Nix repl and readline

[abathur]

I don’t have any firsthand knowledge here; just looking through history and pulling threads…

• It looks like readline was replaced with linenoise in 2017 due to a license issue and to reduce the footprint by avoiding ncurses:

  Replace readline by linenoise · NixOS/nix@c5f23f1 · GitHub

• linenoise appears to have had its own licensing issue that resulted in editline replacing it within a year:

  • linenoise embeds non-free ConvertUTF{.cpp,.h} · Issue #2014 · NixOS/nix · GitHub
  • use editline instead of linenoise(-ng) by dtzWill · Pull Request #2228 · NixOS/nix · GitHub

• It looks like very basic support for building w/ readline was readded not long after, but that there’s some reluctance to actually maintain two sets of code there:

  • repl: give user the choice between libeditline and libreadline by KaiHa · Pull Request #2551 · NixOS/nix · GitHub
  • Kaiha/pr/readline by KaiHa · Pull Request #3196 · NixOS/nix · GitHub