RE: Named Integers

From: Fyodor Tkachov <"Fyodor>
Date: Mon, 29 Nov 2004 15:05:33 +0300

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Chris already mentioned a useful trick with read-only variables.

I just mention that if one introduces record types for those, one could ensure a better control over incorrect assignments (especially with LIMITED records).

If adding a syntactic sugar of this kind were deemed necessary, I would opt for implementing this via LIMITED records -- with a complete ban on doubtful assignments etc.:

        TYPE Option = POINTER TO LIMITED RECORD END;
        VAR opt0-, opt1-, opt2-: Option;

And leave things as is for situations like Color where arithmetic (mixing) is allowed. Although this can also be done via LIMITED records with internal fields.

A bit cumbersome, but everything is explicit, and I personally do not feel the extra typing to be too much of a concern that enumerated types should be explicitly introduced.

Cheers
Fyodor

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Received on Mon Nov 29 2004 - 13:05:33 UTC