Beefy Boxes and Bandwidth Generously Provided by pair Networks
"be consistent"

Comment on

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

Curiously, both Ruby and PHP, both with the same relative precedence as Perl for the ternary and assignment operators, bend the rules differently. For example, this Ruby program:

config = '' fred = 42 fred == 42 ? config = 'k1' : config = 'k2' print "config=#{config}\n"
and PHP program:
<?php $config = ''; $fred = 42; $fred == 42 ? $config = 'k1' : $config = 'k2'; echo "config=$config\n"; ?>
both run without error, but, unlike Perl (which produces config=k2), both Ruby and PHP produce config=k1.

Arguably, all three languages should produce a syntax error.

Update: gcc produces a syntax error "f.c:6: error: lvalue required as left operand of assignment" with this test program (further update: g++ compiles it happily though and with the same semantics as the Ruby and PHP test programs):

#include <stdio.h> int main() { int config = 0; int fred = 42; fred == 42 ? config = 1 : config = 2; printf("config=%d\n", config); return 0; }
Adding parentheses to line 6:
fred == 42 ? (config = 1) : (config = 2); // this works fred == 42 ? config = 1 : (config = 2); // also works fred == 42 ? (config = 1) : config = 2; // syntax error
makes it work the same as the Ruby and PHP test programs.

In reply to Re^2: Surprised by Perl parse of ternary operator by eyepopslikeamosquito
in thread Surprised by Perl parse of ternary operator by eyepopslikeamosquito

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, 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
  • 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.
  • Log In?

    What's my password?
    Create A New User
    [erix]: ( you use anchors to jump to via a #-suffix to the url -- I am sure you know )
    [choroba]: ah, these

    How do I use this? | Other CB clients
    Other Users?
    Others examining the Monastery: (5)
    As of 2018-06-19 12:43 GMT
    Find Nodes?
      Voting Booth?
      Should cpanminus be part of the standard Perl release?

      Results (114 votes). Check out past polls.