Erlang hints for an OO junkie

Matthias Lang <>
Tue Aug 10 21:33:10 CEST 2004


Vlad Balin writes:

 > There's an another problem. Erlang is functional language, where destructive
 > updates and other side effects are not desirable things.

 > If you will use processes as a unit of incapsulation (think of it as object)
 > you> will introduce destructive updates, and loose the benefits of Erlang as
 > functional language.
[...]
 > If you going to use it your design as a leading principle, the better idea
 > would be to use Smalltalk instead, not to emulate it in Erlang.

Desperately avoiding side effects feels a bit like trying to write
Haskell programs in Erlang. I don't know if that's better or worse
than trying to write Smalltalk programs in Erlang, but it'll also lead
to disappointment, especially when implementing a system with a lot of
inherent concurrency (e.g. a switch).

Using a process for encapsulation _is_ a common, normal and useful
thing to do in Erlang. I'm not advocating transforming an OO design
into an Erlang implementation by replacing all objects with a process,
but often a process _is_ a useful unit of encapsulation.

Matthias



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