RE: "extract" command enhancement(subfiles and BIFs)

I've written text based screens in C and I'll readily admit that it's a lot
of work.  Some of the stuff you can reuse like position cursor routines, and
other stuff you can buy (if you're lucky) libraries for.  One thing I had to
do in a class was to write a getline() function that supported insert,
overstrike, masked input, home and end keys, right and left justification,
and accomodated input fields of any length up to an arbitrary size.  It was
hard work for a novice programmer and took me a long time.  I learned a lot
about programming from it including techniques I could use in many
situations that had nothing to do with screens. 

When I was done, I also had something I could use over and over again by
just plugging it in to a program.  (All right, the AS/400 equivalent is
pretty much done for you in DDS.)  

The thing that bothers me about AS/400 display programming is that logic
plays a minor role.  What's important is knowing the right keywords to
apply.  I think the difference between the arcana of display files and "ANY
programming situation" is the sheer number of arbitrary things you need to
know.  In many programming tasks you need to know fewer than 20 reserved
words, some of which are arithmetic operators that many people have seen
before.  How many reserved words were there in K&R C?  I know there's a few
more now, but think how many there are for display files.  It is a matter of
personal taste and for me, middle aged memory.  If I'd started display file
programming when I had short term memory, I probably would remember keywords
instead of baseball statistics or the lyrics to top 10 songs from 1956.  

I do agree that it's much faster to put up a simple display on the AS/400
than other text based environments I've seen.  I just don't like what you
need to do to do it.<g>

A subfile by itself probably shouldn't take 2 days to write, but an
application that does update, add, delete, and offers a few bells and
whistles like position to logic and programmatic error checking could easily
take two days if you include a little time for testing. 
> -----Original Message-----
> From: Scott Klement [mailto:infosys@klements.com]
> Sent: Wednesday, September 22, 1999 8:12 AM
> To: RPG400-L@midrange.com
> Subject: Re: "extract" command enhancement(subfiles and BIFs)
> 
> 
> Wow.
> 
> Okay, maybe I'm nuts (yes, I probably am nuts, and will probably get
> a few replies telling me so) but I always thought display files were
> a very easy and convienient way to do plain-text screens.
> 
> Have you ever tried to write programs with display-file-like
> functionality on PCs?  or for UNIX machines?
> 
> You write a whole routine that handles the cursor movement... when
> someone presses tab or leaves the field, you manually move the cursor
> to the next field.  If you want to handle something like right-
> adjusting, or whatever, you have to do that in your code.  etc, etc.
> It can takes hours of debugging just to get cursor movement to do
> what you wanted it to do :)
> 
> To do a simple screen like this in a display file?  10 minutes with
> SDA, or maybe 30 mins without SDA.  It does all the work for you.
> 
> Subfiles?  Well, I guess you do these on PC/UNIX much the same way
> you did it on the S/36.  With arrays.  Except, again, you have to
> write routines to do EVERYTHING.
> 
> Maybe I'm weird (okay, we're back to that again) but subfiles don't
> take me long to write.   Even the people that I train who have no
> prior exposure to the AS/400 seem to be able to pick up subfiles and
> write them in less than the 2 days that someone else mentioned on
> the list.  And we don't use templates (tho programmers are welcome
> to make their own templates, if they wish)
> 
> Granted, if the application is complex, it may take weeks to write
> the program -- but this isn't because of the subfiles, its because of
> the other things that need to be done!
> 
> Display files are a GREAT tool, and they are QUITE easy to use, they
> save me a lot of time and make me far more productive.
> 
> I seriously wonder why you'd think that they're a "file sewer" thats
> based on "memorizing arcane reserved words".   Really, you could
> apply that sentence to ANY programming situation -- if you don't like
> memorizing reserved words (i.e. a programming language) why are you
> programming?
> 
> 
> 
> Joel Fritz <JFritz@sharperimage.com> wrote:
> <SNIP>
> > I definitely agree with you and Booth about subfiles.  The whole
> >  display
> > file sewer is based on memorizing arbitrary arcane reserved words.
> >  Seems
> > like a verb to do something like clear the subfile would make more
> >  sense
> > than setting on an indicator and writing to the control record,
> >  though.
> >
> > How many people out there use more than ten or so display file
> >  keywords?
> > Of those, how many can use most of them without looking them up?
> > How many can use them in SEU rather than SDA?
> <SNIP>
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