----boundary-LibPST-iamunique-43315283_-_-
Content-type: text/plain
Hi Wojtek,
afaik, this is not (yet) a FAQ.
I guess that leaving out unsigned arithmetic was a deliberate
decision, although I also sometimes miss them.
The times of necessity to use variables, which are as small
as possible, seems to have vanished (except for embedded
systems).
Let me ask: Do you really need the aritmetic on BYTE ?
If you do not need it, this might be a solution:
MODULE PrivTest;
PROCEDURE TEST;
VAR test:SHORTCHAR;
BEGIN
test := 0ABX (*number too large*)
END TEST;
END PrivTest.
If you need them, I fear you'll have to use another
variable and do some conversion:
MODULE PrivTest;
PROCEDURE TEST*;
VAR test:SHORTCHAR; number : SHORTINT;
BEGIN
test := 0ABX (*number too large*);
number := ORD(test);
HALT(0)
END TEST;
END PrivTest.TEST
For arithmetic (?) with BYTE a word of caution:
VAR b : BYTE;
FOR b := MIN(BYTE) TO MAX(BYTE) DO SomeThing END;
is an endless loop, since overflow is silently wrapped
(this is absolutely correct, given the definition of
the FOR loop in terms of a WHILE loop.
VAR s : SHORTINT;
FOR s := MIN(BYTE) TO MAX(BYTE) DO SomeThing END;
works as expected.
> -----Original Message-----
> From: Wojtek Skulski [mailto:skulski{([at]})nowhere.xy> Sent: Monday, June 17, 2002 5:43 AM
> To: BlackBox
> Cc: Wojtek Skulski
> Subject: Unsigned in Component Pascal
>
>
>
> Hi:
>
> this must be a FAQ, but let me ask. How can I treat
> a CP varaiable as an unsigned number, such that I can
> easily converse with C libraries?
>
> Specifically, the following does not compile with a message
> "number too large", even though it would fit as an unsigned
> bit pattern in the BYTE variable.
>
> Any idea how to make it compile without violating the "CP spirit"
> in some major way?
>
> MODULE TestTest;
> PROCEDURE TEST;
> VAR test:BYTE;
> BEGIN
> test := 0ABH (*number too large*)
> END TEST;
> END TestTest.
>
> As a side remark, lack of unsigned numerics in CP looks
> like a major pain to me. I did not realize this until started
> interfacing CP to Windows DLL's.
>
>
> Wojtek Skulski skulski{([at]})nowhere.xy>
>
> --------------------------------------------
>
> To unsubscribe from this mailing list, send a message
> containing the word "unsubscribe" to:
> blackbox-request{([at]})nowhere.xy>
> To get a list of valid e-mail commands and instructions on
> their usage, send a message containing the word "help" to the
> above address.
>
> Send any problem reports or questions related to this email
> list to the list owner at
> owner-blackbox{([at]})nowhere.xy>
> Current posting policy:
>
> a) To post you should use the same address by which you are
> subscribed to the mailing list. That way, the list server
> will recognize you as subscriber and forward your posting
> immediately, without creating any overhead.
>
> b) If, for some reason, you cannot post from the address, by
> which you are subscribed, your message will be moderated to
> avoid spam. Please understand that moderation will often
> cause some delay, in particular over weekends or holydays.
>
--------------------------------------------
To unsubscribe from this mailing list, send a message containing the word "unsubscribe" to:
blackbox-request{([at]})nowhere.xy
To get a list of valid e-mail commands and instructions on their usage, send a message containing the word "help" to the above address.
Send any problem reports or questions related to this email list to the list owner at
owner-blackbox{([at]})nowhere.xy
Current posting policy:
a) To post you should use the same address by which you are subscribed to the mailing list. That way, the list server will recognize you as subscriber and forward your posting immediately, without creating any overhead.
b) If, for some reason, you cannot post from the address, by which you are subscribed, your message will be moderated to avoid spam. Please understand that moderation will often cause some delay, in particular over weekends or holydays.
----boundary-LibPST-iamunique-43315283_-_-
Content-type: application/rtf
Content-transfer-encoding: base64
Content-Disposition: attachment; filename="rtf-body.rtf"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----boundary-LibPST-iamunique-43315283_-_---
Received on Mon Jun 17 2002 - 10:57:18 UTC