I can confirm the same result on cygwin with 5.8.7:

 
% stephan@armen (/home/stephan) %
% perl -w sort_context.px
get_keys

called:array:13
called:array:13
called:array:13
called:array:13
[download]

deparse tells us:

% stephan@armen (/home/stephan) %
% perl -MO=Deparse sort_context.px
use warnings;
use strict 'refs';
my(%h) = (1, 2, 3, 4);
sub say {
    print @_, $/;
}
sub get_keys {
    print 'called:';
    if (wantarray) {
        print 'array:';
    }
    else {
        print defined wantarray ? 'scalar' : 'void';
    }
    return keys %h;
}
say sort('get_keys');
say((sort get_keys ()));
say sort(&get_keys);
say sort(&get_keys());
say sort(@{[get_keys()];});
say sort(@{[get_keys()];});
sort_context.px syntax OK
[download]

so in the first case get_keys gets interpreted as a string. seems like a bug (an old one...) with use strict; (especially if one follows the principle of least surprise) still it's true that it is quite ambiguous... hth --stephan

---

---

• Are you posting in the right place? Check out Where do I post X? to know for sure.
• Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:

  <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>

• Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
• Want more info? How to link or How to display code and escape characters are good places to start.