Yeah, this has to change. In existing switches, there are no case
labels other than default, so order is irrelevant. But now that
patterns have overlapping match-sets, default should be considered to
dominate other cases, so it should go last.
Compatibility-wise, we have two choices for how to get there; carve out
a permanent exception for switches where all cases are type-restating
constant patterns, or plan to eventually get to a place where default
always comes last, even for "int" switches. If we want to get to the
latter, we should start warning on this construct now.
On 11/3/2017 5:10 PM, Tagir Valeev wrote:
Hello!
Currently the default branch can be placed in any place inside the
switch operator, e.g. like this:
switch(i) {
case 1: System.out.println("one");break;
default: System.out.println("other");break;
case 2: System.out.println("two");break;
}
In this case behavior does not change on the order of case blocks.
However in pattern matching the order of cases usually matters: if
some pattern matches, this means that the subsequent patterns will not
be checked. Does this mean that with pattern matching the default
branch makes all the subsequent case blocks unreachable? Or default
can still be located anywhere and is checked only after any other
pattern?
With best regards,
Tagir Valeev
