which to me looks like: $OPER = 's' = 'c'; when $test ne 'c' is true. And that should fail with a "Can't modify constant item in scalar assignment" error.

You're forgetting the precedence -- or should I say associativity? -- no, I think precedence is correct here. It is actually like ($OPER = 's') = 'c', which, while admittedly bizarre, is perfectly legal, since $OPER = 's' evaluates to an lvalue $OPER. Observe the difference: 

sidhekin@blackbox:~$ perl -le '($c = 1) = 2; print $c'
2
sidhekin@blackbox:~$ perl -le '$c = 1 = 2; print $c'
Can't modify constant item in scalar assignment at -e line 1, near "2;
+"
Execution of -e aborted due to compilation errors.
sidhekin@blackbox:~$

[download]

print "Just another Perl ${\(trickster and hacker)},"
The Sidhekin proves Sidhe did it!

In reply to Re^4: ternary operator by Sidhekin
in thread ternary operator by pglenski

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.