Indexing access for Lists and Maps considered harmful?

[Paul Benedict]

I am not a fan of this proposal in general. Two things to comment on:

(1) Collections are located in java.util, but the JLS can only
reference classes in java.lang, correct? If I have my facts correct
(doubting), this enhancement would set a new precedent by having a
language feature reach into a non-lang package.

(2) I don't see the benefit-to-cost ratio paying off. I wouldn't want
this new language feature accepted without (a) a full working
prototype and (b) a large passage of time to get through these design
issues. What might make sense within 3 months of thought (coin dev's
time limit) may look poorly thought out after a year's time. What
comes to mind is JSR-308, JSR-305, and Neal's closures because their
prototypes allow the community to weigh and play features before
inclusion -- if ever whenever. When there is contention, the best
solution is to prove out the idea with sweat and code.

Paul