I believe a big part of the famous Javascript semantics can be emulated in Scala with a library.
Once upon a time I wrote a toy Android app with Scaloid, and tried to use some on-device print-debugging. toast("foo") worked just fine. toast(42) crashed at runtime. Turns out Scaloid offers an implicit conversion from Int to CharSequence, and it even doesn't turn 42 into anything like "42". I'm not kidding [1]. In Android you normally have "resource identifiers" as integers with no compile-time type information, and then at runtime you never use these as actual numbers, instead you every single time pass them to some function like getText or getDrawable. Sound like the perfect case for implicit conversion, right?