Re: What good is ILE?

[Barbara Morris <bmorris@xxxxxxxxxx>]

On 2013/2/3 8:17 PM, w 4038 wrote:
> What good is ILE??
> ...
> All the complexity just increases the potential for coding errors.

For me, a big advantage of ILE is the ability to have multiple levels of 
privacy. Increased privacy tends to decrease the potential for coding 
errors.

Say A calls B to do some subtask, and you want to change the first 
parameter for B to be bigger.

If B is a separate *PGM, then B is public to the entire system. You now 
have to do some analysis to determine who is calling B, so you can 
increase the size of the variable that is being passed to B by all 
callers. If you miss one of the callers of B, you might not find out 
about the error until years later, if the storage corruption caused by 
the parameter mismatch doesn't cause an exception.

If B is a _non-exported_ procedure in the same module as A, then B is 
private to the module containing A and B. You don't have to do any 
analysis at all. It is impossible to miss compiling one of the callers 
of B. And even if you miss one of the callers of B so you don't change 
the length of its parameter, the compiler will tell you immediately.