Setfield.jl

> if you choose immutable structs, your interface for users is EXTREMELY annoying. For example, if they want to update `x` from `1` to be `2` That's the whole point of immutability that you can't "just update". I fail to see how obscure magical updates on immutable (?) structs like advertised in [1] or [2] e.g. using Accessors @set obj.a.b.c = d are beneficial. Note that there is _zero_ explanation on the front page of what the above snippet does, how to use it and what actually happens under the hood. One example of why I personally don't have much trust in JuliaLand. Scala has `x.copy(field=newval)` for its (immutable) case classes. Note how clear it is that one is making a copy. Lenses are also outside of the stdlib (e.g. [3]). [1] https://github.com/JuliaObjects/Accessors.jl [2] https://github.com/jw3126/Setfield.jl [3] https://w

Some points have simple answers: * Support for using @copied s.x = 1 where s is an immutable struct. I believe the standard package for this is this: https://github.com/jw3126/Setfield.jl#usage * Currently macros have to be valid Julia code, There are two kinds of macros, and it sounds like you want `macro foo_str(x)` which accepts anything. But the tradeoff is that you have to parse it, rather than getting an expression tree. https://docs.julialang.org/en/v1/manual/metaprogramming/#met...