On 21 Sep 2015, at 16:45, Remi Forax <fo...@univ-mlv.fr> wrote: > I agree with Stephen. > > Calling the function interface with the name ...Exception seems very wrong to > me. >
Agreed, need to think of a better name. One solution is to remove it all together :-) see below. > The convention of ArrayIOOBE or StringIOOBE is to just report the bad index > with no further info, > currently with your code it's not possible to write > checkIndex(index, ArrayIndexOutOuBoundException::new). > > so the functional interface for checkIndex should be int -> Object or long -> > Object if you change ArrayIOOBE and StringIOOBE to store a long. > This functional Interface already exists under the name > java.util.function.LongFunction. > The friction here is trying to cater for the existing use-cases in the JDK, after a cursory 5 minute search you will find many conventions :-) From the use-cases i have looked at so far I believe it’s possible to support nearly all with BiFunction<Integer, Integer, RuntimeException> (i started out with that in mind), in some cases a process of elimination can be used for reporting. Other use-cases could be supported with capture. There is a use-case in AbstractStringBuilder that requires all three values, that is the only one i have found so far in the JDK. I would be interested to know if there are others and also if people are doing that in their own code too. I would be happy to sacrifice the use-case in AbstractStringBuilder for using BiFunction<Integer, Integer, RuntimeException>, and add appropriate constructors or factory methods on the common exception types for method ref usage. Paul. > For the two other methods that checks several index, again the convention is > to report the bad index / size, so a LongFunction is enough too, > yes, it means that you can not check several index at once with things like > (a < 0) | (b < 0) but because the semantics you propose is different > from what is usually done, you will not be alble to use those methods inside > the JDK without introducing incompatibilities. > > cheers, > Rémi
