I was wondering which Vim setup Lars uses in his video, is this perhaps natively available when we use the nix-shell? In lecture two of the third cohort his vim suggests what I guess common used functions, what plugin is this?
I think we can't give exact definition of Lars' Vim configuration, but regarding the intelligent code completion, there are many Vim add-ons that achieve this. coc and Vim Intellisense are two examples.
If you're keen on modding your Vim configuration, you could also check Neovim, which is a fork that "strives to improve the extensibility and maintainability of Vim".
Take a look at this. After following this guide and setting up the plugins, you will need to
nix-shell inside plutus-apps, and then
cabal update and
cabal build inside the actual haskell code you are trying to use (as Lars explained in the first lecture). That's it, now you can use vim to open your file and, after some time, you will see some cool little colors.
By the way I suggest neovim, because with vim you don't have any idea of what's going on while haskell-language-server is still loading (also neovim is cooler)