----boundary-LibPST-iamunique-337536635_-_-
Content-type: text/plain
> -----Original Message-----
> From: Gérard Meunier [mailto:gemeu{([at]})nowhere.xy
>
> > recently I ran into some mischief using the predeclared Compiler
> > Function CAP because the result was somewhat unexpected.
> The results
> > and the problem can be found in the following coded text, perhaps
> > somebody knows an answer:
>
> Apparently, this function substracts 32 (20H) from the code
> of many characters. It's correct for lower case letters, but
> a little surprising for digits or punctuations. I don't know
> why this behaviour has been chosen. I never use CAP myself
> but Strings.Upper, which works properly, but may be a little slower.
>
CAP is useful where execution speed is absolutely crucial. Timing tests
indicate that it is about 4 times faster than Strings.Upper.
It is no accident that capital letters in the Latin-1 character set only
differ from the corresponding lowercase letter by one bit. I don't know
how exactly how BlackBox does it but typically a compiler just needs to
generate a single bitwise AND operation to clear one bit to implement
CAP. Unlike a call to Strings.Upper, no function call / return or
pushing / popping parameters to / from the stack is involved.
I find it useful (and safe) in situations like:
IF (CAP(ch) >= 'A') OR (CAP(ch) <= 'Z') THEN
instead of
IF ((ch >= 'a') & (ch <= 'z')) OR ((ch >= 'A') & (ch <= 'Z')
However, if speed is not a priority, and you want to take the safe
route, your recommendation to use Strings.Upper is a good one.
Chris Burrows
CFB Software
http://www.cfbsoftware.com/gpcp
--------------------------------------------
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-337536635_-_-
Content-type: application/rtf
Content-transfer-encoding: base64
Content-Disposition: attachment; filename="rtf-body.rtf"
e1xydGYxXGFuc2lcYW5zaWNwZzEyNTJcZnJvbXRleHQgXGRlZmYwe1xmb250dGJsDQp7XGYwXGZz
d2lzc1xmY2hhcnNldDAgQXJpYWw7fQ0Ke1xmMVxmbW9kZXJuIENvdXJpZXIgTmV3O30NCntcZjJc
Zm5pbFxmY2hhcnNldDIgU3ltYm9sO30NCntcZjNcZm1vZGVyblxmY2hhcnNldDAgQ291cmllciBO
ZXc7fX0NCntcY29sb3J0YmxccmVkMFxncmVlbjBcYmx1ZTA7XHJlZDBcZ3JlZW4wXGJsdWUyNTU7
fQ0KXHVjMVxwYXJkXHBsYWluXGRlZnRhYjM2MCBcZjBcZnMyMCA+IC0tLS0tT3JpZ2luYWwgTWVz
c2FnZS0tLS0tXHBhcg0KPiBGcm9tOiBHXCdlOXJhcmQgTWV1bmllciBbbWFpbHRvOmdlbWV1QGZy
ZWUuZnJdIFxwYXINCj4gXHBhcg0KPiA+IHJlY2VudGx5IEkgcmFuIGludG8gc29tZSBtaXNjaGll
ZiB1c2luZyB0aGUgcHJlZGVjbGFyZWQgQ29tcGlsZXIgXHBhcg0KPiA+IEZ1bmN0aW9uIENBUCBi
ZWNhdXNlIHRoZSByZXN1bHQgd2FzIHNvbWV3aGF0IHVuZXhwZWN0ZWQuIFxwYXINCj4gVGhlIHJl
c3VsdHMgXHBhcg0KPiA+IGFuZCB0aGUgcHJvYmxlbSBjYW4gYmUgZm91bmQgaW4gdGhlIGZvbGxv
d2luZyBjb2RlZCB0ZXh0LCBwZXJoYXBzIFxwYXINCj4gPiBzb21lYm9keSBrbm93cyBhbiBhbnN3
ZXI6XHBhcg0KPiBccGFyDQo+IEFwcGFyZW50bHksIHRoaXMgZnVuY3Rpb24gc3Vic3RyYWN0cyAz
MiAoMjBIKSBmcm9tIHRoZSBjb2RlIFxwYXINCj4gb2YgbWFueSBjaGFyYWN0ZXJzLiBJdCdzIGNv
cnJlY3QgZm9yIGxvd2VyIGNhc2UgbGV0dGVycywgYnV0IFxwYXINCj4gYSBsaXR0bGUgc3VycHJp
c2luZyBmb3IgZGlnaXRzIG9yIHB1bmN0dWF0aW9ucy4gSSBkb24ndCBrbm93IFxwYXINCj4gd2h5
IHRoaXMgYmVoYXZpb3VyIGhhcyBiZWVuIGNob3Nlbi4gSSBuZXZlciB1c2UgQ0FQIG15c2VsZiBc
cGFyDQo+IGJ1dCBTdHJpbmdzLlVwcGVyLCB3aGljaCB3b3JrcyBwcm9wZXJseSwgYnV0IG1heSBi
ZSBhIGxpdHRsZSBzbG93ZXIuXHBhcg0KPiBccGFyDQpccGFyDQpDQVAgaXMgdXNlZnVsIHdoZXJl
IGV4ZWN1dGlvbiBzcGVlZCBpcyBhYnNvbHV0ZWx5IGNydWNpYWwuIFRpbWluZyB0ZXN0c1xwYXIN
CmluZGljYXRlIHRoYXQgaXQgaXMgYWJvdXQgNCB0aW1lcyBmYXN0ZXIgdGhhbiBTdHJpbmdzLlVw
cGVyLiBccGFyDQpccGFyDQpJdCBpcyBubyBhY2NpZGVudCB0aGF0IGNhcGl0YWwgbGV0dGVycyBp
biB0aGUgTGF0aW4tMSBjaGFyYWN0ZXIgc2V0IG9ubHlccGFyDQpkaWZmZXIgZnJvbSB0aGUgY29y
cmVzcG9uZGluZyBsb3dlcmNhc2UgbGV0dGVyIGJ5IG9uZSBiaXQuIEkgZG9uJ3Qga25vd1xwYXIN
CmhvdyBleGFjdGx5IGhvdyBCbGFja0JveCBkb2VzIGl0IGJ1dCB0eXBpY2FsbHkgYSBjb21waWxl
ciBqdXN0IG5lZWRzIHRvXHBhcg0KZ2VuZXJhdGUgYSBzaW5nbGUgYml0d2lzZSBBTkQgb3BlcmF0
aW9uIHRvIGNsZWFyIG9uZSBiaXQgdG8gaW1wbGVtZW50XHBhcg0KQ0FQLiBVbmxpa2UgYSBjYWxs
IHRvIFN0cmluZ3MuVXBwZXIsIG5vIGZ1bmN0aW9uIGNhbGwgLyByZXR1cm4gb3JccGFyDQpwdXNo
aW5nIC8gcG9wcGluZyBwYXJhbWV0ZXJzIHRvIC8gZnJvbSB0aGUgc3RhY2sgaXMgaW52b2x2ZWQu
XHBhcg0KXHBhcg0KSSBmaW5kIGl0IHVzZWZ1bCAoYW5kIHNhZmUpIGluIHNpdHVhdGlvbnMgbGlr
ZTpccGFyDQpccGFyDQogIElGIChDQVAoY2gpID49ICdBJykgT1IgKENBUChjaCkgPD0gJ1onKSBU
SEVOXHBhcg0KXHBhcg0KaW5zdGVhZCBvZlxwYXINClxwYXINCiAgSUYgKChjaCA+PSAnYScpICYg
KGNoIDw9ICd6JykpIE9SICgoY2ggPj0gJ0EnKSAmIChjaCA8PSAnWicpXHBhcg0KXHBhcg0KSG93
ZXZlciwgaWYgc3BlZWQgaXMgbm90IGEgcHJpb3JpdHksIGFuZCB5b3Ugd2FudCB0byB0YWtlIHRo
ZSBzYWZlXHBhcg0Kcm91dGUsIHlvdXIgcmVjb21tZW5kYXRpb24gdG8gdXNlIFN0cmluZ3MuVXBw
ZXIgaXMgYSBnb29kIG9uZS5ccGFyDQpccGFyDQpDaHJpcyBCdXJyb3dzXHBhcg0KQ0ZCIFNvZnR3
YXJlXHBhcg0KaHR0cDovL3d3dy5jZmJzb2Z0d2FyZS5jb20vZ3BjcFxwYXINClxwYXINClxwYXIN
ClxwYXINClxwYXINCi0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0t
XHBhcg0KXHBhcg0KVG8gdW5zdWJzY3JpYmUgZnJvbSB0aGlzIG1haWxpbmcgbGlzdCwgc2VuZCBh
IG1lc3NhZ2UgY29udGFpbmluZyB0aGUgd29yZCAidW5zdWJzY3JpYmUiIHRvOlxwYXINCiAgIGJs
YWNrYm94LXJlcXVlc3RAb2Jlcm9uLmNoXHBhcg0KXHBhcg0KVG8gZ2V0IGEgbGlzdCBvZiB2YWxp
ZCBlLW1haWwgY29tbWFuZHMgYW5kIGluc3RydWN0aW9ucyBvbiB0aGVpciB1c2FnZSwgc2VuZCBh
IG1lc3NhZ2UgY29udGFpbmluZyB0aGUgd29yZCAiaGVscCIgdG8gdGhlIGFib3ZlIGFkZHJlc3Mu
XHBhcg0KXHBhcg0KU2VuZCBhbnkgcHJvYmxlbSByZXBvcnRzIG9yIHF1ZXN0aW9ucyByZWxhdGVk
IHRvIHRoaXMgZW1haWwgbGlzdCB0byB0aGUgbGlzdCBvd25lciBhdFxwYXINCiAgIG93bmVyLWJs
YWNrYm94QG9iZXJvbi5jaFxwYXINClxwYXINCkN1cnJlbnQgcG9zdGluZyBwb2xpY3k6XHBhcg0K
XHBhcg0KYSkgVG8gcG9zdCB5b3Ugc2hvdWxkIHVzZSB0aGUgc2FtZSBhZGRyZXNzIGJ5IHdoaWNo
IHlvdSBhcmUgc3Vic2NyaWJlZCB0byB0aGUgbWFpbGluZyBsaXN0LiBUaGF0IHdheSwgdGhlIGxp
c3Qgc2VydmVyIHdpbGwgcmVjb2duaXplIHlvdSBhcyBzdWJzY3JpYmVyIGFuZCBmb3J3YXJkIHlv
dXIgcG9zdGluZyBpbW1lZGlhdGVseSwgd2l0aG91dCBjcmVhdGluZyBhbnkgb3ZlcmhlYWQuXHBh
cg0KXHBhcg0KYikgSWYsIGZvciBzb21lIHJlYXNvbiwgeW91IGNhbm5vdCBwb3N0IGZyb20gdGhl
IGFkZHJlc3MsIGJ5IHdoaWNoIHlvdSBhcmUgc3Vic2NyaWJlZCwgeW91ciBtZXNzYWdlIHdpbGwg
YmUgbW9kZXJhdGVkIHRvIGF2b2lkIHNwYW0uIFBsZWFzZSB1bmRlcnN0YW5kIHRoYXQgbW9kZXJh
dGlvbiB3aWxsIG9mdGVuIGNhdXNlIHNvbWUgZGVsYXksIGluIHBhcnRpY3VsYXIgb3ZlciB3ZWVr
ZW5kcyBvciBob2x5ZGF5cy5ccGFyDQp9
----boundary-LibPST-iamunique-337536635_-_---
Received on Thu Sep 16 2004 - 08:14:51 UTC