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From: dmitry@elros.cbb-automation.de (Dmitry A. Kazakov)
Newsgroups: comp.lang.ada
Subject: Re: Side-Effects in Functions [Rosen Trick]
Date: Mon, 05 Nov 2001 10:29:50 GMT
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On 4 Nov 2001 23:26:03 -0800, pete@nospam <pete_member@newsguy.com>
wrote:

>functions, in the mathemtical sense, do not accept an IN OUT paramters,
>and do not have side effects.
>
>y=f(x), x here can never be modified by the function f().
>
>so, Ada function is more like a math function.

No function in a programming language may have no side effects. One
could say that there are side effects which are of no interest, but no
more than that.

The discussion about in out parameters is proved to be evergreen
(:-)). But what I presonally cannot understand is why not to allow
PROCEDUREs having a result, i.e.

procedure Find (Folder : in out Table) return Table_Token;

procedure GetNext  (Item_List : in out Iterator) return Element;

etc.

Regards,
Dmitry Kazakov