Re^2: Does Perl do constant anonymous hash creation optimisation?

Thanks for that - have never really used

  use constant {...};
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we usually do this at the top of the package

 our $SKIPWORDS = {};
[download]

so I wonder if there is an overhead for use constant?

The thing I like about the inline/anon hashes is that all the logic and data is clearly seen in one place.

In this specific example, the package is 5000+ lines long, and the words() function because it starts with w... will end up near the end of the file - 5000 lines away from the skip and substitute words.

Will probably go with the use contant if there is no overhead - this func will get called a lot in an inner loop with anywhere up to a million times per run.

Thanks again, for the pointers,

Jeff

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Re^3: Does Perl do constant anonymous hash creation optimisation? by BrowserUk (Patriarch) on Jul 08, 2006 at 15:53 UTC
Using constant is 3 times faster than your inline construct. Read more... (3 kB) In this specific example, the package is 5000+ lines long, and the words() function because it starts with w... will end up near the end of the file - 5000 lines away from the skip and substitute words. With that much data, I'd definitely be putting it in a separate file on it's own. If you do not want to go to the bother of wrapping it up as a module, you could just put the constant hash definition into a file of it's own and use the simple `do 'wordshash.pl';` just before the associated `words()` functions, though it would probably be better to wrap the function and data into a module and do something like `use My::Words qw[ words ];` in the main code. Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. Lingua non convalesco, consenesco et abolesco. -- Rule 1 has a caveat! -- Who broke the cabal? "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice.	[reply] [d/l] [select]
Re^4: Does Perl do constant anonymous hash creation optimisation? by jaa (Friar) on Jul 08, 2006 at 17:34 UTC
Fab! Thanks very much! I am going to keep this to remind me how to performance test my funcs better in the future. Regards, Jeff	[reply]
Re^3: Does Perl do constant anonymous hash creation optimisation? by jaa (Friar) on Jul 10, 2006 at 15:06 UTC
Dear Monks, Extending the cmpthese() example, I found no appreciable performance difference between: `use constant SKIPWORDS => {...}; our $SKIPWORDS = {};` [download] So a big thumbs up for use constant()! Thanks for the help! Jeff	[reply] [d/l]