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scalar operator does not change void context #2011

Closed p5pRT closed 20 years ago

p5pRT commented 23 years ago

Migrated from rt.perl.org#3286 (status was 'resolved')

Searchable as RT3286$

p5pRT commented 23 years ago

From @ysth

Created by @ysth

The scalar operator does not change void context.

[D​:\home\sthoenna]perl #!perl -wl sub context { print wantarray ? 'list' : defined wantarray ? 'scalar' : 'void'} my @​x = scalar context; # works my $x = scalar context; # works scalar context; # doesn't work __END__ scalar scalar void

Perl Info ``` Flags: category=core severity=medium Site configuration information for perl v5.6.0: Configured by sthoenna at Thu Mar 23 16:36:26 PST 2000. Summary of my perl5 (revision 5.0 version 6 subversion 0) configuration: Platform: osname=os2, osvers=2.30, archname=os2 uname='os2 efn.org 2 2.30 i386 ' config_args='-de -Dprefix=d:/perl -Aoptimize=-DDEBUGGING' 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='gcc', optimize='-O2 -fomit-frame-pointer -malign-loops=2 -malign-jumps=2 -malign-functions=2 -s -DDEBUGGING', gccversion=2.8.1 cppflags='-Zomf -Zmt -DDOSISH -DOS2=2 -DEMBED -I. -D_EMX_CRT_REV_=62' ccflags ='-Zomf -Zmt -DDOSISH -DOS2=2 -DEMBED -I. -D_EMX_CRT_REV_=62' 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=4 alignbytes=4, usemymalloc=y, prototype=define Linker and Libraries: ld='gcc', ldflags ='-Zexe -Zomf -Zmt -Zcrtdll -Zstack 32000' libpth=d:/emx/lib d:/emx/lib/mt libs=-lsocket -lm -lbsd libc=d:/emx/lib/mt/c_import.lib, so=dll, useshrplib=true, libperl=libperl.lib Dynamic Linking: dlsrc=dl_dlopen.xs, dlext=dll, d_dlsymun=undef, ccdlflags=' ' cccdlflags='-Zdll', lddlflags='-Zdll -Zomf -Zmt -Zcrtdll -s' Locally applied patches: @INC for perl v5.6.0: d:/perl/lib/5.6.0/os2 d:/perl/lib/5.6.0 d:/perl/lib/site_perl/5.6.0/os2 d:/perl/lib/site_perl/5.6.0 d:/perl/lib/site_perl . Environment for perl v5.6.0: HOME=d:\home\sthoenna LANG=en_us LANGUAGE (unset) LD_LIBRARY_PATH (unset) LOGDIR (unset) PATH=d:\bin;C:\OS2;d:\perl\bin;C:\OS2\SYSTEM;C:\OS2\INSTALL;C:\;C:\OS2\MDOS;C:\OS2\APPS;C:\MMOS2;d:\os2apps\util;d:\DOSAPPS\UTIL;c:\sio;D:\WINDOWS;d:\pdksh;d:\emx\bin;d:\emacs\19.33\bin;d:\ispell PERL_BADLANG (unset) PERL_SH_DIR=d:\BIN SHELL (unset) ```
p5pRT commented 23 years ago

From @ysth

Created by @ysth

The scalar operator does not change void context.

[D​:\home\sthoenna]perl #!perl -wl sub context { print wantarray ? 'list' : defined wantarray ? 'scalar' : 'void'} my @​x = scalar context; # works my $x = scalar context; # works scalar context; # doesn't work __END__ scalar scalar void

Perl Info ``` Flags: category=core severity=medium Site configuration information for perl v5.6.0: Configured by sthoenna at Thu Mar 23 16:36:26 PST 2000. Summary of my perl5 (revision 5.0 version 6 subversion 0) configuration: Platform: osname=os2, osvers=2.30, archname=os2 uname='os2 efn.org 2 2.30 i386 ' config_args='-de -Dprefix=d:/perl -Aoptimize=-DDEBUGGING' 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='gcc', optimize='-O2 -fomit-frame-pointer -malign-loops=2 -malign-jumps=2 -malign-functions=2 -s -DDEBUGGING', gccversion=2.8.1 cppflags='-Zomf -Zmt -DDOSISH -DOS2=2 -DEMBED -I. -D_EMX_CRT_REV_=62' ccflags ='-Zomf -Zmt -DDOSISH -DOS2=2 -DEMBED -I. -D_EMX_CRT_REV_=62' 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=4 alignbytes=4, usemymalloc=y, prototype=define Linker and Libraries: ld='gcc', ldflags ='-Zexe -Zomf -Zmt -Zcrtdll -Zstack 32000' libpth=d:/emx/lib d:/emx/lib/mt libs=-lsocket -lm -lbsd libc=d:/emx/lib/mt/c_import.lib, so=dll, useshrplib=true, libperl=libperl.lib Dynamic Linking: dlsrc=dl_dlopen.xs, dlext=dll, d_dlsymun=undef, ccdlflags=' ' cccdlflags='-Zdll', lddlflags='-Zdll -Zomf -Zmt -Zcrtdll -s' Locally applied patches: @INC for perl v5.6.0: d:/perl/lib/5.6.0/os2 d:/perl/lib/5.6.0 d:/perl/lib/site_perl/5.6.0/os2 d:/perl/lib/site_perl/5.6.0 d:/perl/lib/site_perl . Environment for perl v5.6.0: HOME=d:\home\sthoenna LANG=en_us LANGUAGE (unset) LD_LIBRARY_PATH (unset) LOGDIR (unset) PATH=d:\bin;C:\OS2;d:\perl\bin;C:\OS2\SYSTEM;C:\OS2\INSTALL;C:\;C:\OS2\MDOS;C:\OS2\APPS;C:\MMOS2;d:\os2apps\util;d:\DOSAPPS\UTIL;c:\sio;D:\WINDOWS;d:\pdksh;d:\emx\bin;d:\emacs\19.33\bin;d:\ispell PERL_BADLANG (unset) PERL_SH_DIR=d:\BIN SHELL (unset) ```
p5pRT commented 23 years ago

From [Unknown Contact. See original ticket]

Yitzchak Scott-Thoennes writes​:

sub context { print wantarray ? 'list' : defined wantarray ? 'scalar' : 'void'} my @​x = scalar context; # works my $x = scalar context; # works scalar context; # doesn't work __END__ scalar scalar void

What bothers you? void context is a (kind of a) scalar context.

Ilya

p5pRT commented 23 years ago

From @simoncozens

The scalar operator does not change void context.

This is because Perl_scalarvoid makes the scalar operator impart void context on its children. This seems extremely wrong indeed.

Inline Patch ```diff --- ../op.c Tue May 30 03:45:39 2000 +++ op.c Tue May 30 03:42:21 2000 @@ -1160,7 +1160,6 @@ case OP_DBSTATE: case OP_ENTERTRY: case OP_ENTER: - case OP_SCALAR: if (!(o->op_flags & OPf_KIDS)) break; /* FALL THROUGH */ @@ -1179,6 +1178,7 @@ case OP_REQUIRE: /* all requires must return a boolean value */ o->op_flags &= ~OPf_WANT; + case OP_SCALAR: return scalar(o); case OP_SPLIT: if ((kid = cLISTOPo->op_first) && kid->op_type == OP_PUSHRE) { --- t/op/wantarray.t~ Tue May 30 03:48:07 2000 +++ t/op/wantarray.t Tue May 30 03:49:50 2000 @@ -1,6 +1,6 @@ #!./perl -print "1..3\n"; +print "1..7\n"; sub context { my ( $cona, $testnum ) = @_; my $conb = (defined wantarray) ? ( wantarray ? 'A' : 'S' ) : 'V'; @@ -13,4 +13,8 @@ context('V',1); $a = context('S',2); @a = context('A',3); +scalar context('S',4); +$a = scalar context('S',5); +($a) = context('A',6); +($a) = scalar context('S',7); 1; ---------------------------------------------------------------- ```

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p5pRT commented 23 years ago

From [Unknown Contact. See original ticket]

Created by @ysth

The scalar operator does not change void context.

[D​:\home\sthoenna]perl #!perl -wl sub context { print wantarray ? 'list' : defined wantarray ? 'scalar' : 'void'} my @​x = scalar context; # works my $x = scalar context; # works scalar context; # doesn't work __END__ scalar scalar void

Perl Info ``` Flags: category=core severity=medium Site configuration information for perl v5.6.0: Configured by sthoenna at Thu Mar 23 16:36:26 PST 2000. Summary of my perl5 (revision 5.0 version 6 subversion 0) configuration: Platform: osname=os2, osvers=2.30, archname=os2 uname='os2 efn.org 2 2.30 i386 ' config_args='-de -Dprefix=d:/perl -Aoptimize=-DDEBUGGING' 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='gcc', optimize='-O2 -fomit-frame-pointer -malign-loops=2 -malign-jumps=2 -malign-functions=2 -s -DDEBUGGING', gccversion=2.8.1 cppflags='-Zomf -Zmt -DDOSISH -DOS2=2 -DEMBED -I. -D_EMX_CRT_REV_=62' ccflags ='-Zomf -Zmt -DDOSISH -DOS2=2 -DEMBED -I. -D_EMX_CRT_REV_=62' 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=4 alignbytes=4, usemymalloc=y, prototype=define Linker and Libraries: ld='gcc', ldflags ='-Zexe -Zomf -Zmt -Zcrtdll -Zstack 32000' libpth=d:/emx/lib d:/emx/lib/mt libs=-lsocket -lm -lbsd libc=d:/emx/lib/mt/c_import.lib, so=dll, useshrplib=true, libperl=libperl.lib Dynamic Linking: dlsrc=dl_dlopen.xs, dlext=dll, d_dlsymun=undef, ccdlflags=' ' cccdlflags='-Zdll', lddlflags='-Zdll -Zomf -Zmt -Zcrtdll -s' Locally applied patches: @INC for perl v5.6.0: d:/perl/lib/5.6.0/os2 d:/perl/lib/5.6.0 d:/perl/lib/site_perl/5.6.0/os2 d:/perl/lib/site_perl/5.6.0 d:/perl/lib/site_perl . Environment for perl v5.6.0: HOME=d:\home\sthoenna LANG=en_us LANGUAGE (unset) LD_LIBRARY_PATH (unset) LOGDIR (unset) PATH=d:\bin;C:\OS2;d:\perl\bin;C:\OS2\SYSTEM;C:\OS2\INSTALL;C:\;C:\OS2\MDOS;C:\OS2\APPS;C:\MMOS2;d:\os2apps\util;d:\DOSAPPS\UTIL;c:\sio;D:\WINDOWS;d:\pdksh;d:\emx\bin;d:\emacs\19.33\bin;d:\ispell PERL_BADLANG (unset) PERL_SH_DIR=d:\BIN SHELL (unset) ```