What happened to dor and err in Perl 5.10?

tomfahle has asked for the wisdom of the Perl Monks concerning the following question:

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Re: What happened to dor and err in Perl 5.10? by hipowls (Curate) on Jan 05, 2008 at 10:33 UTC
`use feature 'dor'` was an alias for `use feature 'err'`, there wasn't a dor keyword. There is a longish thread at http://www.nntp.perl.org/group/perl.perl5.porters/2007/09/msg128170.html which discusses the reason for removing the err keyword. It boils down to people associating err with errors and therefore too likely to clash with current practice and confuse those new to the operator. The // operator remains and since it doesn't clash syntactically with the earlier use of // (one is an operator the other a term) there is no need for `use feature 'err'`. Update: as pointed out by ysth below I'd missed the significance of http://www.nntp.perl.org/group/perl.perl5.porters/2007/09/msg128324.html where Rafael Garcia-Suarez writes "Larry decided to rename err to orelse in Perl 6.". Thanks to ysth for pointing it out.	[reply] [d/l] [select]
Re^2: What happened to dor and err in Perl 5.10? by ysth (Canon) on Jan 06, 2008 at 02:10 UTC
It boils down to people associating err with errors and therefore too likely to clash with current practice and confuse those new to the operator. No, that's not what it boils down to. That thread contains that (and other) complaints, but the real killer was that perl6 won't have an err; it will have an orelse operator instead, that apparently will be functionally different from a low-precedence //. -- CollegeGear.com - more than just college gear (though, yes, we have college-branded teddy bears)	[reply]
Re^3: What happened to dor and err in Perl 5.10? by hipowls (Curate) on Jan 06, 2008 at 03:03 UTC
You are right, it was longish thread and I missed the significance of http://www.nntp.perl.org/group/perl.perl5.porters/2007/09/msg128324.html. Thanks for pointing it out;)	[reply]
Re^2: What happened to dor and err in Perl 5.10? by tomfahle (Priest) on Jan 05, 2008 at 13:05 UTC
Thank you. That's exactly what I am looking for.	[reply]
Re^3: What happened to dor and err in Perl 5.10? by ikegami (Patriarch) on Jan 05, 2008 at 14:44 UTC
Just like `or` is almost only be useful in structures of the form `func arg or stmt;` [download] `err` would almost only be useful in structures of the form `func arg err stmt;` [download] Simply replacing `err` with `//` would be wrong, but appropriate use of parens will do the trick: `func(arg) // stmt;` [download] `(func arg) // stmt;` [download] `if (not defined func arg) { stmt; }` [download] etc.	[reply] [d/l] [select]