----- Mail original ----- > De: "John Rose" <john.r.r...@oracle.com> > À: "Remi Forax" <fo...@univ-mlv.fr> > Cc: "Jorn Vernee" <jver...@openjdk.java.net>, "core-libs-dev" > <core-libs-dev@openjdk.java.net> > Envoyé: Vendredi 9 Avril 2021 20:01:18 > Objet: Re: RFR: 8263087: Add a MethodHandle combinator that switches over a > set of MethodHandles
Hi John, > On Apr 9, 2021, at 9:55 AM, Remi Forax <fo...@univ-mlv.fr> wrote: >> >> I think the combinator should be lookupswitch which is more general than >> tableswitch with a special case when generating the bytecode to generate a >> tableswitch instead of a lookupswitch if the indexes are subsequent. > > We can get there in the simpler steps Jorn has outlined. I fail to see how it can work. > > The combinator is much simpler if the case numbers are implicit in [0,N). Then > it’s natural to filter on the [0,N) input as a separately factored choice. An array of MethodHandles + a default method handle is simpler than an array of sorted ints + an array of MethodHandles + a default method, but not much simpler. > That also scales to pattern-switch. yes, for all the switches, pattern-switch, enum-switch but not for the string switch which requires a lookup switch. Can you outline how to use the tableswitch combinator in the case of a switch on strings ? > > I agree with the choice to have N call sites. It’s possible to build the one > call site version on top using constant combinators but not vice versa. yes, Rémi
