Re: RE: What bugs you about KLISTs in RPG IV?

Vijosh A <VijoshA@alfuttaim.co.ae> wrote:
> Your idea is interesting.
>
> But let me draw your attention to a problem that comes to my mind- I
> suppose you do not have a KLIST and  as it often happens there are
>  changes
> to key fields (although not frequently). So if I use your method the
>  I will
> have to change the same in  many a places. Especially when you are
>  using
> physical file fields in the KLIST. This may make maintenance
>  difficult. So
> therefore I would still prefer to use KLISTS.


I honestly don't see how it'd be any different making these changes
using KLISTs vs. the free-form syntax.

okay, here is a keylist example:

C     KeyList       KLIST
C                   KFLD                    KeyFld1           5 0
C                   KFLD                    KeyFld2          10
C                   KFLD                    KeyFld3          15

C     KeyList       CHAIN     File                               10

C* 50 lines later:
C     KeyList       CHAIN     File                               11

C* 100 Lines later:
C     KeyList       CHAIN     File                               12


Here is the same thing, with free-form syntax....

D KeyFld1         S              5  0
D KeyFld2         S             10A
D KeyFld3         S             15A

CF   CHAIN(KeyFld1:KeyFld2:KeyFld3) File

C* 50 lines later
CF   CHAIN(KeyFld1:KeyFld2:KeyFld3) File

C* 100 lines later
CF   CHAIN(KeyFld1:KeyFld2:KeyFld3) File


In both cases you only have to change the keys WHERE THEY ARE DEFINED.
In BOTH cases, this is only in ONE PLACE.

How is it different for the purposes of maintenance?

Yes, you don't HAVE to specify the same variables on each chain
statement with the freeform expression, but you also don't have to
with the KLIST!

For example:

C     KeyList       KLIST
C                   KFLD                    KeyFld1           5 0
C                   KFLD                    KeyFld2          10
C                   KFLD                    KeyFld3          15

C     KeyList       CHAIN     File                               10

C* 50 lines later:
C     KeyList2      KLIST
C                   KFLD                    Key2Fld1          5 0
C                   KFLD                    Key2Fld2         10
C                   KFLD                    Key2Fld3         15

C     KeyList2      CHAIN     File                               11


Would not be any "easier to maintain" than:

D KeyFld1         S              5  0
D KeyFld2         S             10A
D KeyFld3         S             15A

D Key2Fld1        S              5  0
D Key2Fld2        S             10A
D Key2Fld3        S             15A

CF   CHAIN(KeyFld1:KeyFld2:KeyFld3) File

C* 50 lines later
CF   CHAIN(Key2Fld1:Key2Fld2:Key2Fld3) File


When you're updating all of your programs because the keys have
changed, you currently have to do this:

1) Search your program for all the CHAIN, SETLL, DELETE & READE
     op-codes for that file.
2) Find all of the keylists referenced in step 1, and determine what
     variables they are using.
3) Find out where those variables are used, and change their defs...


However, with the proposed, new, free-form method you would:

1) Search for all the CHAIN, SETLL, DELETE and READE statements
     just like above.
2) Check the definitions for the variables used, and update them,
     just like step #3 above.

Since the variables are referenced directly, you no longer have to
do step #2.


So, I'm very sorry, but no matter how I look at it, I can't see how
this makes maintenance MORE DIFFICULT!!!!
>
> Another problem you have not addressed is the - facility to use F11
>  a
> KLIST. This is facility will be useful and will be highly appreciate
>
> Thanks
>
> Cheers
>
> Vijosh A
> Systems & Software
> 123 , SDF-  4,  SEEPZ
> Bombay India.


Theres a very simple solution to the whole "debug a whole keylist"
problem.   Just put all of your keys in a data structure somewhere,
and debug THAT.

Maybe I'm weird, but its only once in a blue moon that I need to
debug a keylist, and hitting F11 (or typing eval varname) for 2 or 3
different variables in a keylist doesn't bother me at all.  If it did,
I'd make a data structure that contained all of my keys, just to make
it easier to debug them.

Scott Klement
Information Systems Manager
Klement's Sausage Co, Inc.
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