I agree that the approach "everything is a bigint" plus optimizations where a fixed width int suffices would be nice from the semantic perspective. However, Ja

I agree that the approach "everything is a bigint" plus optimizations where a fixed width int suffices would be nice from the semantic perspective. However, Javascript has basically the "everything is a floating point number" approach, and bigints would be hard to fit into that (do you want bigfloat as well? do you want to reproduce float arithmetic imprecision, or be precise? Etc.) However, bigint could internally use just one fixed width number when possible as an optimization - although the current implementation doesn't seem to do this.