Else statement

[JacquelineCasey]

We have if statements expressions, now time for else blocks.

Be delicate with the syntax here - we want else-if for free of course.

Also, make sure that the type of an if-else expression is computed correctly.

Note - may require better type unification - easier said than done...

[JacquelineCasey]

One test should be an expressional if.

...
val c = a + if ... { ... } else { ... } + b

[JacquelineCasey]

Done. Surprisingly easy.