treewide: rewrite autocompletion module and related stuff (#404)

* modules/completion: rewrite

* treewide: remove vsnip, add luasnip

* nvim-cmp: add default sorting

* nvim-cmp: load after luasnip

* lib: fix docs for mergelessListOf

* docs: add changelog entires for rewrite

* deprecations: add rewrite deprecations

* nvim-cmp: clarify in format description

* docs: fix option reference in release notes

* treewide: remove reduant `// {default = false;}`s

* luasnip: add missing `{option}` for option reference

* deprecations: add entry for vsnip

* nvim-autopairs: use multiline string

* nvim-dap: use outer attribute

lib/attrsets.nix

@@ -0,0 +1,5 @@
+{lib}: let
+  inherit (builtins) listToAttrs;
+in {
+  mapListToAttrs = f: list: listToAttrs (map f list);
+}

lib/default.nix

@@ -10,6 +10,7 @@
   dag = import ./dag.nix {inherit lib;};
   languages = import ./languages.nix {inherit lib;};
   lists = import ./lists.nix {inherit lib;};
+  attrsets = import ./attrsets.nix {inherit lib;};
   lua = import ./lua.nix {inherit lib;};
   neovimConfiguration = import ../modules {inherit inputs lib;};
 }

lib/languages.nix

@@ -2,8 +2,8 @@
 {lib}: let
   inherit (builtins) isString getAttr;
   inherit (lib.options) mkOption;
-  inherit (lib.attrsets) listToAttrs;
   inherit (lib.types) bool;
+  inherit (lib.nvim.attrsets) mapListToAttrs;
 in {
   # Converts a boolean to a yes/no string. This is used in lots of
   # configuration formats.
@@ -12,21 +12,21 @@ in {
     config,
     diagnosticsProviders,
   }:
-    listToAttrs
-    (map (v: let
-        type =
-          if isString v
-          then v
-          else getAttr v.type;
-        package =
-          if isString v
-          then diagnosticsProviders.${type}.package
-          else v.package;
-      in {
-        name = "${lang}-diagnostics-${type}";
-        value = diagnosticsProviders.${type}.nullConfig package;
-      })
-      config);
+    mapListToAttrs
+    (v: let
+      type =
+        if isString v
+        then v
+        else getAttr v.type;
+      package =
+        if isString v
+        then diagnosticsProviders.${type}.package
+        else v.package;
+    in {
+      name = "${lang}-diagnostics-${type}";
+      value = diagnosticsProviders.${type}.nullConfig package;
+    })
+    config;
 
   mkEnable = desc:
     mkOption {

lib/types/custom.nix

@@ -1,7 +1,7 @@
 {lib}: let
-  inherit (lib) isStringLike showOption showFiles getFiles mergeOneOption mergeEqualOption mkOptionType;
-  inherit (lib.strings) isString;
-  inherit (lib.types) anything attrsOf;
+  inherit (lib.options) showOption showFiles getFiles mergeOneOption mergeEqualOption;
+  inherit (lib.strings) isString isStringLike;
+  inherit (lib.types) anything attrsOf listOf mkOptionType;
   inherit (lib.nvim.types) anythingConcatLists;
   inherit (builtins) typeOf isAttrs any head concatLists stringLength match;
 in {
@@ -52,6 +52,16 @@ in {
         (mergeFunctions.${commonType} or mergeEqualOption) loc defs;
     };
 
+  mergelessListOf = elemType: let
+    super = listOf elemType;
+  in
+    super
+    // {
+      name = "mergelessListOf";
+      description = "mergeless ${super.description}";
+      merge = mergeEqualOption;
+    };
+
   char = mkOptionType {
     name = "char";
     description = "character";

lib/types/default.nix

@@ -6,10 +6,10 @@
   typesDag = import ./dag.nix {inherit lib;};
   typesPlugin = import ./plugins.nix {inherit inputs lib;};
   typesLanguage = import ./languages.nix {inherit lib;};
-  typesTypes = import ./types.nix {inherit lib;};
+  customTypes = import ./custom.nix {inherit lib;};
 in {
   inherit (typesDag) dagOf;
   inherit (typesPlugin) pluginsOpt extraPluginType mkPluginSetupOption luaInline pluginType borderType;
   inherit (typesLanguage) diagnostics mkGrammarOption;
-  inherit (typesTypes) anythingConcatLists char hexColor;
+  inherit (customTypes) anythingConcatLists char hexColor mergelessListOf;
 }