r
+}
+
+__PACKAGE__->meta->make_immutable;
+
'ok'
__END__
+
+=encoding UTF-8
+
+=head1 NAME
+
+Function::Parameters::Info - Information about parameter lists
+
+=head1 SYNOPSIS
+
+ use Function::Parameters;
+
+ fun foo($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 $info->invocant
+
+Returns the name of the variable into which the first argument is
+L<C<shift>|perlfunc/shift>ed automatically, or C<undef> if no such thing
+exists. This will usually return C<'$self'> for methods.
+
+=head2 $info->positional_required
+
+Returns a list of the names of the required positional parameters (or a count
+in scalar context).
+
+=head2 $info->positional_optional
+
+Returns a list of the names of the optional positional parameters (or a count
+in scalar context).
+
+=head2 $info->named_required
+
+Returns a list of the names of the required named parameters (or a count
+in scalar context).
+
+=head2 $info->named_optional
+
+Returns a list of the names of the optional named parameters (or a count
+in scalar context).
+
+=head2 $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 $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 $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.
+
+=head2 Experimental feature: Types
+
+All the methods described above actually return parameter objects wherever the
+description says "name". These objects have two methods: C<name>, which
+returns the name of the parameter (as a plain string), and C<type>, which
+returns the corresponding type constraint object (or undef if there was no type
+specified).
+
+This should be invisible if you don't use types because the objects also
+L<overload|overload> stringification to call C<name>. That is, if you treat
+parameter objects like strings, they behave like strings (i.e. their names).
+
+=head1 SEE ALSO
+
+L<Function::Parameters>
+
+=head1 AUTHOR
+
+Lukas Mai, C<< <l.mai at web.de> >>
+
+=head1 COPYRIGHT & LICENSE
+
+Copyright 2013 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
projects / p5sagit/Function-Parameters.git / blobdiff