I like that arguments will be readonly by default. But when I look at my current code, I see that I would be typing " is rw" quite a lot, which in my opinion is too long for a thing that occurs very often.
Every such situation in my code is a foreach loop. A thing that in Perl 6 will mostly be used with the pointy sub declaration syntax. If I'm not mistaken, <-> is still available. It communicates "bidirectional" and that is more or less the same as read/write access. I'm proposing for zip(@foos, @bars, @xyzzies) <-> $foo, $bar, $xyzzy { ... } for %quux.kv <-> $key, $value { ... } to mean for zip(@foos, @bars, @xyzzies) -> $foo is rw, $bar is rw, $xyzzy is rw { ... } for %quux.kv -> $key is rw, $value is rw { ... } Comments, anyone? Juerd