Re^4: Why doesn't Perl provide %_ as the hash equivalent of @

Replies are listed 'Best First'.
Re^5: Why doesn't Perl provide %_ as the hash equivalent of @_ in subs? (ugly++) by hdb (Monsignor) on Sep 27, 2013 at 10:29 UTC
Like with $&, $`, $' you would only have a performance hit if you actually used it.	[reply] [d/l]
Re^6: Why doesn't Perl provide %_ as the hash equivalent of @_ in subs? (ugly++) by tobyink (Canon) on Sep 28, 2013 at 07:13 UTC
In recent versions of Perl there's virtually no performance hit using these variables any more. `use Moops; class Cow :rw { has name => (default => 'Ermintrude') }; say Cow->new->name`	[reply]
Re^5: Why doesn't Perl provide %_ as the hash equivalent of @_ in subs? (ugly++) by BrowserUk (Patriarch) on Sep 27, 2013 at 10:53 UTC
If it would make all function calls slower, then I agree with you that it wouldn't be worth it. 3 times slower... `sub withNames{ local %_ = @_; ++$_{$_} for keys %_; };; sub sansNames{ ++$_ for @_; };; cmpthese -1,{a=>q[ withNames( 1 .. $_2 ) for 1..5 ], b=>q[ sansNames( + 1..$_ ) for 1 .. 5 ] };; Rate a b a 32135/s -- -75% b 127549/s 297% --` [download] hash could be built when first used... Would that not be technically feasible?* Feasible, yes. A good idea? Sounds like a recipe for disaster to me. And all to save you adding `local %_ = @_;` where you want it. Worth the effort? Absolutely not. With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice.	[reply] [d/l] [select]
Re^6: Why doesn't Perl provide %_ as the hash equivalent of @_ in subs? (ugly++) by Anonymous Monk on Sep 28, 2013 at 06:12 UTC
sub withNames{ local %_ = @_; ++$_{$_} for keys %_; };; Try `++$_ for values %_;` :P lol Yeah, local %_=@_; is not hard to type :)	[reply] [d/l]
Re^7: Why doesn't Perl provide %_ as the hash equivalent of @_ in subs? (ugly++) by BrowserUk (Patriarch) on Sep 28, 2013 at 07:02 UTC
Try `++$_ for values %_;` That improves things: `sub sansNames{ ++$_ for @_; };; sub withNames{ local %_ = @_; ++$_ for values %_; };; cmpthese -1,{ a=>q[ withNames( 1 .. $_*2 ) for 1..5 ], b=>q[ sansNames( 1..$_ ) for 1 .. 5 ] };; Rate a b a 35072/s -- -71% b 122333/s 249% --` [download] Though ... a benchmark of named parameters that doesn't use the names to access the parameters ... :) With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice.	[reply] [d/l] [select]


No such thing as a small change
	PerlMonks

Re^4: Why doesn't Perl provide %_ as the hash equivalent of @_ in subs? (ugly++)