The null-coalescing discussion made me think about the current ternary "x = a if b else c" expression. In normal "if / else" clauses, the "else" is optional. I propose doing the same thing with ternary expressions (although I don't know what the result would be called, a "binary expression"?)

The idea would be to allow this syntax:

x = a if b

Which would be equivalent to:

x = a if b else x

I think this would be useful syntax. In particular, I see it being useful for default value checking, but can also be used to override the result of particular corner cases from functions or methods..