Small correction, but it's optimized to int31 by all the current engines with the last bit used for tagging. BigInt is now available on Firefox and Chrome (wit

Small correction, but it's optimized to int31 by all the current engines with the last bit used for tagging. BigInt is now available on Firefox and Chrome (with JSC/Safari support in the works). That gives arbitrarily-large integers (with the JIT deciding the best size.