experimental/vim-vam-pathogen-vimrc-support

This patch implements derving a .vimrc from vim-plugins.nix loading those
plugins by either Pathogen or VAM (VAM seems to be slightly faster and is much
more powerful).

Example:

  environment.systemPackages = [
   # default plain vim
   vim_configurable

   # vim which get's called vim-with-addon-nix
   (vim_configurable.customize {
      name = "vim-with-addon-nix";
     vimrcConfig.vam.pluginDictionaries = [{name = "vim-addon-nix"; }];
   })
  ];

This way you can provide an "enhanced Vim" and a standard Vim.

Details about what this commit changes:
1) provide a new toplevel name vimrc which
  * provides a way to build up a .vimrc using either pathogen or VAM (knowing about plugin dependencies by name)
  * can enhance vim to support. vim.customize { name = "name-user"; vam.pluginDictionaries and/or pathogen.pluginNames = .. }
  * introduce rtp names for each vim plugin pointing to the runtimepath path
  * suggest naming to be the same as vim-pi so that VAM's dependencies work
  * derive some packages as example from vim-pi using VAM's new autoload/nix.vim
    supporting simple dependencies
  * test case for vim-addon-nix for VAM/pathogen

2) enhance vim_configurable to support .customize

3) update many plugins by using VAM's implementation not rewriting those which
  * vim-pi doesn't know about the git source yet (TODO: make vim-pi be aware of
    those)
  * have special build code

This commit partially conflicts with commits done by Bjørn Forsman starting by
37f961628b, eg the one using lower case attr and pkg names, because they don't
match vim-pi (eg YouCompleteMe). Rather than resolving the conflict this just
adds aliases so that both names can be used

pkgs/misc/vim-plugins/vimrc.nix

@@ -0,0 +1,203 @@
+{stdenv, vimPlugins, vim_configurable, buildEnv, writeText, writeScriptBin}:
+
+  /* usage example::
+     let vimrcConfig = {
+
+       # If you like pathogen use such
+       pathogen.knownPlugins = vimPlugins; # optional
+       pathogen.pluginNames = ["vim-addon-nix"];
+
+       # If you like VAM use such:
+       vam.knownPlugins = vimPlugins; # optional
+       vam.pluginDictionaries = [
+         # load always
+         { name = "youcompleteme"; }
+         { names = ["youcompleteme" "foo"]; }
+         # only load when opening a .php file
+         { name = "phpCompletion"; ft_regex = "^php\$"; }
+         { name = "phpCompletion"; filename_regex = "^.php\$"; }
+
+         # provide plugin which can be loaded manually:
+         { name = "phpCompletion"; tag = "lazy"; }
+       ];
+
+       # if you like NeoBundle or Vundle provide an implementation
+
+       # add custom .vimrc lines like this:
+       customRC = ''
+         set hidden
+       '';
+     };
+     in vim_configurable.customize { name = "vim-with-plugins"; inherit vimrcConfig; };
+
+  */
+
+let
+  inherit (stdenv) lib;
+
+  findDependenciesRecursively = {knownPlugins, names}:
+
+    let depsOf = name: (builtins.getAttr name knownPlugins).dependencies or [];
+
+        recurseNames = path: names: lib.concatMap (name: recurse ([name]++path)) names;
+
+        recurse = path:
+          let name = builtins.head path;
+          in if builtins.elem name (builtins.tail path)
+            then throw "recursive vim dependencies"
+            else [name] ++ recurseNames path (depsOf name);
+
+    in lib.uniqList { inputList = recurseNames [] names; };
+
+  vimrcFile = {
+    vam ? null,
+    pathogen ? null,
+    customRC ? ""
+  }:
+
+    let
+      /* pathogen mostly can set &rtp at startup time. Its used very commonly.
+      */
+      pathogenImpl = lib.optionalString (pathogen != null)
+      (let
+        knownPlugins = pathogen.knownPlugins or vimPlugins;
+
+        plugins = map (name: knownPlugins.${name}) (findDependenciesRecursively { inherit knownPlugins; names = pathogen.pluginNames; });
+
+        pluginsEnv = buildEnv {
+          name = "pathogen-plugin-env";
+          paths = map (x: "${x}/${vimPlugins.rtpPath}") plugins;
+        };
+      in
+      ''
+        let &rtp.=(empty(&rtp)?"":',')."${vimPlugins.pathogen.rtp}"
+        execute pathogen#infect('${pluginsEnv}/{}')
+      '');
+
+      /*
+       vim-addon-manager = VAM
+
+       * maps names to plugin location
+
+       * manipulates &rtp at startup time
+         or when Vim has been running for a while
+
+       * can activate plugins laziy (eg when loading a specific filetype)
+
+       * knows about vim plugin dependencies (addon-info.json files)
+
+       * still is minimalistic (only loads one file), the "check out" code it also
+         has only gets loaded when a plugin is requested which is not found on disk
+         yet
+
+      */
+      vamImpl = lib.optionalString (vam != null)
+      (let
+        knownPlugins = vam.knownPlugins or vimPlugins;
+
+        toNames = x:
+            if builtins.isString x then [x]
+            else (lib.optional (x ? name) x.name)
+                  ++ (x.names or []);
+
+        names = findDependenciesRecursively { inherit knownPlugins; names = lib.concatMap toNames vam.pluginDictionaries; };
+
+        # Vim almost reads JSON, so eventually JSON support should be added to Nix
+        # TODO: proper quoting
+        toNix = x:
+          if (builtins.isString x) then "'${x}'"
+          else if builtins.isAttrs x && builtins ? out then toNix "${x}" # a derivation
+          else if builtins.isAttrs x then "{${lib.concatStringsSep ", " (lib.mapAttrsToList (n: v: "${toNix n}: ${toNix v}") x)}}"
+          else if builtins.isList x then "[${lib.concatMapStringsSep ", " toNix x}]"
+          else throw "turning ${lib.showVal x} into a VimL thing not implemented yet";
+
+      in assert builtins.hasAttr "vim-addon-manager" knownPlugins;
+      ''
+        let g:nix_plugin_locations = {}
+        ${lib.concatMapStrings (name: ''
+          let g:nix_plugin_locations['${name}'] = "${knownPlugins.${name}.rtp}"
+        '') names}
+        let g:nix_plugin_locations['vim-addon-manager'] = "${vimPlugins."vim-addon-manager".rtp}"
+
+        let g:vim_addon_manager = {}
+
+        if exists('g:nix_plugin_locations')
+          " nix managed config
+
+          " override default function making VAM aware of plugin locations:
+          fun! NixPluginLocation(name)
+            let path = get(g:nix_plugin_locations, a:name, "")
+            return path == "" ? vam#DefaultPluginDirFromName(a:name) : path
+          endfun
+          let g:vim_addon_manager.plugin_dir_by_name = 'NixPluginLocation'
+          " tell Vim about VAM:
+          let &rtp.=(empty(&rtp)?"":','). g:nix_plugin_locations['vim-addon-manager']
+        else
+          " standalone config
+
+          let &rtp.=(empty(&rtp)?"":',').c.plugin_root_dir.'/vim-addon-manager'
+          if !isdirectory(c.plugin_root_dir.'/vim-addon-manager/autoload')
+            " checkout VAM
+            execute '!git clone --depth=1 git://github.com/MarcWeber/vim-addon-manager '
+                \       shellescape(c.plugin_root_dir.'/vim-addon-manager', 1)
+          endif
+        endif
+
+        " tell vam about which plugins to load when:
+        let l = []
+        ${lib.concatMapStrings (p: "call add(l, ${toNix p})\n") vam.pluginDictionaries}
+        call vam#Scripts(l, {})
+      '');
+
+      # somebody else could provide these implementations
+      vundleImpl = "";
+
+      neobundleImpl = "";
+
+
+  in writeText "vimrc" ''
+  " minimal setup, generated by NIX
+  set nocompatible
+  filetype indent plugin on | syn on
+
+  ${vamImpl}
+  ${pathogenImpl}
+  ${vundleImpl}
+  ${neobundleImpl}
+
+  ${customRC}
+  '';
+
+in
+
+rec {
+  inherit vimrcFile;
+
+  # shell script with custom name passing [-u vimrc] [-U gvimrc] to vim
+  vimWithRC = {vimExecutable, name ? null, vimrcFile ? null, gvimrcFile ? null}:
+    let rcOption = o: file: stdenv.lib.optionalString (file != null) "-${o} ${file}";
+    in writeScriptBin (if name == null then "vim" else name) ''
+      #!/bin/sh
+      exec ${vimExecutable} ${rcOption "u" vimrcFile} ${rcOption "U" gvimrcFile} "$@"
+      '';
+
+  # add a customize option to a vim derivation
+  makeCustomizable = vim: vim // {
+    customize = {name, vimrcConfig}: vimWithRC {
+      vimExecutable = "${vim}/bin/vim";
+      inherit name;
+      vimrcFile = vimrcFile vimrcConfig;
+    };
+  };
+
+  # test cases:
+  test_vim_with_vim_addon_nix_using_vam = vim_configurable.customize {
+    name = "vim-with-vim-addon-nix-using-vam";
+    vimrcConfig.vam.pluginDictionaries = [{name = "vim-addon-nix"; }];
+  };
+
+  test_vim_with_vim_addon_nix_using_pathogen = vim_configurable.customize {
+    name = "vim-with-vim-addon-nix-using-pathogen";
+    vimrcConfig.pathogen.pluginNames = [ "vim-addon-nix" ];
+  };
+}

pkgs/top-level/all-packages.nix

@@ -10597,7 +10597,7 @@ let
 
   vimHugeX = vim_configurable;
 
-  vim_configurable = callPackage ../applications/editors/vim/configurable.nix {
+  vim_configurable = vimrc.makeCustomizable (callPackage ../applications/editors/vim/configurable.nix {
     inherit (pkgs) fetchurl fetchhg stdenv ncurses pkgconfig gettext
       composableDerivation lib config glib gtk python perl tcl ruby;
     inherit (pkgs.xlibs) libX11 libXext libSM libXpm libXt libXaw libXau libXmu
@@ -10612,7 +10612,7 @@ let
 
     # so that we can use gccApple if we're building on darwin
     inherit stdenvAdapters gccApple;
-  };
+  });
 
   vimNox = lowPrio (vim_configurable.override { source = "vim-nox"; });
 
@@ -12305,6 +12305,8 @@ let
 
   viewnior = callPackage ../applications/graphics/viewnior { };
 
+  vimrc = callPackage ../misc/vim-plugins/vimrc.nix { inherit writeText; };
+
   vimPlugins = recurseIntoAttrs (callPackage ../misc/vim-plugins { });
 
   vimprobable2 = callPackage ../applications/networking/browsers/vimprobable2 {