tye provided the answer in CB
<tye> as to /why/ that distinction matters: it is a parser restriction (and parsing sort arguments is rather buggy anyway)
<tye> perl -MO=Deparse -e "sort foo(), <>" says "sort foo (), <ARGV>;", which leads me to think that the space is important there
Investigated further and this is what I found:
 perl -MO=Deparse -e 'sub a {}; my $r = \&a; sort $r (1,2)'           
+                                                
 sub a {

}
my $r = \&a;
sort $r 1, 2;

[download]
perl -MO=Deparse -e 'sub a {}; sort \&a (1,2)'
sub a {

}
sort \(&a(1, 2));

[download]

In reply to Re: Is it possible to sort using a coderef, without first storing the coderef in a scalar by imp
in thread Is it possible to sort using a coderef, without first storing the coderef in a scalar by imp

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.