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Re: Obsolete text in

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December 28, 2015 17:22
Re: Obsolete text in
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On 28 December 2015 at 17:47, Father Chrysostomos <> wrote:
> John Imrie wrote:
>> On 28/12/2015 01:01, Father Chrysostomos wrote:
>> > But that is exactly how symbols are exported (assuming you mean *
>> > rather than *). Normalization for hash access (which is how we would
>> > have to do this), even if it is limited to stashes, would be an effic-
>> > iency nightmare.
>> I was
>> hoping that we could do the normalisation on insert into the stash. So
>> that the stash it's self was normalised. This would make it a compile
>> time operation, or one hit for each symbol you are exporting. I don't
>> know enough of the Perl internals as to why this would have to be on
>> access rather than insert.
> If the string "whatever" used to ask for the symbol, as in
>     use Foo "whatever";
> is not normalised, but *Foo::whatever is stored in the *Foo:: stash
> normalised, then the symbol lookup that happens at run time every time
> the symbol is exported will at some point have to normalise the name
> provided by the caller.

Just FYI, This already happens for utf8 keys in hashes.

During fetch or store any utf8 key will trigger a downgrade attempt.

During store, if the downgrade is successful then the key will be
marked as "was-utf8", so that later when it is fetched it will be
upgraded. If it is not successful then the key will be looked up by
its utf8 byte sequence.

Combining characters of course are not "properly" downgraded.

Anyway, the consequence of this is that unicode hash lookups are much
slower than they could be.


perl -Mre=debug -e "/just|another|perl|hacker/"

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