On Thu, 2018-01-25 at 07:38 +0100, Georg Chini wrote: > On 25.01.2018 00:26, Tanu Kaskinen wrote: > > On Wed, 2018-01-24 at 22:01 +0100, Georg Chini wrote: > > > On 24.01.2018 02:10, Tanu Kaskinen wrote: > > > > How does validating the brace correctness prevent some values being > > > > used before all values have been parsed? You're only enforcing brace > > > > correctness, but if you have a list of doubles, any of the double > > > > values can be invalid. Nothing is preventing the application from using > > > > the first values of the list before noticing that a value later in the > > > > list is invalid. > > > > > > > > I didn't claim that my approach was any better in this regard, you were > > > > just making impossible-sounding claims about the benefits of your > > > > approach. > > > > > > I can only repeat myself: My example above shows how this > > > helps detecting errors before any values are used at all. The > > > point is, that the consistency check is done before the values > > > are parsed. This means when pa_split_message_response() > > > returns a list, the whole list is already checked for consistency > > > (with the exception of the outer, implicit list). This does neither > > > prevent later lists from having issues nor does it help against > > > wrong list values, but at least you should never hit a parse > > > error within a list. I think it is a big benefit to know in advance > > > that a list is at least consistent. > > > > I just don't see the big benefit. You have to do error checking for the > > individual values in any case. The benefit of having the list > > formatting check early is that reading the individual values can't fail > > due to list formatting errors, but since there are other error cases, > > the code complexity for reading a value is exactly the same as without > > any early list formatting checks (assuming that the application doesn't > > care about the exact failure reason). > > Strange that you don't see the benefit. In my example, if the y1 > y2 are very high but still acceptable volume values, not catching > the parse error in advance could even lead to damage of > hardware or ears. So this "big benefit" is only for the cases where an application uses some parameter values before the whole message has been parsed. That's always a bad idea, so nobody should be doing that, and therefore the benefit seems very small to me. -- Tanu https://liberapay.com/tanuk https://www.patreon.com/tanuk
