This is function operating on values with slightly relaxed type checks. Default mode in dynamic languages: let list_add = (n, prev, next) => { prev[1

This is function operating on values with slightly relaxed type checks. Default mode in dynamic languages: let list_add = (n, prev, next) => { prev[1] = n n[1] = next n[0] = prev if (next) next[0] = n } foo = [null, null, 3] bar = [null, null, 5] list_add(bar, foo, null) Looks a bit cooler with C structs names as offset. Inheritance would be building container hierarchy on top of that. Could be brittle in any language.