That's what I would expect, too, but if the order is undefined, we're not guaranteed to get what we expect.

For example, say that while a sub is running, it becomes apparent to Perl that the way it ordered things last time wasn't optimal (maybe the sub rarely uses its second argument, so evaluation of this argument should be deferred until it's actually used). Although unlikely, it would be legal to re-order anything whose order was undefined.

This is certainly bizarre behavior, and may well be a bug, but I've not seen mention of, or found, any solid documentation about whether the order of execution for these assignment and xor operators are defined or not, and if they are defined what the order is supposed to be.

---

---

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! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

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:
	&		&
	<		&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.