DB queries are a good analogy, especially if we qualify them as atomic operations. I’m hard-pressed to find a situation where procedural mutation-in-place make

DB queries are a good analogy, especially if we qualify them as atomic operations. I’m hard-pressed to find a situation where procedural mutation-in-place makes more logical sense than an atomic update of the whole list, so why not make atomic updates the default? It’s different if you’re working in lower-level code. I don’t intend to trivialize performance; the option to “go procedural” should be available. I just think it’s the wrong default. Operating systems and some kinds of Big Data need those perf boosts. But for your run-of-the-mill CRUD app, map/filter is both clearer and safer than a for loop. Strong language support encourages this both algorithmically and syntactically—unlike what Java did, which is what I originally replied to.