[erlang-questions] Efficiency is passing a functin
Sun Sep 23 23:56:32 CEST 2012
On 23/09/2012, at 12:07 PM, James Rosenblum wrote:
> Is there an appreciable difference in these two ways of passing a function?
> F = fun(A,B) -> my_function(A,B) end.
> lists:map(F, Lst)
> lists:map(fun my_function/2, Lst)
The two are not precisely semantically equivalent.
- The second one exposes a function to external use;
you should generally expose nothing that you don't mean to retain.
+ The second one will work nicely if you hot-reload the module.
But there are two questions I have to ask:
(1) Why not write [my_function(X) || X <- Lst]
and get a direct local call to my_function without exporting
(2) Why not *measure* the three versions and see whether the
difference is of any practical significance in the context
of everything else going on in the real program?
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