package Sam::Constants;

use strict;
use warnings;

use constant {
    ABC_1 => 1, ABC_2 => 2, ABC_3 => 3,
    DEF_1 => 4, DEF_2 => 5, DEF_3 => 6,
    GHI_1 => 7, GHI_2 => 8, GHI_3 => 9,
};

BEGIN {
    use Exporter 'import';
    my @abc = qw{ABC_1 ABC_2 ABC_3};
    my @def = qw{DEF_1 DEF_2 DEF_3};
    my @ghi = qw{GHI_1 GHI_2 GHI_3};
    my @abcdef = (@abc, @def);
    my @all = (@abc, @def, @ghi);
    our @EXPORT_OK = @all;
    our %EXPORT_TAGS = (
        abc => [@abc],
        def => [@def],
        ghi => [@ghi],
        abcdef => [@abcdef],
        all => [@all],
    );
}

1;

##</code><code>##

$ alias perl_sam_const
alias perl_sam_const='perl -I/home/ken/tmp/pm_11139384/lib -Mstrict -Mwarnings -E'

##</code><code>##

# import a single constant
$ perl_sam_const 'use Sam::Constants qw{ABC_2}; say ABC_2'
2

# check that other ABC_* constants are not imported
$ perl_sam_const 'use Sam::Constants qw{ABC_2}; say for ABC_1, ABC_2, ABC_3'
Bareword "ABC_1" not allowed while "strict subs" in use at -e line 1.
Bareword "ABC_3" not allowed while "strict subs" in use at -e line 1.
Execution of -e aborted due to compilation errors.

# import all ABC_* constants
$ perl_sam_const 'use Sam::Constants qw{:abc}; say for ABC_1, ABC_2, ABC_3'
1
2
3

# import all ABC_* and GHI_* constants (using two tags)
$ perl_sam_const 'use Sam::Constants qw{:abc :ghi}; say for ABC_1, GHI_2'
1
8

# import all ABC_* and DEF_* constants (using just one tag)
$ perl_sam_const 'use Sam::Constants qw{:abcdef}; say for DEF_3, ABC_3'
6
3

# import all constants
$ perl_sam_const 'use Sam::Constants qw{:all}; say for ABC_1, DEF_2, GHI_3'
1
5
9