# Re: Strong encapsulation, weak encapsulation, and getSearchTree

From: Wolfgang Lux <wlux_at_uni-muenster.de>
Date: Tue, 15 Jun 2004 09:54:34 +0200

> Right, but in
>
> let x = coin
> y = clone x
> in ...
>
> how do you ensure that x is not evaluated before invoking clone?
> For example, if ... is x+y, do you evaluate first x or y? The
> semantics should be independent of the evaluation order of the
> arguments of +. Indeed we are working on evaluating x and y in
> parallel, otherwise it is very easy to lose completeness in the
> presence of residuation.

Sorry for being so cryptic and terse in my previous mail. The ...
part in the let expression was (this time without infix notation):

seq y (x + y)

The seq function, which I once suggested to carry over from Haskell,
has the semantics
seq \bot _ = \bot
seq x y = y if x /= \bot
Thus, it must evaluate its first argument before the second.

I hope this makes things clear now.

Wolfgang

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Received on Tue Jun 15 2004 - 12:12:53 CEST

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