Nix Should Focus on the Static

Cause # My Firefox on NixOS met a problem: everytime the home environment is rebuilt, the ~/.mozilla folder must be removed for home-manager to set up configs. Therefore, all stored information, including those that cannot be generated from Nix like history, passwords, etc. are lost. Blaming Nix for overriding those information is almost the sudden reaction. However, home-manager is just doing its job: reproduce the same thing. The problem is that we’re requiring something that should not be considered part of reproducibility - which is exactly the opposite.

Easy Way Understanding Fix

Introduction # Fix point of $f: A \rightarrow A$ is $x \in A$ such that $f(x)=x$. fix in haskell is used to find the (least) fix point for a function, which has the type (a -> a) -> a. It’s also widely used as a helper function for writing recursive functions. But how, and why? Fix and Recursive Functions # Generalise Recursive Function # We can first describe recursive functions without using the word “recursive”.