> Julia is fastest with immutable structures--why provide a built-in syntax for complex assignment to mutable types, but then relegate lenses to a library that only FP aficionados will use?
This is not really accurate. Performance in Julia is heavily organized around mutability, in particular for arrays. The main reason Julia does not fully embrace immutability for everything is, simply, performance.
This is not really accurate. Performance in Julia is heavily organized around mutability, in particular for arrays. The main reason Julia does not fully embrace immutability for everything is, simply, performance.