Re: Execution time of class versus record

[Sam Steingold <sds@gnu.org>]

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tmp123@menta.net wrote:
> Hello,
> 
> I've tried to implement two equivalent small programs, the one using
> class, the other one using records. The resulting execution times says
> that class are 7-8 times slower than record (compiled with ocamlopt in a
> Intel machine).

As other have explained, classes use hash table lookup per slot access,
while records access fields by offsets computed at compile-time.

> Please, knows someone what I'm doing wrong?
>  let t0 = Unix.gettimeofday () in
>  Printf.printf "elapsed = %f\n" (Unix.gettimeofday() -. t0)

Unix.gettimeofday is "wall clock".
Unix.times is "CPU time".
use the latter to time your programs because the former depends on the
machine load at the time of the test while the latter does not.

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