evalexpr?evaltrue:evalfalse would like evaltrue defaulted by evalexpr

p5pRT commented 24 years ago

Migrated from rt.perl.org#3559 (status was 'resolved')

Searchable as RT3559$

p5pRT commented 24 years ago

From mar@cf.nettuno.it

This is a bug report for perl from mar@cf.nettuno.it\, generated with the help of perlbug 1.28 running under perl v5.6.0.

This is not a bug\, but an usefull and easy enhancement -i think: the syntax and use of evalexpr?evaltruecase:evalfalsecase can be enhanced with the capability of absence of evaltruecase expression

this absence can return by default the value of evalexpr

having evalexpr?:evalfalsecase similar but more efficient that (typical...) evalexpr?evalexpr:evalfalsecase

actually perl returns syntax error near "?:"

for efficency and code more light

All the best\, Marco Munari \mar@chiara\.dei\.unipd\.it -- /~v~~\ .::: ... Marco Munari ... ::::::::::::::::::: Univers. :::. \_ */ ::: mailto:mar@cf.nettuno.it?subject=.signature :: .\..\. :: :: \A ...::: :: YV ::: "Progress is implicitly due to perfect exceptions" ::: / \ ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::. x(t)\,y(t) = th(3t-34.5)*e^[-(3t-34.5)^2]/2-4.3+e^(-1.8/t^2)/(.8*atg(t- 3)+2)(t-1.8)-.3th(5t-42.5)\,(1.4e^[-(3t-34.5)^2]+1-sgn[|t-8.5|-.5]*1.5* |sin(pi*t)|^[2e^(-(t-11.5)^2)+.5+e^(-(.6t-3.3)^2)])/(.5+t)+1 ; 0\<t\<14

Flags: category=core severity=none

Site configuration information for perl v5.6.0:

Configured by pixel at Fri Mar 31 16:32:49 CEST 2000.

Summary of my perl5 (revision 5.0 version 6 subversion 0) configuration: Platform: osname=linux\, osvers=2.2.15-0.16mdksmp\, archname=i386-linux uname='linux kenobi.mandrakesoft.com 2.2.15-0.16mdksmp #1 smp mon mar 13 16:40:10 cet 2000 i686 unknown ' config_args='-des -Dprefix=/usr -Darchname=i386-linux -Dd_dosuid -Dd_semctl_semun -Di_db -Di_ndbm -Di_gdbm -Ud_csh -Dman3dir=/usr/lib/perl5/man/man3 -Doptimize=-O3 -fomit-frame-pointer -fno-exceptions -fno-rtti -pipe -s -mpentium -mcpu=pentium -march=pentium -ffast-math -fexpensive-optimizations' 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='-O3 -fomit-frame-pointer -fno-exceptions -fno-rtti -pipe -s -mpentium -mcpu=pentium -march=pentium -ffast-math -fexpensive-optimizations'\, gccversion=2.95.3 19991030 (prerelease) cppflags='-fno-strict-aliasing' ccflags ='-fno-strict-aliasing -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 -lposix -lcrypt libc=/lib/libc-2.1.3.so\, 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'

Locally applied patches:

@INC for perl v5.6.0: /usr/lib/perl5/5.6.0/i386-linux /usr/lib/perl5/5.6.0 /usr/lib/perl5/site_perl/5.6.0/i386-linux /usr/lib/perl5/site_perl/5.6.0 /usr/lib/perl5/site_perl/5.005/i386-linux /usr/lib/perl5/site_perl/5.005 /usr/lib/perl5/site_perl .

Environment for perl v5.6.0: HOME=/home/mar LANG=en LANGUAGE=en LC_ALL=en LD_LIBRARY_PATH (unset) LOGDIR (unset) PATH=/usr/local/bin:/bin:/usr/bin:/opt/jdk-1.2.2/bin:/usr/X11R6/bin:/home/mar/bin:/opt/jdk-1.2.2/bin:/usr/X11R6/bin PERL_BADLANG (unset) SHELL=/bin/bash

p5pRT commented 24 years ago

From [Unknown Contact. See original ticket]

Marco Munari \mar@cf\.nettuno\.it wrote

having evalexpr?:evalfalsecase similar but more efficient that (typical...) evalexpr?evalexpr:evalfalsecase

The || operator already does exactly what you are asking for.

Mike Guy

p5pRT commented 24 years ago

From [Unknown Contact. See original ticket]

On 20 Jul 2000\, Marco Munari wrote:

having evalexpr?:evalfalsecase similar but more efficient that (typical...) evalexpr?evalexpr:evalfalsecase

perhaps you want the equivalent (and currently legal):

$val = evalexpr || evalfalsecase;

-Aaron

p5pRT commented 24 years ago

From @ysth

In article \Pine\.A41\.4\.05\.10007210845000\.67816\-100000@node13\.unix\.Virginia\.EDU\, Aaron J Mackey \ajm6q@virginia\.edu wrote:

On 20 Jul 2000\, Marco Munari wrote:

having evalexpr?:evalfalsecase similar but more efficient that (typical...) evalexpr?evalexpr:evalfalsecase

perhaps you want the equivalent (and currently legal):
$val = evalexpr || evalfalsecase;

Subtle difference: C\<a ? a : b> gives boolean context to the first a. The second a and the b get whatever context comes from the outside. C\<a || b> gives scalar context to the a\, while b gets its context from the outside.

Perl / perl5