Re: Evaluate complex conditions

From Al Mac - catching up

>  From:    tgrider@arkansas.net (Terry Grider)
>  
>  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

C IFEQ D
C OREQ E
C OREQ F

A CASEQ B SUBROUTINE
ENDCS

ENDIF

In RPG I have nested various criteria, I also sometimes use a DUMMY 
subroutine in a CASE statement to eliminate some combinations - the DUMMY 
subroutine is a do-nothing.

> From: tgrider@arkansas.net (Terry Grider)
>  
>  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.

Query/400 can do compound selection criteria but it can get very messy.

Instead use a work file in which the intermediate file has one set of related 
criteria & then a later query selects from there, using a series of files 
each with narrower search selection.

> From: booth@martinvt.com

>  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

I have seen something like this done by FILE TRACK, but a programmer had to 
be in the development loop.

File Track from Outlook http://www.outlookcomputing.com is for playing jigsaw 
puzzle with pieces of different files, so as to construct a new file based on 
however complex rules you want to impose on extracting stuff from the other 
files.

If I correctly understand it ERROS can also do something like this for 
companies whose staff are competent in business rules manipulation.  
http://www.erros.co.uk/

The main problem of course, as someone else stated, is the vast number of 
users who are incapable of correctly stating a complex statement ... they 
need to be prompted for whether they mean AND (telling them that means both 
at the same time) or OR (telling them that means either one) ... combine that 
with people who do not know their own corporate file structure well enough to 
speciffy which data files to extract the data from.

Alister William Macintyre 
Computer Data Janitor etc. of BPCS 405 CD Rel-02 on 400 model 170 OS4 V4R3 
(forerunner to IBM e-Server i-Series 400)  @ http://www.cen-elec.com Central 
Industries of Indiana--->Quality manufacturer of wire harnesses and 
electrical sub-assemblies

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