Re^5: RFC: "assignary" operator ?= :

When and why does this ever happen???

As for why, I don't know. But it does. On this old debian box:

qwurx [shmem] ~> libdirs=`perl -E 'say for @INC'`
qwurx [shmem] ~> perl -lne 'print "$ARGV: $_" if /\$(\w+)\s+=\s+\$\1\s
+*\?/' `(for d in $libdirs; do find $d -type f; done)`
/usr/local/share/perl/5.20.2/Parse/Eyapp/Treeregexp.pm:   $semantic = 
+$semantic? $semantic->{attr} : undef;
/usr/local/share/perl/5.20.2/Parse/Eyapp/Treeregexp.pm:   $semantic = 
+$semantic? $semantic->{attr} : undef;
/usr/local/share/perl/5.20.2/Parse/Eyapp/Treeregexp.pm:   $semantic = 
+$semantic? $semantic->{attr} : undef;
/usr/local/share/perl/5.20.2/Parse/Eyapp/Treeregexp.pm:   $semantic = 
+$semantic? $semantic->{attr} : undef;
/usr/local/share/perl/5.20.2/Parse/Eyapp/Treeregexp.yp:   $semantic = 
+$semantic? $semantic->{attr} : undef;
/usr/local/share/perl/5.20.2/Parse/Eyapp/Treeregexp.yp:   $semantic = 
+$semantic? $semantic->{attr} : undef;
/usr/local/share/perl/5.20.2/Parse/Eyapp/Treeregexp.yp:   $semantic = 
+$semantic? $semantic->{attr} : undef;
/usr/local/share/perl/5.20.2/Parse/Eyapp/Treeregexp.yp:   $semantic = 
+$semantic? $semantic->{attr} : undef;
/usr/local/share/perl/5.20.2/Parse/Eyapp/eyapp: $opt_s = $opt_s ? 1 : 
+0;
/usr/local/share/perl/5.20.2/Parse/Eyapp/eyapp: $opt_n = $opt_n ? 0 : 
+1;
/usr/local/share/perl/5.20.2/Net/EmptyPort.pm:     $proto = $proto ? l
+c($proto) : 'tcp';
/usr/local/share/perl/5.20.2/Net/EmptyPort.pm:     $proto = $proto ? l
+c($proto) : 'tcp';
/usr/local/share/perl/5.20.2/Net/EmptyPort.pm:     $proto = $proto ? l
+c($proto) : 'tcp';
Can't open /usr/local/share/perl/5.20.2/.Inline.pm.swp: Permission den
+ied at -e line 1, <> line 524147.
/usr/local/share/perl/5.20.2/ExtUtils/ParseXS.pm:     $externC = $exte
+rnC ? qq[extern "C"] : "";
/usr/local/share/perl/5.20.2/Test/Builder/Tester.pm:         $got = $g
+ot ? "$got\n$g" : $g;
/usr/local/share/perl/5.20.2/Test/Builder/Tester.pm:         $wanted =
+ $wanted ? "$wanted\n$w" : $w;
/usr/local/share/perl/5.20.2/Test/Builder.pm:     $test = $test ? 1 : 
+0;
/usr/local/share/perl/5.20.2/Test/Tester/Capture.pm:     $test = $test
+ ? 1 : 0;
/usr/local/share/perl/5.20.2/Test2/Compare/Bool.pm:     $match = $matc
+h ? 0 : 1 if $self->{+NEGATE};
/usr/lib/x86_64-linux-gnu/perl5/5.20/Template/Provider.pm:     $parser
+ = $parser ? $parser->_dump() : '<no parser>';
/usr/lib/x86_64-linux-gnu/perl5/5.20/Template/Provider.pm:            
+ $prev = $prev ? "#$lut->{ $prev }<-": '<undef>';
/usr/lib/x86_64-linux-gnu/perl5/5.20/Template/Provider.pm:            
+ $next = $next ? "->#$lut->{ $next }": '<undef>';
/usr/lib/x86_64-linux-gnu/perl5/5.20/Template/Directive.pm:     $line 
+= $line ? " (starting line $line)" : '';
/usr/lib/x86_64-linux-gnu/perl5/5.20/Template/Directive.pm:     $args 
+= $args ? "$args, $alias" : ", undef, $alias"
/usr/lib/x86_64-linux-gnu/perl5/5.20/DBI/SQL/Nano.pm:     if ($neg) { 
+$match = $match ? 0 : 1; }
/usr/share/perl5/SQL/Translator/Producer/Oracle.pm:                 $i
+ndex_name = $index_name ? mk_name( $index_name )
/usr/share/perl5/SQL/Translator/Producer/Oracle.pm:                 $i
+ndex_name = $index_name ? mk_name( $index_name )
/usr/share/perl5/SQL/Translator/Producer/Oracle.pm:                 $i
+ndex_name = $index_name ? mk_name( $index_name )
/usr/share/perl5/SQL/Translator/Producer/Oracle.pm:                 $d
+efault = $default ? "'1'" : "'0'";
/usr/share/perl5/SQL/Abstract.pm:   $sql = $sql ? $self->_sqlcase(' wh
+ere ') . "( $sql )" : '';
/usr/share/perl5/Parse/RecDescent.pm:             $lookahead = $lookah
+ead ? -$lookahead : -1;
/usr/share/perl5/Parse/RecDescent.pm:             $lookahead = $lookah
+ead ? $lookahead : 1;
/usr/share/perl5/HTTP/Cookies/Netscape.pm:     $expires = $expires ? $
+expires - $HTTP::Cookies::EPOCH_OFFSET : 0;
/usr/share/perl5/HTTP/Cookies/Netscape.pm:     $secure = $secure ? "TR
+UE" : "FALSE";
/usr/share/perl5/Config/Tiny.pm:     $encoding    = $encoding ? "<:$en
+coding" : '<';
/usr/share/perl5/Config/Tiny.pm:     $encoding    = $encoding ? ">:$en
+coding" : '>';
/usr/share/perl5/Mojo/DOM.pm:   $start  = $start  ? ($#$tree + 1) : _s
+tart($tree);
/usr/share/perl5/Mojo/DOM.pm:   $offset = $offset ? $#$tree       : 0;
/usr/share/perl5/Font/TTF/OldMort.pm:                         $_ = $_ 
+? $_ - ($mappingTables / 2) : undef;
/usr/share/perl5/Font/TTF/Mort/Contextual.pm:             $_ = $_ ? $_
+ - ($mappingTables / 2) : undef;
/usr/share/perl5/Net/EmptyPort.pm:         $proto = $proto ? lc($proto
+) : 'tcp';
/usr/share/perl5/Net/EmptyPort.pm:         $proto = $proto ? lc($proto
+) : 'tcp';
/usr/share/perl5/Net/SNMP/Transport/IPv6.pm:    $s = $s ? sprintf('%%%
+u', $s) : q{};
/usr/share/perl5/Net/SNMP/Transport/IPv6.pm:    $s = $s ? pack('N', $s
+) : q{};
/usr/share/perl5/UNIVERSAL/isa.pm:     $extra = $extra ? " ($extra)" :
+ '';
/usr/share/perl5/IO/Socket/Socks.pm:     $status = $status ? AUTHREPLY
+_SUCCESS : 1; #XXX AUTHREPLY_FAILURE broken
/usr/share/perl5/Text/CSV_PP.pm:         $v =~ m/^[0-9]/ or $v = $v ? 
+1 : 0; # default for true/false
/usr/share/perl5/Text/CSV_PP.pm:         $v =~ m/^[0-9]/ or $v = $v ? 
+1 : 0; # default for true/false
/usr/share/perl5/Lintian/Tags.pm:                     $found = $found 
+? 0 : 1;
/usr/share/perl5/Excel/Writer/XLSX/Drawing.pm:     $underline = $under
+line ? 'sng' : 'none';
/usr/share/perl5/Excel/Writer/XLSX/Drawing.pm:     $strike = $strike ?
+ 'Strike' : 'noStrike';
/usr/share/perl5/Test/Toolbox.pm:     $is = $is ? 'true' : 'false';
/usr/share/perl5/Test/Toolbox.pm:     $should = $should ? 'true' : 'fa
+lse';
/usr/share/perl5/Test/Toolbox.pm:     $ok = $ok ? 1 : 0;
/usr/share/perl5/Spreadsheet/WriteExcel/Worksheet.pm:         $visible
+ = $visible                   ? 0x0000 : 0x0002;
/usr/share/perl5/Spreadsheet/WriteExcel/Worksheet.pm:         $visible
+ = $visible                   ? 0x0002 : 0x0000;
/usr/share/perl5/Spreadsheet/ParseExcel/Utility.pm:             $doubl
+e_quote = $double_quote ? 0 : 1;
/usr/share/perl5/Spreadsheet/XLSX/Utility2007.pm:             $iDblQ =
+ $iDblQ? 0: 1;
/usr/share/perl5/Zoidberg/StringParser.pm:                 $expr = $ex
+pr ? '('.$expr.')|' : '';
/usr/share/perl5/Image/ExifTool/QuickTime.pm:         $lang = $lang ? 
+"($lang) " : '';
/usr/share/perl5/Image/ExifTool/QuickTime.pm:             $lang = $lan
+g ? "($lang) " : '';
/usr/share/perl5/Image/ExifTool/QuickTime.pm:             $lang = $lan
+g ? "($lang) " : '';
/usr/share/perl5/Image/ExifTool/QuickTime.pm:             $lang = $lan
+g ? "($lang) " : '';
/usr/share/perl5/Image/ExifTool/QuickTime.pm:             $lang = $lan
+g ? "($lang) " : '';
/usr/share/perl5/Image/ExifTool/XMPStruct.pl:         $delim = $delim 
+? "\\$delim|,|\\||\$" : ',|\\||$';
/usr/share/perl5/Image/ExifTool/BuildTagLookup.pm:             $rowCla
+ss = $rowClass ? '' : " class=b";
/usr/share/perl5/Image/ExifTool/ASF.pm:             $_ = $_ ? 'True' :
+ 'False';
/usr/share/perl5/Image/ExifTool.pm:     $tagInfo = $tagInfo ? { Name =
+> $tagInfo } : { } unless ref $tagInfo eq 'HASH';
/usr/share/perl5/Type/Params.pm:             $constraint = $constraint
+ ? Any : Optional[Any];
/usr/share/perl5/CGI/Compile.pm:     $proto = $proto ? "($proto)" : ''
+;
/usr/share/perl5/assert.pl:     $w = $w ? '@ = ' : '$ = ';
/usr/share/perl5/IPC/Run.pm:    $r = $r ? '' : " ERROR $!";
/usr/share/perl5/IPC/Run.pm:                $out = $out ? 'b' : 'w'   
+     if vec( $self->{WIN}, $_, 1 );
/usr/share/perl5/IPC/Run.pm:                $out = $out ? uc( $out ) :
+ 'x' if vec( $self->{EIN}, $_, 1 );
/usr/share/perl5/IPC/Run.pm:                $out = $out ? 'b' : 'w'   
+     if vec( $self->{WOUT}, $_, 1 );
/usr/share/perl5/IPC/Run.pm:                $out = $out ? uc( $out ) :
+ 'x' if vec( $self->{EOUT}, $_, 1 );
/usr/share/perl5/AppConfig/State.pm:         $value = $value ? 0 : 1 i
+f $negate;
./SQL/Translator/Producer/Oracle.pm:                 $index_name = $in
+dex_name ? mk_name( $index_name )
./SQL/Translator/Producer/Oracle.pm:                 $index_name = $in
+dex_name ? mk_name( $index_name )
./SQL/Translator/Producer/Oracle.pm:                 $index_name = $in
+dex_name ? mk_name( $index_name )
./SQL/Translator/Producer/Oracle.pm:                 $default = $defau
+lt ? "'1'" : "'0'";
./SQL/Abstract.pm:   $sql = $sql ? $self->_sqlcase(' where ') . "( $sq
+l )" : '';
./Parse/RecDescent.pm:             $lookahead = $lookahead ? -$lookahe
+ad : -1;
./Parse/RecDescent.pm:             $lookahead = $lookahead ? $lookahea
+d : 1;
./HTTP/Cookies/Netscape.pm:     $expires = $expires ? $expires - $HTTP
+::Cookies::EPOCH_OFFSET : 0;
./HTTP/Cookies/Netscape.pm:     $secure = $secure ? "TRUE" : "FALSE";
./Config/Tiny.pm:     $encoding    = $encoding ? "<:$encoding" : '<';
./Config/Tiny.pm:     $encoding    = $encoding ? ">:$encoding" : '>';
./Mojo/DOM.pm:   $start  = $start  ? ($#$tree + 1) : _start($tree);
./Mojo/DOM.pm:   $offset = $offset ? $#$tree       : 0;
./Font/TTF/OldMort.pm:                         $_ = $_ ? $_ - ($mappin
+gTables / 2) : undef;
./Font/TTF/Mort/Contextual.pm:             $_ = $_ ? $_ - ($mappingTab
+les / 2) : undef;
./Net/EmptyPort.pm:         $proto = $proto ? lc($proto) : 'tcp';
./Net/EmptyPort.pm:         $proto = $proto ? lc($proto) : 'tcp';
./Net/SNMP/Transport/IPv6.pm:    $s = $s ? sprintf('%%%u', $s) : q{};
./Net/SNMP/Transport/IPv6.pm:    $s = $s ? pack('N', $s) : q{};
./UNIVERSAL/isa.pm:     $extra = $extra ? " ($extra)" : '';
./IO/Socket/Socks.pm:     $status = $status ? AUTHREPLY_SUCCESS : 1; #
+XXX AUTHREPLY_FAILURE broken
./Text/CSV_PP.pm:         $v =~ m/^[0-9]/ or $v = $v ? 1 : 0; # defaul
+t for true/false
./Text/CSV_PP.pm:         $v =~ m/^[0-9]/ or $v = $v ? 1 : 0; # defaul
+t for true/false
./Lintian/Tags.pm:                     $found = $found ? 0 : 1;
./Excel/Writer/XLSX/Drawing.pm:     $underline = $underline ? 'sng' : 
+'none';
./Excel/Writer/XLSX/Drawing.pm:     $strike = $strike ? 'Strike' : 'no
+Strike';
./Test/Toolbox.pm:     $is = $is ? 'true' : 'false';
./Test/Toolbox.pm:     $should = $should ? 'true' : 'false';
./Test/Toolbox.pm:     $ok = $ok ? 1 : 0;
./Spreadsheet/WriteExcel/Worksheet.pm:         $visible = $visible    
+               ? 0x0000 : 0x0002;
./Spreadsheet/WriteExcel/Worksheet.pm:         $visible = $visible    
+               ? 0x0002 : 0x0000;
./Spreadsheet/ParseExcel/Utility.pm:             $double_quote = $doub
+le_quote ? 0 : 1;
./Spreadsheet/XLSX/Utility2007.pm:             $iDblQ = $iDblQ? 0: 1;
./Zoidberg/StringParser.pm:                 $expr = $expr ? '('.$expr.
+')|' : '';
./Image/ExifTool/QuickTime.pm:         $lang = $lang ? "($lang) " : ''
+;
./Image/ExifTool/QuickTime.pm:             $lang = $lang ? "($lang) " 
+: '';
./Image/ExifTool/QuickTime.pm:             $lang = $lang ? "($lang) " 
+: '';
./Image/ExifTool/QuickTime.pm:             $lang = $lang ? "($lang) " 
+: '';
./Image/ExifTool/QuickTime.pm:             $lang = $lang ? "($lang) " 
+: '';
./Image/ExifTool/XMPStruct.pl:         $delim = $delim ? "\\$delim|,|\
+\||\$" : ',|\\||$';
./Image/ExifTool/BuildTagLookup.pm:             $rowClass = $rowClass 
+? '' : " class=b";
./Image/ExifTool/ASF.pm:             $_ = $_ ? 'True' : 'False';
./Image/ExifTool.pm:     $tagInfo = $tagInfo ? { Name => $tagInfo } : 
+{ } unless ref $tagInfo eq 'HASH';
./Type/Params.pm:             $constraint = $constraint ? Any : Option
+al[Any];
./CGI/Compile.pm:     $proto = $proto ? "($proto)" : '';
./assert.pl:     $w = $w ? '@ = ' : '$ = ';
./IPC/Run.pm:    $r = $r ? '' : " ERROR $!";
./IPC/Run.pm:                $out = $out ? 'b' : 'w'        if vec( $s
+elf->{WIN}, $_, 1 );
./IPC/Run.pm:                $out = $out ? uc( $out ) : 'x' if vec( $s
+elf->{EIN}, $_, 1 );
./IPC/Run.pm:                $out = $out ? 'b' : 'w'        if vec( $s
+elf->{WOUT}, $_, 1 );
./IPC/Run.pm:                $out = $out ? uc( $out ) : 'x' if vec( $s
+elf->{EOUT}, $_, 1 );
./AppConfig/State.pm:         $value = $value ? 0 : 1 if $negate;
[download]

So, it looks like there are plenty of use cases ;)

perl -le'print map{pack c,($-++?1:13)+ord}split//,ESEL'

Comment on Re^5: RFC: "assignary" operator ?= : Download Code

Replies are listed 'Best First'.
Re^6: RFC: "assignary" operator ?= : by dave_the_m (Monsignor) on Dec 09, 2019 at 22:32 UTC
So, it looks like there are plenty of use cases Just the .pm files in the perl core distribution contain over 700,000 lines. You show that those, combined with a bunch of 3rd party modules, contain only around 100 instances of code likely to be able to make use of this proposed operator. If anything I think you've shown that this is a very rare use case and hardly justifies its addition to core. Dave.	[reply]
Re^7: RFC: "assignary" operator ?= : by LanX (Saint) on Dec 09, 2019 at 23:49 UTC
> you've shown that this is a very rare use case Plus many of these use cases are dubious and merit a new variable name for the sake of clarity. I'm a strong proponent of orthogonality, but I strongly doubt the costs of implementing this will ever pay off at this stage of language design. Cheers Rolf _{(addicted to the Perl Programming Language :) Wikisyntax for the Monastery FootballPerl is like chess, only without the dice}	[reply]
Re^7: RFC: "assignary" operator ?= : (rareness) by shmem (Chancellor) on Dec 10, 2019 at 11:19 UTC
Just the .pm files in the perl core distribution contain over 700,000 lines. You show that those, combined with a bunch of 3rd party modules, contain only around 100 instances of code likely to be able to make use of this proposed operator. To be exact, in that amount of code I've found 77 instances. And I have found 192 lines of code (two and a half times as much) which use the defined-or `//=`. If anything I think you've shown that this is a very rare use case and hardly justifies its addition to core. A bit more rare than the defined-or assignment operator `//=`, but anyways. Among 700.000 lines, 192 isn't that much either, so rareness of use cases isn't exactly a reason for an operator to be included or not. perl -le'print map{pack c,($-++?1:13)+ord}split//,ESEL'	[reply] [d/l] [select]
Re^8: RFC: "assignary" operator ?= : (rareness) by ikegami (Patriarch) on Dec 10, 2019 at 20:46 UTC
192 isn't that much either I'm not surprised, especially on CPAN. `\|\|` and `//` can often be used interchangeably, and `\|\|` is more backwards compatible.	[reply] [d/l] [select]
Re^8: RFC: "assignary" operator ?= : (rareness) by LanX (Saint) on Dec 10, 2019 at 11:58 UTC
> Among 700.000 lines, 192 isn't that much either, Backwards compatibility? Cheers Rolf _{(addicted to the Perl Programming Language :) Wikisyntax for the Monastery FootballPerl is like chess, only without the dice}	[reply]
Re^9: RFC: "assignary" operator ?= : (backward compatibility) by shmem (Chancellor) on Dec 10, 2019 at 13:18 UTC
Re^10: RFC: "assignary" operator ?= : (backward compatibility) by LanX (Saint) on Dec 10, 2019 at 13:38 UTC
Re^6: RFC: "assignary" operator ?= : (compatibility) by Anonymous Monk on Dec 09, 2019 at 01:53 UTC
So, it looks like there are plenty of use cases ;) Iff you dont need backwards compatibility	[reply]
Re^7: RFC: "assignary" operator ?= : (compatibility) by tobyink (Canon) on Dec 09, 2019 at 13:49 UTC
True. One of my modules is on that list, but I wouldn't use this operator because it needs to support Perl 5.6.1. toby d�t ink	[reply]