mirror/perl
1
0
Fork 0
mirror of https://github.com/Perl/perl5.git synced 2026-01-26 08:38:23 +00:00
Code Issues Packages Projects Releases Wiki Activity

Make postfix dereferencing work without the postderef feature

Browse Source 
The feature still exists, for compatibility with code that tries to enable
it, but it has no effect. The postderef_qq feature still exists, however.
This commit is contained in:
Aaron Crane 2015-07-13 12:58:51 +01:00
parent 4134928828
commit 1c2511e0ac
8 changed files with 52 additions and 66 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
feature.h
View File

@ -78,9 +78,8 @@
#define FEATURE_POSTDEREF_IS_ENABLED \
( \
CURRENT_FEATURE_BUNDLE == FEATURE_BUNDLE_523 \
|| (CURRENT_FEATURE_BUNDLE == FEATURE_BUNDLE_CUSTOM && \
FEATURE_IS_ENABLED("postderef")) \
CURRENT_FEATURE_BUNDLE == FEATURE_BUNDLE_CUSTOM && \
FEATURE_IS_ENABLED("postderef") \
)
#define FEATURE_ARYBASE_IS_ENABLED \

31
lib/feature.pm
View File

@ -29,7 +29,7 @@ our %feature_bundle = (
"5.10" => [qw(array_base say state switch)],
"5.11" => [qw(array_base say state switch unicode_strings)],
"5.15" => [qw(current_sub evalbytes fc say state switch unicode_eval unicode_strings)],
"5.23" => [qw(current_sub evalbytes fc postderef postderef_qq say state switch unicode_eval unicode_strings)],
"5.23" => [qw(current_sub evalbytes fc postderef_qq say state switch unicode_eval unicode_strings)],
"all" => [qw(array_base bitwise current_sub evalbytes fc lexical_subs postderef postderef_qq refaliasing say signatures state switch unicode_eval unicode_strings)],
"default" => [qw(array_base)],
);
@ -260,26 +260,31 @@ This feature is available from Perl 5.18 onwards.
=head2 The 'postderef' and 'postderef_qq' features
The 'postderef' feature allows the use of L<postfix dereference
syntax|perlref/Postfix Dereference Syntax>. For example, it will make the
following two statements equivalent:
The 'postderef_qq' feature extends the applicability of L<postfix
dereference syntax|perlref/Postfix Dereference Syntax> so that postfix array
and scalar dereference are available in double-quotish interpolations. For
example, it makes the following two statements equivalent:
my @x = @{ $h->{a} };
my @x = $h->{a}->@*;
my $s = "[@{ $h->{a} }]";
my $s = "[$h->{a}->@*]";
The 'postderef_qq' feature extends this, for array and scalar dereference, to
working inside of double-quotish interpolations.
These features are available from Perl 5.20 onwards. In Perl 5.20 and 5.22,
they were classed as experimental, and Perl emitted a warning for their
This feature is available from Perl 5.20 onwards. In Perl 5.20 and 5.22, it
was classed as experimental, and Perl emitted a warning for its
usage, except when explicitly disabled:
no warnings "experimental::postderef";
As of Perl 5.24, use of these features no longer triggers a warning, though
As of Perl 5.24, use of this feature no longer triggers a warning, though
the C<experimental::postderef> warning category still exists (for
compatibility with code that disables it).
The 'postderef' feature was used in Perl 5.20 and Perl 5.22 to enable
postfix dereference syntax outside double-quotish interpolations. In those
versions, using it triggered the C<experimental::postderef> warning in the
same way as the 'postderef_qq' feature did. As of Perl 5.24, this syntax is
not only no longer experimental, but it is enabled for all Perl code,
regardless of what feature declarations are in scope.
=head2 The 'signatures' feature
B<WARNING>: This feature is still experimental and the implementation may
@ -375,7 +380,7 @@ The following feature bundles are available:
:5.24 say state switch unicode_strings
unicode_eval evalbytes current_sub fc
postderef postderef_qq
postderef_qq
The C<:default> bundle represents the feature set that is enabled before
any C<use feature> or C<no feature> declaration.

9
pod/perldelta.pod
View File

@ -52,9 +52,12 @@ you could use the C<bigint> pragma.
=head2 Postfix dereferencing is no longer experimental
Using the C<postderef> and C<postderef_qq> features no longer emits a warning.
Existing code that disables that warning category will continue to work. The
C<5.24> feature bundle now includes those features.
Using the C<postderef> and C<postderef_qq> features no longer emits a
warning. Existing code that disables the C<experimental::postderef> warning
category that they previously used will continue to work. The C<postderef>
feature has no effect; all Perl code can use postfix dereferencing,
regardless of what feature declarations are in scope. The C<5.24> feature
bundle now includes the C<postderef_qq> feature.
=head1 Security

8
pod/perlref.pod
View File

@ -758,7 +758,9 @@ For example:
$r = [ 1, [ 2, 3 ], 4 ];
$r->[1]->@*; # equivalent to @{ $r->[1] }
This syntax must be enabled with C<use feature 'postderef'>.
In Perl 5.20 and 5.22, this syntax must be enabled with C<use feature
'postderef'>. As of Perl 5.24, no feature declarations are required to make
it available.
Postfix dereference should work in all circumstances where block
(circumfix) dereference worked, and should be entirely equivalent. This
@ -781,7 +783,7 @@ Glob elements can be extracted through the postfix dereferencing feature:
Postfix array and scalar dereferencing I<can> be used in interpolating
strings (double quotes or the C<qq> operator), but only if the
additional C<postderef_qq> feature is enabled.
C<postderef_qq> feature is enabled.
=head2 Postfix Reference Slicing
@ -800,7 +802,7 @@ Slices">, also behaves as expected:
As with postfix array, postfix value slice dereferencing I<can> be used
in interpolating strings (double quotes or the C<qq> operator), but only
if the additional C<postderef_qq> L<feature> is enabled.
if the C<postderef_qq> L<feature> is enabled.
=head1 Assigning to References

29
regen/feature.pl
View File

@ -60,7 +60,7 @@ my %feature_bundle = (
"5.21" => [qw(say state switch unicode_strings unicode_eval
evalbytes current_sub fc)],
"5.23" => [qw(say state switch unicode_strings unicode_eval
evalbytes current_sub fc postderef postderef_qq)],
evalbytes current_sub fc postderef_qq)],
);
# not actually used currently
@ -575,26 +575,31 @@ This feature is available from Perl 5.18 onwards.
=head2 The 'postderef' and 'postderef_qq' features
The 'postderef' feature allows the use of L<postfix dereference
syntax|perlref/Postfix Dereference Syntax>. For example, it will make the
following two statements equivalent:
The 'postderef_qq' feature extends the applicability of L<postfix
dereference syntax|perlref/Postfix Dereference Syntax> so that postfix array
and scalar dereference are available in double-quotish interpolations. For
example, it makes the following two statements equivalent:
my @x = @{ $h->{a} };
my @x = $h->{a}->@*;
my $s = "[@{ $h->{a} }]";
my $s = "[$h->{a}->@*]";
The 'postderef_qq' feature extends this, for array and scalar dereference, to
working inside of double-quotish interpolations.
These features are available from Perl 5.20 onwards. In Perl 5.20 and 5.22,
they were classed as experimental, and Perl emitted a warning for their
This feature is available from Perl 5.20 onwards. In Perl 5.20 and 5.22, it
was classed as experimental, and Perl emitted a warning for its
usage, except when explicitly disabled:
no warnings "experimental::postderef";
As of Perl 5.24, use of these features no longer triggers a warning, though
As of Perl 5.24, use of this feature no longer triggers a warning, though
the C<experimental::postderef> warning category still exists (for
compatibility with code that disables it).
The 'postderef' feature was used in Perl 5.20 and Perl 5.22 to enable
postfix dereference syntax outside double-quotish interpolations. In those
versions, using it triggered the C<experimental::postderef> warning in the
same way as the 'postderef_qq' feature did. As of Perl 5.24, this syntax is
not only no longer experimental, but it is enabled for all Perl code,
regardless of what feature declarations are in scope.
=head2 The 'signatures' feature
B<WARNING>: This feature is still experimental and the implementation may

3
t/lib/warnings/toke
View File

@ -1040,10 +1040,9 @@ EXPECT
Useless use of \E at - line 3.
########
# toke.c
use feature 'postderef', 'postderef_qq';
use feature 'postderef_qq';
(\$_)->$*;
"$_->$*";
no warnings 'experimental::postderef';
(\$_)->$*;
"$_->$*";
EXPECT

28
t/op/postfixderef.t
View File

@ -16,33 +16,7 @@ BEGIN {
use strict qw(refs subs);
plan(125);
{
no warnings qw 'deprecated syntax';
eval '[]->$*';
like $@, qr/Can't call method/, '->$* outside of feature scope';
eval '[]->@*';
like $@, qr/syntax error/, '->@* outside of feature scope';
eval '[]->@[1]';
like $@, qr/syntax error/, '->@[ outside of feature scope';
eval '[]->@{1}';
like $@, qr/syntax error/, '->@{ outside of feature scope';
eval '[]->%*';
like $@, qr/syntax error/, '->%* outside of feature scope';
eval '[]->%[1]';
like $@, qr/syntax error/, '->%[ outside of feature scope';
eval '[]->%{1}';
like $@, qr/syntax error/, '->%{ outside of feature scope';
eval '[]->&*';
like $@, qr/syntax error/, '->&* outside of feature scope';
eval '[]->**';
like $@, qr/syntax error/, '->** outside of feature scope';
eval '[]->*{';
like $@, qr/syntax error/, '->*{ outside of feature scope';
}
use feature 'postderef';
plan(115);
{
no strict 'refs';

5
toke.c
View File

@ -5133,12 +5133,11 @@ Perl_yylex(pTHX)
else if (*s == '>') {
s++;
s = skipspace(s);
if (FEATURE_POSTDEREF_IS_ENABLED && (
((*s == '$' || *s == '&') && s[1] == '*')
if (((*s == '$' || *s == '&') && s[1] == '*')
||(*s == '$' && s[1] == '#' && s[2] == '*')
||((*s == '@' || *s == '%') && strchr("*[{", s[1]))
||(*s == '*' && (s[1] == '*' || s[1] == '{'))
))
)
{
PL_expect = XPOSTDEREF;
TOKEN(ARROW);