Optional typing is one of my favorite features of groovy. Explicit typing also helps show where code needs to be explicitly performant and of course where type

Optional typing is one of my favorite features of groovy. Explicit typing also helps show where code needs to be explicitly performant and of course where type strictness is valuable. I'm assuming of course that types in js flavors has performance advantages a la asm.js, but admittedly I haven't tracked JavaScript evolution that closely. If it isn't typed then that helps clue the programmer that looser dynamic techniques being used.