[erlang-questions] 回复： which one is more efficiency? ets or pattern match?

[Jesper Louis Andersen]

It is pretty good for lookup tables. Another such implementation:

https://github.com/jlouis/eministat/blob/master/src/eministat_analysis.erl#L85-L190

On Wed, Mar 16, 2016 at 1:16 PM, Dan Gudmundsson <dangud@REDACTED> wrote:

> You can build large tuples and use element/2 on them as well, for example
> see functions in the bottom of rand.erl.
>
> On Wed, Mar 16, 2016 at 12:58 PM Vance Shipley <vances@REDACTED> wrote:
>
>> On Wed, Mar 16, 2016 at 5:07 PM, 饕餮 <249505968@REDACTED> wrote:
>> > But someone is afraid about the efficiency of pattern match.(because we
>> are
>> > not very sure about the efficiency of pattern match,just heard that if
>> the
>> > code is good, it will be a binary search).
>>
>> Pattern matching is quite efficient up to some point of design intent.
>> Some guidance is in the Efficiency Guide here:
>> http://erlang.org/doc/efficiency_guide/functions.html#id68205
>>
>> What you need to worry about however is in how many clauses heads you
>> have.  I once benchmarked this and found that it worked well up to
>> something on the order of thousands but wouldn't compile beyond that.
>> This is the sort of thing which could change for the better or worse
>> with any Erlang release because they've never expressed a guarantee.
>> I haven't tried it lately.
>>
>>
>>
>> --
>>      -Vance
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-- 
J.
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