modules: start breaking down core modules; simplify tree structure

modules/plugins/ui/smartcolumn/config.nix

@@ -0,0 +1,26 @@
+{
+  pkgs,
+  config,
+  lib,
+  ...
+}: let
+  inherit (lib) mkIf nvim concatStringsSep;
+
+  cfg = config.vim.ui.smartcolumn;
+in {
+  config = mkIf cfg.enable {
+    vim.startPlugins = [
+      "smartcolumn"
+    ];
+
+    vim.luaConfigRC.smartcolumn = nvim.dag.entryAnywhere ''
+      require("smartcolumn").setup({
+        colorcolumn = "${toString cfg.showColumnAt}",
+        -- { "help", "text", "markdown", "NvimTree", "alpha"},
+        disabled_filetypes = { ${concatStringsSep ", " (map (x: "\"" + x + "\"") cfg.disabledFiletypes)} },
+        custom_colorcolumn = ${nvim.lua.attrsetToLuaTable cfg.columnAt.languages},
+        scope = "file",
+      })
+    '';
+  };
+}

modules/plugins/ui/smartcolumn/default.nix

@@ -0,0 +1,6 @@
+_: {
+  imports = [
+    ./smartcolumn.nix
+    ./config.nix
+  ];
+}

modules/plugins/ui/smartcolumn/smartcolumn.nix

@@ -0,0 +1,37 @@
+{lib, ...}: let
+  inherit (lib) mkEnableOption mkOption types literalExpression;
+in {
+  options.vim.ui.smartcolumn = {
+    enable = mkEnableOption "line length indicator";
+
+    showColumnAt = mkOption {
+      type = types.nullOr types.int;
+      default = 120;
+      description = "The position at which the column will be displayed. Set to null to disable";
+    };
+
+    disabledFiletypes = mkOption {
+      type = types.listOf types.str;
+      default = ["help" "text" "markdown" "NvimTree" "alpha"];
+      description = "The filetypes smartcolumn will be disabled for.";
+    };
+
+    columnAt = {
+      languages = mkOption {
+        description = "The position at which smart column should be displayed for each individual buffer type";
+        type = types.submodule {
+          freeformType = with types; attrsOf (either int (listOf int));
+        };
+
+        example = literalExpression ''
+          vim.ui.smartcolumn.columnAt.languages = {
+            nix = 110;
+            ruby = 120;
+            java = 130;
+            go = [90 130];
+          };
+        '';
+      };
+    };
+  };
+}