Why "?T" instead of "T?"?

# John Cowan (19 years ago)

With conditional types gone, is there any reason not to use the clearer "T?" for a nullable type? It's compatible with C# and with the "T!" syntax.

# Jeff Dyer (19 years ago)

Ah, good catch. Until recently there was a syntactic ambiguity with conditional expressions. But with the recent introduction of type expressions that is no longer the case; T? and T?x:y no longer co-occur in the same syntactic context. I'll propose to the working group that we restore symmetry between T! and T?. Cool!