I think for FP it should be added, that the state is explicit and has a clear owner. Eventually someone has to replace the old value with the new value in the c

I think for FP it should be added, that the state is explicit and has a clear owner. Eventually someone has to replace the old value with the new value in the call chain What's really interesting is Rust arrived at a similar destination, I assume as a natural byproduct of pushing for memory+thread safety. State isn't discouraged, but you get explicit owner(s) of data who lend it out to others who are readonly by default, and explicit when they will modify the reference you gave them.