[erlang-questions] Idiom for multiple case matches

[Christian]

And here is the release notes from R12B-0:

>    OTP-6850  Literal lists, tuples, and binaries are no longer constructed
>	      at run-time as they used to be, but are stored in a
>	      per-module constant pool. Literals that are used more than
>	      once are stored only once.
>
>	      This is not a change to the language, only in the details of
>	      its implementation. Therefore, the implications of this
>	      change is described in the Efficiency Guide.

2008/11/7 Edwin Fine <erlang-questions_efine@REDACTED>:
> Ulf,
>
> Isn't there also more garbage (as in GC) created by Mats' solution? Doesn't
> the list "aeiouy" get created and destroyed every time, or does the compiler
> "know" it is constant and make one constant copy of it that is not GC'ed?
>
> Regards,
> Edwin Fine
>
> On Fri, Nov 7, 2008 at 11:52 AM, Ulf Wiger <ulf@REDACTED> wrote:
>>
>> It's slower, true, but both are fairly fast*, and the lists:member/2
>> solution is also very concise.
>>
>> * I ran a small benchmark. On the given machine, Robert's
>> solution took ca 0.05 usec/call, while Mats's solution took
>> ca 0.09 usec/call (on average, iterating 1000 over the set of
>> vowels "aeiouyAEIOUY"). Using the smaller set "aeiouy",
>> Robert's code still took 0.05 usec/call, while Mats's code
>> used 0.08 usec.
>>
>> BR,
>> Ulf W
>>
>> 2008/11/7 Hynek Vychodil <vychodil.hynek@REDACTED>:
>> >
>> >
>> > On Fri, Nov 7, 2008 at 3:22 PM, mats cronqvist <masse@REDACTED>
>> > wrote:
>> >>
>> >> "Robert Virding" <rvirding@REDACTED> writes:
>> >>
>> >> > A reasonable way of doing it would be:
>> >> >
>> >> > case is_vowel(Char) of
>> >> >     true -> ... ;
>> >> >     false -> ...
>> >> > end
>> >>
>> >>
>> >> is_wovel(C) -> lists:member(C,"aeiouy").
>> >
>> > It is slower than Robert's solution. If performance is significant
>> > lists:member solution is worse.
>> >>
>> >>
>> >>  mats
>> >> _______________________________________________
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>> >> http://www.erlang.org/mailman/listinfo/erlang-questions
>> >
>> >
>> >
>> > --
>> > --Hynek (Pichi) Vychodil
>> >
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