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# New Ticket Created by Zefram
# Please include the string: [perl #132607]
# in the subject line of all future correspondence about this issue.
# <URL: https://rt.perl.org/Ticket/Display.html?id=132607 >
This is a bug report for perl from zefram@fysh.org,
generated with the help of perlbug 1.41 running under perl 5.27.6.
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[Please describe your issue here]
It would be nice for Perl to understand chained comparisons such as "$a
le $b lt $c", which would mean "$a le $b && $b lt $c" but with only a
single evaluation of the middle comparand. The comparison operators are
currently non-associative, so most of what ought to be chained comparisons
are currently syntax errors. Introducing chained comparisons would not
change the meaning of any currently-legal expression.
One wrinkle: we currently have two levels of precedence for comparison
operators, one for "lt" et al, and a looser one for "eq" et al. So "$a lt
$b eq $c" is currently legal. This is imitating the C precedence levels,
I think mainly so that "!=" can be used to mean "xor". It's already a
bit of a gotcha, and we'd have to warn that things like that don't make
chained comparisons.
[Please do not change anything below this line]
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---
Flags:
category=core
severity=wishlist
---
Site configuration information for perl 5.27.6:
Configured by zefram at Tue Nov 21 05:42:59 GMT 2017.
Summary of my perl5 (revision 5 version 27 subversion 6) configuration:
Platform:
osname=linux
osvers=3.16.0-4-amd64
archname=x86_64-linux-thread-multi
uname='linux barba.rous.org 3.16.0-4-amd64 #1 smp debian 3.16.43-2+deb8u2 (2017-06-26) x86_64 gnulinux '
config_args='-des -Dprefix=/home/zefram/usr/perl/perl_install/perl-5.27.6-i64-f52 -Duselargefiles -Dusethreads -Uafs -Ud_csh -Uusesfio -Uusenm -Duseshrplib -Dusedevel -Uversiononly -Ui_db'
hint=recommended
useposix=true
d_sigaction=define
useithreads=define
usemultiplicity=define
use64bitint=define
use64bitall=define
uselongdouble=undef
usemymalloc=n
default_inc_excludes_dot=define
bincompat5005=undef
Compiler:
cc='cc'
ccflags ='-D_REENTRANT -D_GNU_SOURCE -fwrapv -fno-strict-aliasing -pipe -fstack-protector-strong -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -D_FORTIFY_SOURCE=2'
optimize='-O2'
cppflags='-D_REENTRANT -D_GNU_SOURCE -fwrapv -fno-strict-aliasing -pipe -fstack-protector-strong -I/usr/local/include'
ccversion=''
gccversion='4.9.2'
gccosandvers=''
intsize=4
longsize=8
ptrsize=8
doublesize=8
byteorder=12345678
doublekind=3
d_longlong=define
longlongsize=8
d_longdbl=define
longdblsize=16
longdblkind=3
ivtype='long'
ivsize=8
nvtype='double'
nvsize=8
Off_t='off_t'
lseeksize=8
alignbytes=8
prototype=define
Linker and Libraries:
ld='cc'
ldflags =' -fstack-protector-strong -L/usr/local/lib'
libpth=/usr/local/lib /usr/lib/gcc/x86_64-linux-gnu/4.9/include-fixed /usr/include/x86_64-linux-gnu /usr/lib /lib/x86_64-linux-gnu /lib/../lib /usr/lib/x86_64-linux-gnu /usr/lib/../lib /lib
libs=-lpthread -lnsl -ldb -ldl -lm -lcrypt -lutil -lc
perllibs=-lpthread -lnsl -ldl -lm -lcrypt -lutil -lc
libc=libc-2.19.so
so=so
useshrplib=true
libperl=libperl.so
gnulibc_version='2.19'
Dynamic Linking:
dlsrc=dl_dlopen.xs
dlext=so
d_dlsymun=undef
ccdlflags='-Wl,-E -Wl,-rpath,/home/zefram/usr/perl/perl_install/perl-5.27.6-i64-f52/lib/5.27.6/x86_64-linux-thread-multi/CORE'
cccdlflags='-fPIC'
lddlflags='-shared -O2 -L/usr/local/lib -fstack-protector-strong'
---
@INC for perl 5.27.6:
/home/zefram/usr/perl/perl_install/perl-5.27.6-i64-f52/lib/site_perl/5.27.6/x86_64-linux-thread-multi
/home/zefram/usr/perl/perl_install/perl-5.27.6-i64-f52/lib/site_perl/5.27.6
/home/zefram/usr/perl/perl_install/perl-5.27.6-i64-f52/lib/5.27.6/x86_64-linux-thread-multi
/home/zefram/usr/perl/perl_install/perl-5.27.6-i64-f52/lib/5.27.6
---
Environment for perl 5.27.6:
HOME=/home/zefram
LANG (unset)
LANGUAGE (unset)
LD_LIBRARY_PATH (unset)
LOGDIR (unset)
PATH=/home/zefram/usr/perl/perl_install/perl-5.27.6-i64-f52/bin:/home/zefram/usr/perl/util:/home/zefram/pub/x86_64-unknown-linux-gnu/bin:/home/zefram/pub/common/bin:/usr/bin:/bin:/usr/local/bin:/usr/games
PERL_BADLANG (unset)
SHELL=/usr/bin/zsh
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