This is potentially deprecated, since as of Nix 2.21 pretty printing is builtin
A fork simply for the purpose of adding pretty printing to the Repl (:pp). It is based on nixfmt-flib, a fork of nixfmt that adds FFI and some (not so pretty) changes to make sure no functionality is lost in the Repl such as color codes and unshowable expressions such as «derivation ...».
The default package has been changed to:
writeScriptBin "nix-repl" ''
${nix} repl $@
'';This fork also enables ReplFlake by default (C/P from this commit). So this should be a streight replacement to the normal nix repl
Nix already has a configuration flag that allows building with readline instead of editline, this fork enables that by default, meaning that you can get vi keybindings by adding set editing-mode vi to ~/.inputrc if you desire, or toggle it while in the repl via C-M-j (Ctrl-Alt-j).
In theory you should be able to use vi mode on nix with editline by adding bind -v to ~/.editrc, however I was not able to reproduce that.
Obviously this is super inefficient, as in you download and build a whole different clone just to use nix repl, but for me it is simpler to use it like this vs figuring out how to decouple the repl from the rest.