Pattern matching will only get you so far without static analysis, though? For example, if I have a function that returns {foo}, and I change it to return {foo

Pattern matching will only get you so far without static analysis, though? For example, if I have a function that returns {foo}, and I change it to return {foo, bar}, then a pattern match on its return value that does {Foo} -> ... will fail at runtime, and the compiler won't pick it up, right? In a statically type language (such as Go), changing the number (or type) of return values will result in compilation errors until all callers have been updated.