No, operator overloading isn't in the language spec, with reason. I think numerical computing libs like LAPACK, if ported to JS, will probably require a wrapper around 64-bit floats (a la BigDecimal) and math operators that are really function calls. The plan has been to look into transpiling from fortran to asm.js although my personal feeling is it would be better just to use the C API and compile a module that statically links in the necessary libs. They'll figure it out...