The Flow core type system is sound: https://dl.acm.org/citation.cfm?doid=3152284.3133872 https://dl.acm.org/citation.cfm?doid=3152284.3133872, although there ar

The Flow core type system is sound: https://dl.acm.org/citation.cfm?doid=3152284.3133872 https://dl.acm.org/citation.cfm?doid=3152284.3133872, although there are unfortunately some known unsoundnesses in the actual type system. Does Dart suffer from the same? Hack does check type hints at runtime, so it's "sound" in the same sense as Java might be. Is this the same sense in which Dart is sound? > the type system is sound and checked at runtime in cases where it can be proven statically safe I didn't understand this. If the code is statically proven safe, why would you need runtime checks?