Re: Quieter Monitors

On Feb 23, 2010, at 12:51 PM, rpg400-l-request@xxxxxxxxxxxx wrote:

As far as seeing what the code path should be, how it this worse than using
MONITOR to avoid e.g. array index errors:

// Check for errors before processing
if a = 0 or
array.ptr(a) = null or
array.len(a) < 0;
throwError;
endif;

// Load newvar
varptr = array.ptr(a);
newvar = %subst( var : 1 : array.len(a) );

I know - it's a nice simple example. Can you show me an example of code that
uses MONITOR that couldn't equally clearly be written using specific error
checks?

Maybe it's the comments that make it clear? <grin>

You've provided your own answer Rory. Without the comments the code would tell me nothing.

To me this is really important in a maintenance context where I need to scan and understand as much code as quickly as possible. If I'm trying to understand the intended flow of the code, which is more obvious - your version or mine:

// Load newvar
Monitor;

varptr = array.ptr(a);
newvar = %subst( var : 1 : array.len(a) );
On-error;
throwError;

To me all the pointer testing etc. simply detracts from the point of the exercise which is to set a new value. I can also see exactly how the programmer intends to handle an error. No comments needed.

Jon Paris

www.Partner400.com
www.SystemiDeveloper.com