Hi list
Java 11 (or perhaps 12) might see a new functionality known as switch
expressions (https://bugs.openjdk.java.net/browse/JDK-8192963
<https://bugs.openjdk.java.net/browse/JDK-8192963>).
While the current Groovy implicit return functionality works with the switch
statement as-is, the switch expression is a more general construct, basically
it is to the conditional operator (a ? b : c) what the switch statement is to
if/then/else-if/else. An example:
int numLetters = switch (day) {
case MONDAY, FRIDAY, SUNDAY -> 6;
case TUESDAY -> 7;
case THURSDAY, SATURDAY -> 8;
case WEDNESDAY -> 9;
};
with
case LABEL -> expression;
essentially sugar for
case LABEL: break expression;
As I see it: It could add utility to the Groovy language, and adopting it would
keep up the the Java-compatibility gap, which I think is a valuable
gateway-drug to discovering the joys of Groovy. The "break <expression> syntax
isn't pretty, but the arrows look fine and incur no syntax compatibility
problem, as far as I can see.
Now, this being Groovy, the cases should surely support the extended
"isCase"-support, as described so well here:
http://mrhaki.blogspot.dk/2009/08/groovy-goodness-switch-statement.html
<http://mrhaki.blogspot.dk/2009/08/groovy-goodness-switch-statement.html>
So, three questions remain:
1) Useful or not?
2) This Java compatibility - is it still a thing? I remember a similar proposal
a little while back, but this would align better with Java.
3) This could be implemented using existing AST's if we really want to, but it
would be clumsy. This AST transformer compatibility - is it still a thing?
-Jesper
