bobsneidar at iotecdigital.com
Thu May 25 12:21:52 EDT 2017
I agree with this. I never use the fallthrough feature because it's backwards from how I think. Trying to detemine where to put the conditions in the tree to effect the correct fall through or breaks is challenging for me. But now it is what it is.
> On May 24, 2017, at 03:03 , Mark Waddingham via use-livecode <use-livecode at lists.runrev.com> wrote:
> Okay so I was perhaps a little vociferous in what I said... However, fallthrough is
> the key problem - there have been numerous subtle bugs in the engine due to it
> (similarly, switch statements without 'default' can cause subtle
> bugs too - if you add a value to an enum, but don't update all the switches which
> switch on it).
> Perhaps a better model would be to use 'continue', rather than 'break':
> switch yourName
> case "Mark"
> -- do something and finish
> case "John"
> case "Jon"
> -- do something else
> end switch
> The idea being that 'continue' in a case, jumps to the next choice to check. This works particularly nicely when you don't have an expression, so the cases can be expressions as that essentially gives you a 'match' type construct with back-tracking (quite useful for processing hierarchical arrays and transforming them - a common operation in writing compilers, for example).
> However, it would probably be better to change the switch syntax to use different keywords (perhaps choice?). The 'switch'/'case'/'break' paradigm is so ubiquitous (due to C) that making it work differently would be very jarring.
> Warmest Regards,
> Mark Waddingham ~ mark at livecode.com ~ http://www.livecode.com/
> LiveCode: Everyone can create apps
More information about the Use-livecode