missing error in strict subs when the unary minus operator is applied on a bareword #17822
Comments
|
This is a feature: https://perldoc.pl/perlop#Symbolic-Unary-Operators |
|
(The reason |
This does not mention
No mention of the unary minus operator here, so that one should expect a compile-time error. |
|
This exception is deliberate, the parser explicitly turns off the flag ( This exception was introduced in it's current form in 7a52d87, before that the exception was done during tokenization. I've opened PR #17849 which documents this additional exception. |
|
Well, I don't see the point of this exception. It is surprising and can leave errors unnoticed. I wonder why anyone would use this "feature" in usual code. |
|
@vinc17fr it is used in quite a few very popular CPAN modules, like Moose and Tk. use Moose -meta_name => "my_meta";
my $txt = $main_window->Scrolled ("ROText" =>
-scrollbars => "e",
-wrap => "word",
-width => 70,
-height => 30,
-font => "{DejaVu Sans} 10",
-setgrid => 1,
-highlightthickness => 0,
-padx => 4,
-pady => 2,
-takefocus => 0,
)->grid (-sticky => "nsew");Removing this feature would break a lot of CPAN and make an aweful lot of users very very unhappy |
|
This won't affect such a code as barewords are already allowed before #!/usr/bin/env perl
use strict;
my %h = (foo => 0);
foo;accepts #!/usr/bin/env perl
use strict;
my %h = (-foo => 0);
-foo;should still accept |
|
It is also used throughout the Mojolicious ecosystem, Type::Tiny, App::Cmd, Gtk2, Data::Section, Smart::Comments, HTML::TreeBuilder, and these are just the things I found up to the letter C when looking for instances directly followed by a semicolon. It's not necessarily a good idea, because having a symbol defined before using it will parse as that symbol instead of a string unlike with the following fat comma, but it's not possible to change. |
Module:
Description
In strict subs, when the unary minus operator is applied on a bareword, perl does not issue any error.
Steps to Reproduce
perl -e 'use strict "subs"; my $x = -foo;'Expected behavior
One does not get any error, while one should have got an error just like with:
perl -e 'use strict "subs"; my $x = foo;'and
perl -e 'use strict "subs"; my $x = -foo**2;'Perl configuration
The text was updated successfully, but these errors were encountered: