Problem with exception handler in guide?

[Matthew Pressly <mp...@claborn.net>]

I am trying to get the exception class described in the guide to work, but am having trouble with "die" returning the class incorrectly.

The example in the guide was:
  die My::Exception->RetCode(code => 204);

The module code is at:
http://thingy.kcilink.com/modperlguide/perl/The_My_Exception_class_in_its_e.html
with two modifications (the last "die" in sub AUTOLOAD was changed to CORE::die to prevent a perl warning message about it being ambiguous, and the missing semicolon at the end of the first line "package ..." was added).

The following script code does not work
#-------------------------------------
use My::Exception;
eval {
        die My::Exception->Return(code => "abc");
};
if ($@) {
        use Data::Dumper;
        print Dumper($@);
}
#-------------------------------------

It generates the output:
#-------------------------------------
$VAR1 = bless( {
                 'text' => 'My::Exception',
                 'caller' => {
                               'line' => 19,
                               'filename' => 'My/Exception.pm',
                               'package' => 'My::Exception'
                             }
               }, 'My::Exception::UnCaught' );
#-------------------------------------
with the class indicating that the exception was not caught.  Tracing it in the debugger shows that it executes My::Exception::die using "My::Exception" as the first argument.

If I put parens around the argument to die, as follows, it works (calls AUTOLOAD first then returns result of that as first argument to My::Exception::die), returning the correctly classed object.
Code:
#-------------------------------------
use My::Exception;
eval {
        die (My::Exception->Return(code => "abc"));
};
if ($@) {
        use Data::Dumper;
        print Dumper($@);
}
#-------------------------------------

Output:
#-------------------------------------
$VAR1 = bless( {
                 'caller' => {
                               'line' => 5,
                               'filename' => './exceptions2',
                               'package' => 'main'
                             },
                 'code' => 'abc'
               }, 'My::Exception::Return' );
#-------------------------------------


It appears that "->" is too low a precedence.  Is there a way around this without requiring that parentheses be used around die's arguments? I'm running this under perl5.6.0.  Here is output of perl -V:

Summary of my perl5 (revision 5.0 version 6 subversion 0) configuration:
  Platform:
    osname=linux, osvers=2.4.0, archname=i586-linux
    uname='linux manson 2.4.0 #1 wed aug 2 20:22:26 gmt 2000 i686 unknown '
    config_args='-ds -e -Dprefix=/usr -Di_db -Di_dbm -Di_ndbm -Di_gdbm'
    hint=recommended, useposix=true, d_sigaction=define
    usethreads=undef use5005threads=undef useithreads=undef usemultiplicity=undef
    useperlio=undef d_sfio=undef uselargefiles=define 
    use64bitint=undef use64bitall=undef uselongdouble=undef usesocks=undef
  Compiler:
    cc='cc', optimize='-O2 -pipe', gccversion=2.95.2 19991024 (release)
    cppflags='-fno-strict-aliasing -I/usr/local/include'
    ccflags ='-fno-strict-aliasing -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64'
    stdchar='char', d_stdstdio=define, usevfork=false
    intsize=4, longsize=4, ptrsize=4, doublesize=8
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=12
    ivtype='long', ivsize=4, nvtype='double', nvsize=8, Off_t='off_t', lseeksize=8
    alignbytes=4, usemymalloc=n, prototype=define
  Linker and Libraries:
    ld='cc', ldflags =' -L/usr/local/lib'
    libpth=/usr/local/lib /lib /usr/lib
    libs=-lnsl -ldl -lm -lc -lcrypt
    libc=, so=so, useshrplib=false, libperl=libperl.a
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-rdynamic'
    cccdlflags='-fpic', lddlflags='-shared -L/usr/local/lib'


Characteristics of this binary (from libperl): 
  Compile-time options: USE_LARGE_FILES
  Built under linux
  Compiled at Jan 19 2001 05:42:10
  %ENV:
    PERL5LIB="/home/mpressly/development/library"
  @INC:
    /home/mpressly/development/library
    /usr/lib/perl5/5.6.0/i586-linux
    /usr/lib/perl5/5.6.0
    /usr/lib/perl5/site_perl/5.6.0/i586-linux
    /usr/lib/perl5/site_perl/5.6.0
    /usr/lib/perl5/site_perl
    .


Matthew Pressly

Re: Problem with exception handler in guide?

["Aaron E. Ross" <ro...@coreference.com>]

>         die (My::Exception->Return(code => "abc"));

    $ perl -I/tmp -MMy::Exception -e 'die "My::Exception"->RetCode( code => 204 )'
    $ My::Exception::RetCode=HASH(0x8185570)

 not much better, but no parens. :) 

 i don't really understand the precedence problem though.

 Aaron