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Re: Why OCaml sucks
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Date: 2008-05-09 (18:17)
From: Ulf Wiger (TN/EAB) <ulf.wiger@e...>
Subject: Re: [Caml-list] Re: Why OCaml sucks
Jon Harrop skrev:
> On Friday 09 May 2008 14:00:52 you wrote:
>> Jon Harrop skrev:
>>> . Parallelism is for performance and performance
>>  >   requires mutable data structures.
>> I disagree. SMP Erlang has no mutable data structures,
>> but achieves very good scalability anyway.
> Scalability != performance. For CPU intensive tasks, 
 > Erlang is uniformly slow.

I don't see how you can say that. If you introduce the
restriction that there can be only one CPU, then this
might be true. Some applications are very difficult to
scale to multiple CPUs, but others are inherently
scalable. For some problems, mutable data structures
make all the difference, and in others, they just make
a mess of things.

If you say "parallelism is for performance", you imply
that the program is scalable, and that it actually makes
a difference to add more CPUs. In this case, mutable
the presence of data structures will make scaling more
difficult. Most problems involved in utilizing multicore
boil down to the widespread use of mutable data structures.

If the problem isn't scalable, then other tricks are needed
to achieve performance, and mutable data structures may
be indispensable.

Ulf W