Set is a well defined container for unique values. It's much clearer what it is than some non-existent .distinct() function with no definition and unclear retur

Set is a well defined container for unique values. It's much clearer what it is than some non-existent .distinct() function with no definition and unclear return value. Procedural code in JS doesn't say how you want something done any more closely than the functional style variant. for-of is far more generic than .map/.filter() since .map() only works on Array shaped objects, and for-of works on all iterables, even generators, async generators, etc. In any case you're not saying how the iteration will happen with for-of, you're just saying that you want it. Implementation of Set is also the choice of a language runtime. You're just stating what type of container you want. Sometimes functional style may be more readable, sometimes procedural style may.