The Perl Toolchain Summit needs more sponsors. If your company depends on Perl, please support this very important event.
package Hints_pod_examples;
use strict;
use warnings;

use base qw(Exporter);

our %DOES = ( 'autodie::hints::provider' => 1 );

our @EXPORT_OK = qw(
	undef_scalar false_scalar zero_scalar empty_list default_list
	empty_or_false_list undef_n_error_list foo re_fail bar
	think_positive my_system bizarro_system	
);

use autodie::hints;

sub AUTODIE_HINTS {
    return {
        # Scalar failures always return undef:
        undef_scalar =>    {  fail => undef  },

        # Scalar failures return any false value [default behaviour]:
        false_scalar =>    {  fail => sub { return ! $_[0] }  },

        # Scalar failures always return zero explicitly:
        zero_scalar =>     {  fail => '0'  },

        # List failures always return empty list:
        # We never want these called in a scalar context
        empty_list  =>     {  scalar => sub { 1 }, list => []  },

        # List failures return C<()> or C<(undef)> [default expectation]:
        default_list => {  fail => sub { ! @_ || @_ == 1 && !defined $_[0] }  },

        # List failures return C<()> or a single false value:
        empty_or_false_list => {  fail => sub { ! @_ || @_ == 1 && !$_[0] }  },

        # List failures return (undef, "some string")
        undef_n_error_list => {  fail => sub { @_ == 2 && !defined $_[0] }  },
    };
}	

# Define some subs that all just return their arguments
sub undef_scalar { return wantarray ? @_ : $_[0] }
sub false_scalar { return wantarray ? @_ : $_[0] }
sub zero_scalar  { return wantarray ? @_ : $_[0] }
sub empty_list   { return wantarray ? @_ : $_[0] }
sub default_list { return wantarray ? @_ : $_[0] }
sub empty_or_false_list { return wantarray ? @_ : $_[0] }
sub undef_n_error_list { return wantarray ? @_  : $_[0] }


# Unsuccessful foo() returns 0 in all contexts...
autodie::hints->set_hints_for(
    \&foo,
    {
	scalar => 0,
	list   => [0],
    }
);

sub foo { return wantarray ? @_ : $_[0] }

# Unsuccessful re_fail() returns 'FAIL' or '_FAIL' in scalar context,
#                    returns (-1) in list context...
autodie::hints->set_hints_for(
    \&re_fail,
    {
	scalar => qr/^ _? FAIL $/xms,
	list   => [-1],
    }
);

sub re_fail { return wantarray ? @_ : $_[0] }

# Unsuccessful bar() returns 0 in all contexts...
autodie::hints->set_hints_for(
    \&bar,
    {
	scalar => 0,
	list   => [0],
    }
);

sub bar { return wantarray ? @_ : $_[0] }

# Unsuccessful think_positive() returns negative number on failure...
autodie::hints->set_hints_for(
    \&think_positive,
    {
	scalar => sub { $_[0] < 0 },
	list   => sub { $_[0] < 0 },
    }
);

sub think_positive { return wantarray ? @_ : $_[0] }

# Unsuccessful my_system() returns non-zero on failure...
autodie::hints->set_hints_for(
    \&my_system,
    {
	scalar => sub { $_[0] != 0 },
	list   => sub { $_[0] != 0 },
    }
);
sub my_system { return wantarray ? @_ : $_[0] };

1;