[erlang-questions] Re: Best way to implement a simple cache

[David Mercer]

Matt Stancliff wrote:

> While I have my benchmarking hat on, let's check function calls too:
> Call Method             ||  Multiplier  || Percent Slowdown || Calls
> Per Second
> =
> =
> =
> =
> =
> =
> =
> ========================================================================
> apply(?MODULE, foo, [])        1.00x            0%
> 96,089,747.8
> ?MODULE:foo()                  1.01x            1%
> 94,809,477.4
> foo()                          1.09x            9%
> 88,485,052.9
> fun() -> ok end()              3.15x          215%
> 30,489,431.6
> apply(foo, [])                 3.50x          250%
> 27,481,044.5
> Module:Fun()                   5.22x          422%
> 18,392,358.4

Is this a surprise to anyone else?  I myself would have expected foo() to be
the fastest, since it knows exactly which function to call, whereas the two
that rank above it have to look for the most recent version of foo/0.
Anyone have an explanation for this?