What should an empty block evaluate to?

[ltratt]

What should this program print?

empty_block = (
    run = (
        [] value println.
    )
)

Java SOM prints "instance of Block1". There's nothing wrong with that per se, but it wasn't what I was expecting because a) (at least as far as I know) blocks can't get access to their instances under normal circumstances b) methods return self unless otherwise specified. I wondered if this was intentional or not? I couldn't find any obvious clues in Java SOM's source to indicate anything either way.

[smarr]

Hmpf. You're too good at this...

The answer should really be nil, following all other Smalltalks I tested.

Blocks return the value of their last expression. Since there was no expression, there's no value.
At least that would be my interpretation of what the other Smalltalks do (GNU Smalltalk, Amber Smalltalk, Squeak 2, 5, and Pharo).

[ltratt]

My main skill here is ignorance! nil was what I was vaguely expecting, and it's easy to implement, so I won't complain!

[smarr]

Adding tests with #54