I'm undecided on the issue. Consider the code I've seen on PerlMonks this week: 

$field = $sth->fetchrow_array();

[download]

The result of fetchrow_array in scalar context is undefined or at least undocumenteddocumented as undefined, at least some of the time. What should fetch_array do in this situation? Let the result be undefined (GIGO), or provide something sensible? The latter requires wantarray (or at least a commitment to using a compatible op).

Given a "$scalar = x()", I expect that x() returns a scalar. I know very well that's not necessarily true

It is necessarily true. x() cannot return anything but a scalar in scalar context.

In scalar context
sub x { ...; @x }@x evaluates to the num of elements in @x, so
x() returns the num of elements in @x
sub x { ...; ($x,$y) }($x,$y) evaluates to $y, so
x() returns $y
sub x { ...; () }() evaluates to undef, so
x() returns undef

In reply to Re: Use of wantarray Considered Harmful by ikegami
in thread Use of wantarray Considered Harmful by kyle

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.