Neovim is the best Haskell editor, thanks in large part to Marc Jakobi’s excellent haskell-tools plugin.
If you configure your Neovim with Nix you can use this snippet to get started quickly.
{ pkgs, ... }:
{
programs.neovim.plugins = with pkgs.unstable.vimPlugins; [
haskell-tools-nvim
];
xdg.configFile."nvim/ftplugin/haskell.lua".text = ''
local ht = require('haskell-tools')
local bufnr = vim.api.nvim_get_current_buf()
local opts = { noremap = true, silent = true, buffer = bufnr, }
ht.lsp.start()
'';
}