flake.nix

@@ -256,10 +256,12 @@
             neoformat = { };
             hop-nvim = { };
             telescope-nvim = { };
+            nvim-cmp = { };
           };
 
           plugins = with prev.nix2lua.lib; {
             editorconfig-nvim = true;
+            lualine-lsp-progress = true;
             lualine-nvim = pipe1
               (require "lualine")
               (call "setup" {

lib/vim.nix

@@ -3,6 +3,9 @@
 with nix2lua.lib;
 {
   g = varName: expr: set "vim.g.${varName}" expr;
+  opt = varName: expr: set "vim.opt.${varName}" expr;
+
+  fn' = fnName: args: call "vim.fn[\"${fnName}\"]" args;
   fn.isdirectory = file: call1 "vim.fn.isdirectory" (var file);
 
   cmd' = expr: call1 "vim.cmd" expr;

modules/nvim-cmp.nix

@@ -0,0 +1,41 @@
+{ nix2lua, vim, ... }:
+
+with nix2lua.lib;
+
+let
+  defaultCmpKeymaps = {
+    "<C-b>" = call "cmp.mapping.scroll_docs" (- 4);
+    "<C-d>" = call "cmp.mapping.scroll_docs" 4;
+    "<C-Space>" = call0 "cmp.mapping.complete";
+    "<C-e>" = call0 "cmp.mapping.abort";
+    "<CR>" = call "cmp.mapping.confirm" { select = true; };
+  };
+in
+
+{ cmpKeymaps ? defaultCmpKeymaps
+, extraCmpKeymaps ? { }
+, cmpSources ? { }
+}:
+
+{
+  luasnip = true;
+  cmp-luasnip = true;
+
+  nvim-cmp = [
+    (vim.opt "completeopt" [ "menu" "menuone" "noselect" ])
+
+    (local (set "cmp" (require "cmp")))
+
+    (pipe1
+      (var "cmp")
+      (call "setup" {
+        snippet.exand = lambda [ "args" ]
+          (pipe1 (require "luasnip") (call "lsp_expand" (var "args")));
+
+        mapping = call "cmp.mapping.preset.insert" (cmpKeymaps // extraCmpKeymaps);
+
+        sources = call "cmp.config.sources" cmpSources;
+      })
+    )
+  ];
+}