Documentation for split uses single quotes for PATTERN parameter

[p5pRT]

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

Searchable as RT125605$

[p5pRT]

From the.rob.dixon@gmail.com

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​:\STRAWB1\c\lib C​:\STRAWB1\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]

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​:\STRAWB1\c\lib C​:\STRAWB1\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]

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

[khwilliamson]

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