Documentation for split uses single quotes for PATTERN parameter #14802

p5pRT · 2015-07-13T12:09:40Z

Migrated from rt.perl.org#125605 (status was 'open')

Searchable as RT125605$

p5pRT · 2015-07-13T12:09:40Z

From [email protected]

This is a bug report for perl from the.rob.dixon@gmail.com,
generated with the help of perlbug 1.40 running under perl 5.22.0.

The contents of `perlfunc` relating to `split` uses single quotes
and slashes indiscriminately to delimit the first PATTERN parameter.

I suggest that this is contrary to currently-favoured best practice,
and the delimiters should be slashes throughout, except for the
special case of a single space

There are solid reasons why this is the preferred form:

- The PATTERN behaves as a regular expression, so '.' will match any
character (and produce an empty list). That is made much clearer by
using /./ instead

- A single literal space ' ' is different from a regular expression
/ / containing the same string. It therefore seems best to use t

he
form that corresponds to the actual behaviour for any other value

- The PATTERN is processed again as a regular expression, so one may
expect a split on the two-character string '\t' to be different from
using the one-character string "\t". In practice the two are
identical because of the secondary processing

Flags:
category=docs
severity=low

Site configuration information for perl 5.22.0:

Configured by strawberry-perl at Mon Jun 1 20:06:45 2015.

Summary of my perl5 (revision 5 version 22 subversion 0) configuration:

Platform:
osname=MSWin32, osvers=6.3, archname=MSWin32-x86-multi-thread-64int
uname='Win32 strawberry-perl 5.22.0.1 #1 Mon Jun 1 20:04:50 2015 i386'
config_args='undef'
hint=recommended, useposix=true, d_sigaction=undef
useithreads=define, usemultiplicity=define
use64bitint=define, use64bitall=undef, uselongdouble=undef
usemymalloc=n, bincompat5005=undef
Compiler:
cc='gcc', ccflags =' -s -O2 -DWIN32 -DPERL_TEXTMODE_SCRIPTS
-DPERL_IMPLICIT_CONTEXT -DPERL_IMPLICIT_SYS -fwrapv -fno-strict-aliasing
-mms-bitfields',
optimize='-s -O2',
cppflags='-DWIN32'
ccversion='', gccversion='4.9.2', gccosandvers=''
intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=12345678,
doublekind=3
d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=8,
longdblkind=3
ivtype='long long', ivsize=8, nvtype='double', nvsize=8, Off_t='long
long', lseeksize=8
alignbytes=8, prototype=define
Linker and Libraries:
ld='g++', ldflags ='-s -L"C:\STRAWB1\perl\lib\CORE"
-L"C:\STRAWB1\c\lib"'
libpth=C:\STRAWB~~1\c\lib C:\STRAWB~~1\c\i686-w64-mingw32\lib
C:\STRAWB1\c\lib\gcc\i686-w64-mingw32\4.9.2
libs=-lmoldname -lkernel32 -luser32 -lgdi32 -lwinspool -lcomdlg32
-ladvapi32 -lshell32 -lole32 -loleaut32 -lnetapi32 -luuid -lws2_32 -lmpr
-lwinmm -lversion -lodbc32 -lodbccp32 -lcomctl32
perllibs=-lmoldname -lkernel32 -luser32 -lgdi32 -lwinspool -lcomdlg32
-ladvapi32 -lshell32 -lole32 -loleaut32 -lnetapi32 -luuid -lws2_32 -lmpr
-lwinmm -lversion -lodbc32 -lodbccp32 -lcomctl32
libc=, so=dll, useshrplib=true, libperl=libperl522.a
gnulibc_version=''
Dynamic Linking:
dlsrc=dl_win32.xs, dlext=xs.dll, d_dlsymun=undef, ccdlflags=' '
cccdlflags=' ', lddlflags='-mdll -s -L"C:\STRAWB1\perl\lib\CORE"
-L"C:\STRAWB~1\c\lib"'

@INC for perl 5.22.0:
C:/Strawberry/perl/site/lib/MSWin32-x86-multi-thread-64int
C:/Strawberry/perl/site/lib
C:/Strawberry/perl/vendor/lib
C:/Strawberry/perl/lib
.

Environment for perl 5.22.0:
HOME (unset)
LANG (unset)
LANGUAGE (unset)
LD_LIBRARY_PATH (unset)
LOGDIR (unset)
PATH=C:\Python27\;C:\Python27\Scripts;C:\Program Files (x86)\Common
Files\Intel\Shared
Files\cpp\bin\Intel64;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Strawberry\c\bin;C:\Strawberry\perl\site\bin;C:\Strawberry\perl\bin;C:\ffmpeg\bin;C:\Program
Files (x86)\Git\cmd;C:\Program Files (x86)\NVIDIA
Corporation\PhysX\Common;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;C:\WINDOWS\System32\WindowsPowerShell\v1.0\
PERL_BADLANG (unset)
SHELL (unset)

p5pRT · 2015-07-13T22:41:01Z

From @jkeenan

On Mon Jul 13 05:09:40 2015, the.rob.dixon@gmail.com wrote:

This is a bug report for perl from the.rob.dixon@gmail.com,
generated with the help of perlbug 1.40 running under perl 5.22.0.

-----------------------------------------------------------------

The contents of `perlfunc` relating to `split` uses single quotes
and slashes indiscriminately to delimit the first PATTERN parameter.

I suggest that this is contrary to currently-favoured best practice,
and the delimiters should be slashes throughout, except for the
special case of a single space

There are solid reasons why this is the preferred form:

- The PATTERN behaves as a regular expression, so '.' will match any
character (and produce an empty list). That is made much clearer by
using /./ instead

- A single literal space ' ' is different from a regular expression
/ / containing the same string. It therefore seems best to use t
he
form that corresponds to the actual behaviour for any other value

- The PATTERN is processed again as a regular expression, so one may
expect a split on the two-character string '\t' to be different from
using the one-character string "\t". In practice the two are
identical because of the secondary processing

Would you be willing and able to supply a patch which implements your recommendation? If so, please attach it to this RT or to an email response.

Thank you very much.

-----------------------------------------------------------------
---
Flags:
category=docs
severity=low
---
Site configuration information for perl 5.22.0:

Configured by strawberry-perl at Mon Jun 1 20:06:45 2015.

Summary of my perl5 (revision 5 version 22 subversion 0)
configuration:

Platform:
osname=MSWin32, osvers=6.3, archname=MSWin32-x86-multi-thread-64int
uname='Win32 strawberry-perl 5.22.0.1 #1 Mon Jun 1 20:04:50 2015
i386'
config_args='undef'
hint=recommended, useposix=true, d_sigaction=undef
useithreads=define, usemultiplicity=define
use64bitint=define, use64bitall=undef, uselongdouble=undef
usemymalloc=n, bincompat5005=undef
Compiler:
cc='gcc', ccflags =' -s -O2 -DWIN32 -DPERL_TEXTMODE_SCRIPTS
-DPERL_IMPLICIT_CONTEXT -DPERL_IMPLICIT_SYS -fwrapv -fno-strict-
aliasing
-mms-bitfields',
optimize='-s -O2',
cppflags='-DWIN32'
ccversion='', gccversion='4.9.2', gccosandvers=''
intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=12345678,
doublekind=3
d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=8,
longdblkind=3
ivtype='long long', ivsize=8, nvtype='double', nvsize=8, Off_t='long
long', lseeksize=8
alignbytes=8, prototype=define
Linker and Libraries:
ld='g++', ldflags ='-s -L"C:\STRAWB1\perl\lib\CORE"
-L"C:\STRAWB1\c\lib"'
libpth=C:\STRAWB~~1\c\lib C:\STRAWB~~1\c\i686-w64-mingw32\lib
C:\STRAWB1\c\lib\gcc\i686-w64-mingw32\4.9.2
libs=-lmoldname -lkernel32 -luser32 -lgdi32 -lwinspool -lcomdlg32
-ladvapi32 -lshell32 -lole32 -loleaut32 -lnetapi32 -luuid -lws2_32
-lmpr
-lwinmm -lversion -lodbc32 -lodbccp32 -lcomctl32
perllibs=-lmoldname -lkernel32 -luser32 -lgdi32 -lwinspool
-lcomdlg32
-ladvapi32 -lshell32 -lole32 -loleaut32 -lnetapi32 -luuid -lws2_32
-lmpr
-lwinmm -lversion -lodbc32 -lodbccp32 -lcomctl32
libc=, so=dll, useshrplib=true, libperl=libperl522.a
gnulibc_version=''
Dynamic Linking:
dlsrc=dl_win32.xs, dlext=xs.dll, d_dlsymun=undef, ccdlflags=' '
cccdlflags=' ', lddlflags='-mdll -s -L"C:\STRAWB1\perl\lib\CORE"
-L"C:\STRAWB~1\c\lib"'

---
@INC for perl 5.22.0:
C:/Strawberry/perl/site/lib/MSWin32-x86-multi-thread-64int
C:/Strawberry/perl/site/lib
C:/Strawberry/perl/vendor/lib
C:/Strawberry/perl/lib
.

---
Environment for perl 5.22.0:
HOME (unset)
LANG (unset)
LANGUAGE (unset)
LD_LIBRARY_PATH (unset)
LOGDIR (unset)
PATH=C:\Python27\;C:\Python27\Scripts;C:\Program Files
(x86)\Common
Files\Intel\Shared
Files\cpp\bin\Intel64;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Strawberry\c\bin;C:\Strawberry\perl\site\bin;C:\Strawberry\perl\bin;C:\ffmpeg\bin;C:\Program
Files (x86)\Git\cmd;C:\Program Files (x86)\NVIDIA
Corporation\PhysX\Common;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;C:\WINDOWS\System32\WindowsPowerShell\v1.0\
PERL_BADLANG (unset)
SHELL (unset)

--
James E Keenan (jkeenan@cpan.org)

p5pRT · 2015-07-13T22:41:01Z

The RT System itself - Status changed from 'new' to 'open'

khwilliamson · 2025-05-05T19:04:21Z

I searched in perlfunc from blead just now, and the only occurrences of a non slash delimiter are in fact for the special case of a single space

p5pRT added the Severity Low label Oct 19, 2019

xenu removed the Severity Low label Dec 29, 2021

khwilliamson closed this as completed May 5, 2025

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Documentation for split uses single quotes for PATTERN parameter #14802

Documentation for split uses single quotes for PATTERN parameter #14802

p5pRT commented Jul 13, 2015

p5pRT commented Jul 13, 2015

p5pRT commented Jul 13, 2015

p5pRT commented Jul 13, 2015

khwilliamson commented May 5, 2025

Documentation for split uses single quotes for PATTERN parameter #14802

Documentation for split uses single quotes for PATTERN parameter #14802

Comments

p5pRT commented Jul 13, 2015

p5pRT commented Jul 13, 2015

From [email protected]

p5pRT commented Jul 13, 2015

From @jkeenan

p5pRT commented Jul 13, 2015

khwilliamson commented May 5, 2025