Re: Evaluate complex conditions

Here's a way I solved the same sort of issue recently: 

Firstly there were only a few fields, less than 6, that were appropriate 
for users to make a choice on.  The choice they asked for was to be able 
to include or exclude certain field values in combination with other field 
values.  To do it I made a selection screen with an entry area for each 
selection item and  drop-down box w/subfile so they could select one or 
more valid values for each field. Each entry area also had an associated 
radio button for include/exclude.  One selection item had 8 valid choices 
so I added a checkbox group for it.   By using include and exclude choices 
there is no need for the and/or choice; the choices are ALL "and".

Then, I added the ability to save the last settings used by a user so the 
user could do it over and over, selecting small changes for slightly 
different reports. 

The end result is an easily understood green screen application for the 
average user, and a great deal of flexibility for the data that is of 
concern, yet no chance for the user to get caught up in trivial or 
duplicate selection processes.   (don't you just hate having to explain 
that using both "include" and "exclude" criteria on the same field value 
will give unexpected results?)

This limits choices and flexibility but my experience is that these limits 
are a "good thing"tm.



_______________________
Booth Martin
Booth@MartinVT.com
http://www.MartinVT.com
_______________________




Terry Grider <tgrider@arkansas.net>
Sent by: owner-midrange-l@midrange.com
10/23/2000 04:37 PM
Please respond to MIDRANGE-L

 
        To:     MIDRANGE-L@midrange.com
        cc: 
        Subject:        Re: Evaluate complex conditions

You're on the right track Booth except I'm not brave enough to allow TOTAL
english syntax.  I was just hoping to be able to provide simple = , not=, 
<, >,
not>, not<  type compares between field names and literal values, which I 
have
coded for and have working at this point, but only with simple single 
level
conditions connected by a series of either 'ANDs' or 'ORs'.  Naturally, 
first
time a user wanted to try out my little query tool, they needed support 
for
complex, multi-level conditions.  Isn't that always the way it goes!

booth@martinvt.com wrote:

> Oh man, I think it just dawned on me what he's asking for:
>
> You want to give users a long field to type into, and have them type a
> question which you will then parse and assemble into a useable RPGIV
> calculation?   For example, something like
>
> "List everyone that lives in Springfield, owes us money, and hasn't 
bought
> anything for 94 days.   By the way, they have to live in Missouri,
> Illinois, or Canada.  Include their address and phone number on the 
list.
> List last name first, in order by area code and exchange."
>
> That sort of thing?
>
> _______________________
> Booth Martin
> Booth@MartinVT.com
> http://www.MartinVT.com
> _______________________
>
> D.BALE@handleman.com
> Sent by: owner-midrange-l@midrange.com
> 10/23/2000 01:50 PM
> Please respond to MIDRANGE-L
>
>
>         To:     MIDRANGE-L@midrange.com
>         cc:
>         Subject:        Re: Evaluate complex conditions
>
> You mean like:
>
>      c                   Eval      Truth = a = b and (c = d or c = e or 
c
> = f)
>
> Ya, sure, RPG-IV!
>
> Dan Bale
> IT - AS/400
> Handleman Company
> 248-362-4400  Ext. 4952
>
> -------------------------- Original Message --------------------------
> Sorry guys,  I didn't do a very good job of explaining what I was 
looking
> for.
> I don't mean I want code that is an example of testing for complex
> conditions,
>  I
> mean I'm looking for code that will evaluate statements like the one in 
my
> original example and determine the truth of the statement.  You see, I'm
>  writing
> a query tool and I want the user to be able to provide selection 
criteria
> in
>  an
> english style IF format similar to cobol or other query tools I've seen. 
I
>  can
> currently handle simple criteria with "and/or" connectors, but I can't
> seem to
> come up with a good method for handling multiple levels of parenthesis.
>
> Terry Grider wrote:
>
> > Has anyone ever written or seen an example of program code designed to
> > evaluate complex conditions?  For example, if you wanted to evaluate a 
=
> > b and (c = d or c = e or c = f).  I'm looking for something that can 
do
> > multiple levels of parenthesis and all "and/or" combinations.
> >
> > --
> > Terry Grider
> > tgrider@arkansas.net
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--
Terry Grider
tgrider@arkansas.net


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