RE: %Trim dilemma

Just wait...
On-Error begat... (to be continued Tuesday)


-Bob Cozzi
www.RPGxTools.com
RPG xTools - Enjoy programming again.


-----Original Message-----
From: rpg400-l-bounces+cozzi=rpgiv.com@xxxxxxxxxxxx
[mailto:rpg400-l-bounces+cozzi=rpgiv.com@xxxxxxxxxxxx] On Behalf Of Booth
Martin
Sent: Friday, January 27, 2006 2:42 PM
To: RPG programming on the AS400 / iSeries
Subject: Re: %Trim dilemma

This is a new one.  a hyphenated opcode???



Holden Tommy wrote:
> <snip> Now let's get on with
> the real problems in RPG IV, like hyphens in opcode names! <vbg></snip>
> 
> Umm can we at least get the opcodes..  Lol
> 
> Hyphenated opcodes that work to spec > than no frickin' opcode IMO
> hehe... 
> 
> 
> Thanks,
> Tommy Holden
> 
> 
> -----Original Message-----
> From: rpg400-l-bounces@xxxxxxxxxxxx
> [mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of Bob Cozzi
> Sent: Friday, January 27, 2006 2:05 PM
> To: 'RPG programming on the AS400 / iSeries'
> Subject: **SPAM** RE: %Trim dilemma
> 
> What's a "NULL Variable"?
> Do you mean a field that can contain a X'00' or is considered null (as
> in
> *NULL in RPG IV)?
> Does Oracle use null-terminated strings? If so, then a pointer to a null
> value is an empty string. A null pointer is the same in Unix-based C as
> it
> is in RPG IV, for the most part. 
> Often C compilers map a 0 or X'00' to the word "null". 
> So  if (mystring == null) means, does the field contain a X'00' in
> position
> 1 (or offset zero of you're a C person).
> In RPG IV, you can use %str() to move from/to null-terminated strings.
> But
> you're right, there is not "full null support" (whatever that might
> mean,
> but I agree that it seems that way).
> 
> So if the l-value's length is ZERO, how many 9's should it be compared
> with
> in order for it to be false? Based the way *ALL'9' works, by matching
> its
> corresponding value's length, that would be zero 9's. Hence, they would
> be
> equal.
> I've written tons of C code, and often have to check for a null
> address/ptr
> as well as a null value (pointing to X'00') to make sure I'm not
> screwing
> things up. Doing the following in this case, doesn't seem to strange. 
> I think this is just one of education, and acceptance. Now let's get on
> with
> the real problems in RPG IV, like hyphens in opcode names! <vbg>
> 
> if %len(%Trim(myField)) > 0
>     and %Trim(myField)= *ALL'9'
> // now we're cookin'
> endif 
> 
> -Bob Cozzi
> www.RPGxTools.com
> RPG xTools - Enjoy programming again.
> 
> 
> -----Original Message-----
> From: rpg400-l-bounces@xxxxxxxxxxxx
> [mailto:rpg400-l-bounces@xxxxxxxxxxxx]
> On Behalf Of Wilt, Charles
> Sent: Friday, January 27, 2006 1:52 PM
> To: RPG programming on the AS400 / iSeries
> Subject: RE: %Trim dilemma
> 
> That's debatable, particularly when dealing with a language, like RPG,
> that doesn't provide full NULL support.
> 
> If you consider strings to be sets of characters, then you'd consider
> that in set theory the NULL set and the EMPTY set are one and the same.
> 
> Interesting tidbit, Oracle treats EMPTY strings as NULL strings and vice
> versa.
> 
> However, given that DB2 doesn't treat NULL strings as EMPTY strings, and
> given that RPG doesn't support NULL variables, I probably should have
> said empty instead of NULL <grin>
> 
> 
> Charles Wilt
> --
> iSeries Systems Administrator / Developer
> Mitsubishi Electric Automotive America
> ph: 513-573-4343
> fax: 513-398-1121
>   
> 
>> -----Original Message-----
>> From: rpg400-l-bounces@xxxxxxxxxxxx 
>> [mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of 
>> Matt.Haas@xxxxxxxxxxx
>> Sent: Friday, January 27, 2006 2:10 PM
>> To: rpg400-l@xxxxxxxxxxxx
>> Subject: RE: %Trim dilemma
>>
>> This isn't comparing null strings. It's comparing empty 
>> strings which is
>> very different from null.
>>
>> Matt 
>>
>