[ID 19991022.005] qw and x operator

This is a bug report for perl from marcel.grunauer@lovely.net,
generated with the help of perlbug 1.26 running under perl 5.00502.

I've come across a behavior of the qw() operator in conjunction with
the x operator that I can't explain. I've checked perlop.


#!/usr/bin/perl -w
use strict;
my %test;
@test{qw/a b c/} = ('n') x 3;
print "$_ => $test{$_}\n" foreach keys %test;


produces, as expected:

a => n
b => n
c => n


If I replace the hash slice line above with

@test{qw/a b c/} = qw/n/ x 3;

it produces:

Bareword "x" not allowed while "strict subs" in use at ...
Unquoted string "x" may clash with future reserved word at ... 
syntax error at ..., near "qw/n/ x "
Number found where operator expected at ..., near "x 3"
	(Do you need to predeclare x?)

The following two work ok:

@test{qw/a b c/} = (qw/n/) x 3;
@test{qw/a b c/} = (split(' ', q/n/)) x 3;


According to Tad McClellan (tadmc@metronet.com):

> Note also that you get the same messages if you replace the
> line above with just:
> 
> x 3;
> 
> Looks like perl is taking "@test{qw/a b c/} = qw/n/" as an
> entire statement, and then resuming the parse...


According to Abigail (abigail@delanet.com):

> Based on [the repetition operator documentation], I would assume that
> 
>     @test{qw/a b c/} = qw/n/ x 3;
> 
> would lead to:
> 
>     %test = (a => '111', b => undef, c => undef);

> This is because the left operand of x will be evaluated in scalar context,
> hence the split qw// does is done to @_, and the amount of produced fields
> is returned. This being 1, leads to 1 x 3 which is '111'.

---
Site configuration information for perl 5.00502:

Summary of my perl5 (5.0 patchlevel 5 subversion 02) configuration:
  Platform:
    osname=MSWin32, osvers=4.0, archname=MSWin32-x86-object
    uname=''
    hint=recommended, useposix=true, d_sigaction=undef
    usethreads=undef useperlio=undef d_sfio=undef
  Compiler:
    cc='cl.exe', optimize='-O2 -MD -DNDEBUG -TP -GX', gccversion=
    cppflags='-DWIN32'
    ccflags ='-O2 -MD -DNDEBUG -TP -GX -DWIN32 -D_CONSOLE -DNO_STRICT
-DHAVE_DES_FCRYPT -DPERL_OBJECT'
    stdchar='char', d_stdstdio=define, usevfork=false
    intsize=4, longsize=4, ptrsize=4, doublesize=8
    d_longlong=undef, longlongsize=8, d_longdbl=define, longdblsize=10
    alignbytes=8, usemymalloc=n, prototype=define
  Linker and Libraries:
    ld='link', ldflags ='-nologo -nodefaultlib -release -machine:x86'
    libpth="C:\usr\lib\core" "C:\Program Files\Mts\Lib" 
    libs= oldnames.lib kernel32.lib user32.lib gdi32.lib  winspool.lib
comdlg32.lib advapi32.lib shell32.lib ole32.lib  oleaut32.lib
netapi32.lib uuid.lib wsock32.lib mpr.lib winmm.lib  version.lib
odbc32.lib odbccp32.lib PerlCRT.lib
    libc=C:\usr\lib\core\PerlCRT.lib, so=dll, useshrplib=yes,
libperl=perlcore.lib
  Dynamic Linking:
    dlsrc=dl_win32.xs, dlext=dll, d_dlsymun=undef, ccdlflags=' '
    cccdlflags=' ', lddlflags='-dll -nologo -nodefaultlib -release
-machine:x86'

Locally applied patches:
    ACTIVEPERL_LOCAL_PATCHES_ENTRY

---
@INC for perl 5.00502:
    C:\root\perldev\lib
    C:\usr\lib
    C:\usr\site\lib
    .

---
Environment for perl 5.00502:
    HOME=C:\root
    LANG (unset)
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)

PATH=c:\cygnus\CYGWIN~1\H-I586~1\bin;.;C:\usr\bin;C:\WINNT\system32;C:\WINNT;C:\rootbin;c:\cygnus\CYGWIN~1\H-I586~1\bin;G:\jdk1.2.2\bin;c:\Program
Files\Winzip;C:\DAYNA
    PERL5LIB=C:\root\perldev\lib
    PERL_BADLANG (unset)
    SHELL=/bin/sh

-- 
Marcel, Perl Padawan
sub AUTOLOAD{$_=$AUTOLOAD;s;.*::;;;y;_; ;;print}&Just_Another_Perl_Hacker;

Message from the perl bug squashing team at 'perlbug@perl.org'

• Smoke 18779 linux 2.4.18-bf2.4 /home/abigail/Src/perl-5.9.0 by abigail
• [ID 19991022.005] qw and x operator by Marcel Grunauer