On Apr 17, 2011, at 7:52 AM, Adam Stankiewicz wrote: > Hello everyone, > > My idea is to disallow overwriting of === operator, and make 'compare' > operator implement == instead. Why? > > 1. === means for me that two variables have reference to the same > object, so there is no point of overwriting it. Many programmers would > be confused.
The reason === comes up with value types/proxies is the goal of supporting decimal and other number types, where 1.1m === something_computing_fresh_1_1m() must be true. Decimal in IEEE754r also wants NaNm !== NaNm, and -0m === 0m. > 2. == always caused problems, above change gives it opportunity to > return to grace. I'm always in favor of adding ways for that which fell from grace to be redeemed over time, by developer choice, without breaking the old form if possible. This is a recurrent theme. > You don't know if they are the same object? Use ===. Don't know if > these objects are the same, but only in eyes of programmer? Use ==. > Think about == or < as semantical operators, and === as hard-cored > is-the-same-object function. The problem is objects in JS are reference types currently. Value types or proxies would be objects that, by virtue of being shallowly frozen, say, could be compared by reference or property values. This needs care in spec'ing since the shallow vs. deep freezing may not cover value types with deeper structures that nevertheless want to be compared by value. Deep comparison is possible of course, just more work. /be _______________________________________________ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss
