Beefy Boxes and Bandwidth Generously Provided by pair Networks
go ahead... be a heretic
 
PerlMonks  

Comment on

( #3333=superdoc: print w/ replies, xml ) Need Help??

That's not quite correct...

IO::Prompt returns an object, in that object bool is overloaded, and bool sets $_. (which is run for each iteration of the while to decided if it's a true or false value)

Which means that while ($z = prompt "") { will set $_ and $z. This is a bad idea. What if the code is used in an inner loop? when the outer loop uses $_ for example?

If one wants to get the same behaviour then it would be enough to do a simple assignment in the subroutine to $_ and return the value of $_.

Example code that is similar to the code in IO::Prompt

package Example; use overload q{bool} => sub { $_="def"; }; sub new { bless {}; } sub test { return $_[0]; } package main; my $z=new Example; $_="ghi"; while ($m = $z->test()) { print; print $m; last; };

Update: added relevant part of IO::Prompt


In reply to Re^2: sub that sets $_ by Animator
in thread sub that sets $_ by holli

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!
  • 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, 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, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • Outside of code tags, you may need to use entities for some characters:
            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.
  • Log In?
    Username:
    Password:

    What's my password?
    Create A New User
    Chatterbox?
    and the web crawler heard nothing...

    How do I use this? | Other CB clients
    Other Users?
    Others exploiting the Monastery: (6)
    As of 2014-08-01 06:36 GMT
    Sections?
    Information?
    Find Nodes?
    Leftovers?
      Voting Booth?

      My favorite superfluous repetitious redundant duplicative phrase is:









      Results (257 votes), past polls