[ID 20010330.003] O=Deparse,-p does not preserve "operationalsemantics"

This is a bug report for perl from rmb1@cise.npl.co.uk,
generated with the help of perlbug 1.26 running under perl 5.00503.


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[Please enter your report here]

I presumed that the output of perl -MO=Deparse should be the same
(have the same semantics as) the input; at least to the extent 
that the two perl fragments produced the same output.

e.g. 
% perl -MO=Deparse orig.pl > deparse.pl
Then
% perl orig.pl
% perl deparse.pl
give the same output.

I also expected that the output of O=Deparse,-p would also give
the same output.  But ...  

% cat orig.pl
my $xyz = (1,2); print $xyz,"\n"

% perl orig.pl
2

% perl -MO=Deparse orig.pl > deparse.pl
orig.pl syntax OK

% cat deparse.pl
my $xyz = ('???', 2);
print $xyz, "\n";

% perl deparse.pl
2

% perl -MO=Deparse,-p orig.pl > deparse-p.pl
orig.pl syntax OK

% cat deparse-p.pl
(my($xyz) = ('???', 2));
print($xyz, "\n");

% perl deparse-p.pl
???


The problem is that the extra brackets round $xyz in C<my($xyz)>
are not just syntax, they change the sematics by giving list 
context to the assignment.
I had a look at B::Deparse.pm but I can't see how to fix this.

Robin

[Please do not change anything below this line]
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Site configuration information for perl 5.00503:

Configured by root at Sat Sep 11 15:08:44 BST 1999.

Summary of my perl5 (5.0 patchlevel 5 subversion 3) configuration:
  Platform:
    osname=solaris, osvers=2.6, archname=sun4-solaris
    uname='sunos capulin 5.6 generic_105181-10 sun4m sparc sunw,sparcstation-20 '
    hint=recommended, useposix=true, d_sigaction=define
    usethreads=undef useperlio=undef d_sfio=undef
  Compiler:
    cc='gcc -B/usr/ccs/bin/', optimize='-O', gccversion=2.95.1 19990816 (release)
    cppflags='-I/usr/local/include'
    ccflags ='-I/usr/local/include'
    stdchar='unsigned char', d_stdstdio=define, usevfork=false
    intsize=4, longsize=4, ptrsize=4, doublesize=8
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=16
    alignbytes=8, usemymalloc=y, prototype=define
  Linker and Libraries:
    ld='gcc -B/usr/ccs/bin/', ldflags =' -L/usr/local/lib'
    libpth=/usr/local/lib /lib /usr/lib /usr/ccs/lib
    libs=-lsocket -lnsl -ldl -lm -lc -lcrypt
    libc=/lib/libc.so, so=so, useshrplib=false, libperl=libperl.a
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags=' '
    cccdlflags='-fPIC', lddlflags='-G -L/usr/local/lib'

Locally applied patches:
    

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@INC for perl 5.00503:
    /home/rmb1/appl/lib/perl5/site_perl
    /home/rmb1/appl/lib/perl5/site_perl/5.005/sun4-solaris
    /home/rmb1/appl/lib/perl5/site_perl/5.005
    /usr/local/lib/perl5/5.00503/sun4-solaris
    /usr/local/lib/perl5/5.00503
    /usr/local/lib/perl5/site_perl/5.005/sun4-solaris
    /usr/local/lib/perl5/site_perl/5.005
    .

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Environment for perl 5.00503:
    HOME=/home/rmb1
    LANG=C
    LANGUAGE (unset)
    LD_LIBRARY_PATH=/usr/lib
    LOGDIR (unset)
    PATH=/home/rmb1/appl/script:/opt/SUNWspci/bin/:/usr/tempest/bin:/usr/local/bin:/usr/local/Admigration/exec:/usr/local/hotjava/bin:/usr/openwin/bin:/usr/dt/bin:/usr/ccs/bin:/usr/bin
    PERL5LIB=/home/rmb1/appl/lib/perl5/site_perl:/home/rmb1/appl/lib/perl5/site_perl/5.005
    PERL_BADLANG (unset)
    SHELL=/bin/csh

• [ID 20010330.003] O=Deparse,-p does not preserve "operationalsemantics" by Robin Barker
• Re: [ID 20010330.003] O=Deparse,-p does not preserve "operational semantics" by Robin Houston