package DEBUGGER;

use Exporter;
@ISA = qw(Exporter);

$::debug_level = 0; # default debug level

sub _check_debug_level {
    my ($debug_level_low, $debug_level_hi) = @_;
    $debug_level_hi ||= $::debug_level;

    return (($::debug_level >= $debug_level_low)
            && ($::debug_level <= $debug_level_hi));
}

# --- break($;$) ----
# set break point.
#
sub break($;$) {
    $DB::single = _check_debug_level(@_);
}
push @EXPORT, 'break';
#
# // break()
# -------------------

# --- break_if($;$$) ----
# set conditional break point.
# (could also be tied to specific
#  debugging levels)
#
sub break_if($;$$) {
  $DB::single = shift
    && (@_ && _check_debug_level(@_));
}
push @EXPORT, 'break_if';
#
# // break()
# -------------------

sub import {
  my ($pkg, %args) = @_;
  $::debug_level = $args{debug_level} if (exists $args{debug_level});

  __PACKAGE__->export_to_level(1);
}

##</code><code>##

use strict;
use DEBUGGER (
              debug_level => 2,
              );

my $x = 2 * 2;

# will break here if debug level falls between
# 1 and 3 (inclusively).
break 1,3;
my $s = "foobar";

break 5;
print "will break here iff debug level is 5\n";

# break here if $x is less than 3
# and debug_level is set to 2
break_if $x < 5, 2;
print "exiting...\n";