RE: Describing parm card dependencies in a database

[Vern Hamberg <vhamberg@xxxxxxxxxxxxxxxxxxxxxxxxx>]

Zak

Have you heard of yacc or bison or lex or flex? flex is a lexical analyzer
and bison is a parser generator, things from the *nix world - versions are
available for the 400, to run in QShell. They are free in what are known as
GNU Utilities, available from a porting site at IBM. Look at
<http://www-919.ibm.com/developer/factory/porting/gnu_utilities.html> You
create various rules, and then you get C-source for the eventual program.
Compilers have been written with these things.

HTH

Vern

At 02:09 PM 10/30/2002 -0500, you wrote:
> Ok, let me put it this way...
>
> Can anyone guide me to a starting point for parsing/evaluating an expression?
>
> For example, I think I may have rules defined something like:
> *THISB=@VALUE("ADDRDF",1,8,10,*B) which means the boolean value of the
> field being tested must equal the boolean value of the value in positions
> 8-10 of the 1st ADDRDF parm card. The expression evaluates true if both
> are blank or both have a value.
>
> But I have no clue where to start on building code to perform the
> evaluation and I don't want to get too far into defining this "language"
> before I can see how difficult it's going to be to parse. Anyone?
>
> -----Original Message-----
> From: Metz, Zak