Path: utzoo!utgpu!attcan!uunet!lll-winken!ames!mailrus!ukma!david
From: david@ms.uky.edu (David Herron -- One of the vertebrae)
Newsgroups: comp.lang.pascal
Subject: Re: Enumerated types in TP40
Keywords: none
Message-ID: <10838@s.ms.uky.edu>
Date: 7 Jan 89 03:05:14 GMT
References: <363@lafcol.UUCP>
Reply-To: agollum@engr.uky.edu
Distribution: na
Organization: U of Kentucky, Mathematical Sciences
Lines: 49

In article <363@lafcol.UUCP> pilgrimk@lafcol.UUCP (Guru Jee) writes:
>How can the number of elements in an enumerated type be determined?
>
> e.g. type
>          Enum1 = (One, Two, Three, Four);
>          Enum2 = (_One, _Two, _Three);

If you must do this at runtime, then something like 

var
    DummyArr = array[Enum1] of byte

...

HowManyEnums = sizeof(DummyArr);

ought to work.  Another method which requires some attention if you change
the declaration of Enum1 would be:

const
     Enum1Max:Enum1 = Four;

...

HowManyEnums = ord(Enum1Max) + 1;

The best solution would be simply to define a constant with the value
you want:

const
     HowManyEnums = 4;

TP 5.0 allows expressions to define constants so something like

const
     Enum1Max:Enum1 = Four;
     HowManyEnums:byte = succ(ord(Enum1Max));

Would also work (though this solution and its runtime counterpart above
depend on how TP implements enumerated types, and may break in the future).
There may be an even better solution available under 5.0 (I don't have
it, myself).

Kenneth Herron
-- 
<-- David Herron; an MMDF guy                              <david@ms.uky.edu>
<-- ska: David le casse\*'      {rutgers,uunet}!ukma!david, david@UKMA.BITNET
<-- Now I know how Zonker felt when he graduated ...
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