Re: How defensively should you code your procedures?

On 7/17/2015 7:21 AM, Wilson, Jonathan wrote:

...
(1) I can live with better type checking on indicators at compile time,
the specific code in the original source used a tri-state - blank for
not initialised and *ON/*OFF for state (roll up/Down, blank meant no
roll key pressed... it made sense at the time.). But! The runtime does
no such checking, I can move a character field not containing "1"/"0"
into an indicator and it doesn't complain during the move or when
tested, however the result can be unpredictable. It also changed how
CLEAR worked, originally it cleared the indicator defined field (blanked
it) but then with RPG IV changed to "0"ing it.

I would hunt down all those tri-state "indicators" and change them to
true character. The main risk is that somebody codes "if myInd" by
mistake instead of "if myind = rollUp". If the value is neither '0' nor
'1', it's undefined behaviour whether the "if" statement would return
true or false.