[rurban]

With types you get more compile-time checks - safer code, better documentation, and the possibility to improve runtime performance and ffi. With a guaranteed int you don't need to check for bignum overflows, and you can avoid all runtime type checks. A typed ffi struct can be used as is for the ffi, raw data. strings are guaranteed to be 0 delimited.

In certain basic blocks typed ints or floats can be unboxed, if they will not escape. This is what php7 made 2x faster. the stack will get much leaner. simple arithmetic ops can be inlined, using native variants. ops with typed vars cannot be overridden.