Remix clone Hacker News

It's unlikely because people don't get why jump through so many hoops when you can

  new = copy(old)
  new.foo.bar.baz = new_baz
  return new

It won't come out of Haskell because it's uniquely a solution to a specific Haskell problem. Mutating a fresh copy through a "lens" when you have `=` is a level of geekage that cannot become mainstream.

▲ kqr 9 days ago | parent | next [-]

This is a common misconception. Lenses (or more generally optics) are not limited to targeting single fields. They can target composites, alternatives, etc. They go way beyond a normal accessor dot and can do stuff that cannot be done in mainstream languages.

Some of the other ideas from lenses are becoming mainstream, like the .? conditional accessor in e.g. C# and EcmaScript.

	▲	wruza 9 days ago \| parent [-]
		They don't surpass Turing Machine level, so I'm not convinced. The idea of ?. was there since the beginning of times. You don't have to dig deep to realize that (x ? x.y : nil) and (x ? x : y) sucks. Even gnu C had (x ?: y) for quite a while. It's just that the designers of to-become-mainstream languages all start with the same "density" and ignore the damn obvious, and then rather than fixing it, chew on the same dilemmas they all inevitably introduce. I sometimes wonder if they have written regular code at all or started inventing languages right after school.

▲ yen223 9 days ago | parent | prev [-]

This comment proves my point about how "all the Haskell" hinders mainstream adoption of a thing. It's very easy for folks to miss the point of the thing!

Lenses and more generally optics are a lot more powerful than just dot-accessors. They are closer in spirit to XPath or jq, except that they are general enough to work on most data structures, not just XML or Json.

	▲	wruza 8 days ago \| parent [-]
		It doesn't. "All the haskell" is your protective decoy against "it's not that useful when you're not chained to the wall". Show me a lens with a bunch of other fp tricks and I'll write dumb inline code for it that does that same thing, but without twisting anyones brain or trying to not miss its thin point.