File: //usr/local/share/perl5/XML/SAX/PurePerl/Exception.pm
# $Id$
package XML::SAX::PurePerl::Exception;
use strict;
use overload '""' => "stringify";
use vars qw/$StackTrace/;
$StackTrace = $ENV{XML_DEBUG} || 0;
sub throw {
    my $class = shift;
    die $class->new(@_);
}
sub new {
    my $class = shift;
    my %opts = @_;
    die "Invalid options" unless exists $opts{Message};
    
    if ($opts{reader}) {
        return bless { Message => $opts{Message},
                        Exception => undef, # not sure what this is for!!!
                        ColumnNumber => $opts{reader}->column,
                        LineNumber => $opts{reader}->line,
                        PublicId => $opts{reader}->public_id,
                        SystemId => $opts{reader}->system_id,
                        $StackTrace ? (StackTrace => stacktrace()) : (),
                    }, $class;
    }
    return bless { Message => $opts{Message},
                    Exception => undef, # not sure what this is for!!!
                  }, $class;
}
sub stringify {
    my $self = shift;
    local $^W;
    return $self->{Message} . " [Ln: " . $self->{LineNumber} . 
                ", Col: " . $self->{ColumnNumber} . "]" .
                ($StackTrace ? stackstring($self->{StackTrace}) : "") . "\n";
}
sub stacktrace {
    my $i = 2;
    my @fulltrace;
    while (my @trace = caller($i++)) {
        my %hash;
        @hash{qw(Package Filename Line)} = @trace[0..2];
        push @fulltrace, \%hash;
    }
    return \@fulltrace;
}
sub stackstring {
    my $stacktrace = shift;
    my $string = "\nFrom:\n";
    foreach my $current (@$stacktrace) {
        $string .= $current->{Filename} . " Line: " . $current->{Line} . "\n";
    }
    return $string;
}
1;