diff --git a/src/client.cc b/src/client.cc
index d1950985..bfa0099a 100644
--- a/src/client.cc
+++ b/src/client.cc
@@ -14,10 +14,10 @@ void draw_editor_ifn(Editor& editor)
         current_client->draw_window(*window);
 }
 
-String prompt(const String& text, Completer completer)
+String prompt(const String& text, const Context& context, Completer completer)
 {
     assert(current_client);
-    return current_client->prompt(text, completer);
+    return current_client->prompt(text, context, completer);
 }
 
 Key get_key()
diff --git a/src/client.hh b/src/client.hh
index b41de55b..3ec36620 100644
--- a/src/client.hh
+++ b/src/client.hh
@@ -10,6 +10,7 @@ namespace Kakoune
 class Editor;
 class Window;
 class String;
+class Context;
 
 class Client
 {
@@ -18,7 +19,7 @@ public:
 
     virtual void   draw_window(Window& window) = 0;
     virtual void   print_status(const String& status) = 0;
-    virtual String prompt(const String& prompt, Completer completer) = 0;
+    virtual String prompt(const String& prompt, const Context& context, Completer completer) = 0;
     virtual Key    get_key() = 0;
 };
 
@@ -27,7 +28,7 @@ struct prompt_aborted {};
 extern Client* current_client;
 
 void draw_editor_ifn(Editor& editor);
-String prompt(const String& text, Completer completer = complete_nothing);
+String prompt(const String& text, const Context& context, Completer completer = complete_nothing);
 Key get_key();
 void print_status(const String& status);
 
diff --git a/src/commands.cc b/src/commands.cc
index 66a05852..a926e67d 100644
--- a/src/commands.cc
+++ b/src/commands.cc
@@ -580,10 +580,10 @@ void set_option(OptionManager& option_manager, const CommandParameters& params,
 class RegisterRestorer
 {
 public:
-    RegisterRestorer(char name)
+    RegisterRestorer(char name, const Context& context)
        : m_name(name)
     {
-         memoryview<String> save = RegisterManager::instance()[name];
+         memoryview<String> save = RegisterManager::instance()[name].values(context);
          m_save = std::vector<String>(save.begin(), save.end());
     }
 
@@ -610,7 +610,7 @@ public:
         current_client = m_previous_client;
     }
 
-    String prompt(const String&, Completer)
+    String prompt(const String&, const Context&, Completer)
     {
         size_t begin = m_pos;
         while (m_pos < m_keys.size() and m_keys[m_pos].key != '\n')
@@ -654,8 +654,8 @@ void exec_keys(const KeyList& keys,
 {
     BatchClient batch_client(keys);
 
-    RegisterRestorer quote('"');
-    RegisterRestorer slash('/');
+    RegisterRestorer quote('"', context);
+    RegisterRestorer slash('/', context);
 
     Editor batch_editor(context.buffer());
     Editor& editor = context.has_window() ? static_cast<Editor&>(context.window())
@@ -717,7 +717,7 @@ void menu(const CommandParameters& params,
     }
     oss << "(empty cancels): ";
 
-    String choice = prompt(oss.str(), complete_nothing);
+    String choice = prompt(oss.str(), context, complete_nothing);
     int i = str_to_int(choice);
 
     if (i > 0 and i < (count / 2) + 1)
diff --git a/src/context.hh b/src/context.hh
index 8f4bc785..5a863c24 100644
--- a/src/context.hh
+++ b/src/context.hh
@@ -54,7 +54,6 @@ struct Context
     int numeric_param() const { return m_numeric_param; }
     void numeric_param(int param) { m_numeric_param = param; }
 
-
 public:
     safe_ptr<Editor> m_editor;
     safe_ptr<Buffer> m_buffer;
diff --git a/src/main.cc b/src/main.cc
index dc4e517a..b73efc5e 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -43,6 +43,7 @@ InsertSequence last_insert_sequence;
 
 template<typename GetKey, typename Redraw>
 void insert_sequence(IncrementalInserter& inserter,
+                     const Context& context,
                      GetKey get_key, Redraw redraw)
 {
     while (true)
@@ -66,7 +67,7 @@ void insert_sequence(IncrementalInserter& inserter,
             {
                 Key next_key = get_key();
                 if (next_key.modifiers == Key::Modifiers::None)
-                    inserter.insert(RegisterManager::instance()[next_key.key]);
+                    inserter.insert(RegisterManager::instance()[next_key.key].values(context));
                 break;
             }
             case 'm':
@@ -98,7 +99,7 @@ void do_insert(const Context& context)
     last_insert_sequence.keys.clear();
     IncrementalInserter inserter(context.editor(), mode);
     draw_editor_ifn(context.editor());
-    insert_sequence(inserter,
+    insert_sequence(inserter, context,
                     [&]() { Key key = get_key();
                             last_insert_sequence.keys.push_back(key);
                             return key; },
@@ -112,7 +113,7 @@ void do_repeat_insert(const Context& context)
 
     IncrementalInserter inserter(context.editor(), last_insert_sequence.mode);
     size_t index = 0;
-    insert_sequence(inserter,
+    insert_sequence(inserter, context,
                     [&]() { return last_insert_sequence.keys[index++]; },
                     [](){});
 }
@@ -168,9 +169,10 @@ void do_command(const Context& context)
 {
     try
     {
-        auto cmdline = prompt(":", std::bind(&CommandManager::complete,
-                                             &CommandManager::instance(),
-                                             _1, _2));
+        auto cmdline = prompt(":", context,
+                              std::bind(&CommandManager::complete,
+                                        &CommandManager::instance(),
+                                        _1, _2));
 
         CommandManager::instance().execute(cmdline, context);
     }
@@ -181,7 +183,7 @@ void do_pipe(const Context& context)
 {
     try
     {
-        auto cmdline = prompt("|", complete_nothing);
+        auto cmdline = prompt("|", context, complete_nothing);
 
         context.buffer().begin_undo_group();
         for (auto& sel : const_cast<const Editor&>(context.editor()).selections())
@@ -201,9 +203,9 @@ void do_search(const Context& context)
 {
     try
     {
-        String ex = prompt("/");
+        String ex = prompt("/", context);
         if (ex.empty())
-            ex = RegisterManager::instance()['/'][0];
+            ex = RegisterManager::instance()['/'].values(context)[0];
         else
             RegisterManager::instance()['/'] = ex;
 
@@ -215,7 +217,7 @@ void do_search(const Context& context)
 template<bool append>
 void do_search_next(const Context& context)
 {
-    const String& ex = RegisterManager::instance()['/'][0];
+    const String& ex = RegisterManager::instance()['/'].values(context)[0];
     if (not ex.empty())
         context.editor().select(std::bind(select_next_match, _1, ex), append);
     else
@@ -255,20 +257,20 @@ void do_paste(const Context& context)
     if (count == 0)
     {
         if (paste_mode == PasteMode::Before)
-            editor.insert(reg);
+            editor.insert(reg.values(context));
         else if (paste_mode == PasteMode::After)
-            editor.append(reg);
+            editor.append(reg.values(context));
         else if (paste_mode == PasteMode::Replace)
-            editor.replace(reg);
+            editor.replace(reg.values(context));
     }
     else
     {
         if (paste_mode == PasteMode::Before)
-            editor.insert(reg[count-1]);
+            editor.insert(reg.values(context)[count-1]);
         else if (paste_mode == PasteMode::After)
-            editor.append(reg[count-1]);
+            editor.append(reg.values(context)[count-1]);
         else if (paste_mode == PasteMode::Replace)
-            editor.replace(reg[count-1]);
+            editor.replace(reg.values(context)[count-1]);
     }
 }
 
@@ -276,7 +278,7 @@ void do_select_regex(const Context& context)
 {
     try
     {
-        String ex = prompt("select: ");
+        String ex = prompt("select: ", context);
         context.editor().multi_select(std::bind(select_all_matches, _1, ex));
     }
     catch (prompt_aborted&) {}
@@ -286,7 +288,7 @@ void do_split_regex(const Context& context)
 {
     try
     {
-        String ex = prompt("split: ");
+        String ex = prompt("split: ", context);
         context.editor().multi_select(std::bind(split_selection, _1, ex));
     }
     catch (prompt_aborted&) {}
@@ -468,9 +470,12 @@ int main(int argc, char* argv[])
     shell_manager.register_env_var("opt_.+",
                                    [](const String& name, const Context& context)
                                    { return context.option_manager()[name.substr(4)].as_string(); });
+    shell_manager.register_env_var("reg_.+",
+                                   [](const String& name, const Context& context)
+                                   { return RegisterManager::instance()[name[4]].values(context)[0]; });
 
-    register_manager.register_dynamic_register('%', [&]() { return std::vector<String>(1, main_context.buffer().name()); });
-    register_manager.register_dynamic_register('.', [&]() { return main_context.window().selections_content(); });
+    register_manager.register_dynamic_register('%', [&](const Context& context) { return std::vector<String>(1, context.buffer().name()); });
+    register_manager.register_dynamic_register('.', [&](const Context& context) { return context.editor().selections_content(); });
 
     register_commands();
     register_highlighters();
diff --git a/src/ncurses.cc b/src/ncurses.cc
index ad406d95..d85d6172 100644
--- a/src/ncurses.cc
+++ b/src/ncurses.cc
@@ -168,7 +168,7 @@ Key NCursesClient::get_key()
     return Key(modifiers, c);
 }
 
-String NCursesClient::prompt(const String& text, Completer completer)
+String NCursesClient::prompt(const String& text, const Context& context, Completer completer)
 {
     curs_set(2);
     auto restore_cursor = on_scope_end([]() { curs_set(0); });
@@ -249,7 +249,7 @@ String NCursesClient::prompt(const String& text, Completer completer)
         case CTRL('r'):
             {
                 c = getch();
-                String reg = RegisterManager::instance()[c][0];
+                String reg = RegisterManager::instance()[c].values(context)[0];
                 current_completion = -1;
                 result = result.substr(0, cursor_pos) + reg + result.substr(cursor_pos, String::npos);
                 cursor_pos += reg.length();
diff --git a/src/ncurses.hh b/src/ncurses.hh
index 8583240b..1a959ed0 100644
--- a/src/ncurses.hh
+++ b/src/ncurses.hh
@@ -18,7 +18,7 @@ public:
     void draw_window(Window& window);
     void print_status(const String& status);
 
-    String prompt(const String& prompt, Completer completer);
+    String prompt(const String& prompt, const Context& context, Completer completer);
     Key    get_key();
 };
 
diff --git a/src/rc/cpp.kak b/src/rc/cpp.kak
index f3e4dec9..3bfc5f73 100644
--- a/src/rc/cpp.kak
+++ b/src/rc/cpp.kak
@@ -23,7 +23,7 @@ hook global WinSetOption filetype=(?!cpp).* %{
 }
 
 hook global BufNew .*\.(h|hh|hpp|hxx|H) %{
-    exec ggi<c-r>%<ret><esc>ggxs\.<ret>c_<esc><space>A_INCLUDED<esc>xyppI#ifndef<space><esc>jI#define<space><esc>jI#endif<space>//<space><esc>O<esc>
+    exec ggi<c-r>%<ret><esc>ggxs\.<ret>c_<esc><space>A_INCLUDED<esc>ggxyppI#ifndef<space><esc>jI#define<space><esc>jI#endif<space>//<space><esc>O<esc>
 }
 
 def alt %{ edit %sh{
diff --git a/src/register.hh b/src/register.hh
index c90b7233..a38624d3 100644
--- a/src/register.hh
+++ b/src/register.hh
@@ -7,15 +7,15 @@
 namespace Kakoune
 {
 
+class Context;
+
 class Register
 {
 public:
     virtual ~Register() {}
     virtual Register& operator=(const memoryview<String>& values) = 0;
 
-    virtual const String& operator[](size_t index) = 0;
-
-    virtual operator memoryview<String>() = 0;
+    virtual memoryview<String> values(const Context& context) = 0;
 };
 
 }
diff --git a/src/register_manager.cc b/src/register_manager.cc
index 857f7324..e77510a1 100644
--- a/src/register_manager.cc
+++ b/src/register_manager.cc
@@ -17,17 +17,12 @@ public:
         return *this;
     }
 
-    const String& operator[](size_t index)
+    memoryview<String> values(const Context&)
     {
-        if (m_content.size() > index)
-            return m_content[index];
+        if (m_content.empty())
+            return memoryview<String>(ms_empty);
         else
-            return ms_empty;
-    }
-
-    operator memoryview<String>()
-    {
-        return memoryview<String>(m_content);
+            return memoryview<String>(m_content);
     }
 protected:
     std::vector<String> m_content;
@@ -50,16 +45,10 @@ public:
         throw runtime_error("this register is not assignable");
     }
 
-    const String& operator[](size_t index)
+    memoryview<String> values(const Context& context)
     {
-        m_content = m_function();
-        return StaticRegister::operator[](index);
-    }
-
-    operator memoryview<String>()
-    {
-        m_content = m_function();
-        return StaticRegister::operator memoryview<String>();
+        m_content = m_function(context);
+        return StaticRegister::values(context);
     }
 
 private:
diff --git a/src/register_manager.hh b/src/register_manager.hh
index 9f125b9f..e6fe7d94 100644
--- a/src/register_manager.hh
+++ b/src/register_manager.hh
@@ -12,7 +12,7 @@
 namespace Kakoune
 {
 
-typedef std::function<std::vector<String> ()> RegisterRetriever;
+typedef std::function<std::vector<String> (const Context&)> RegisterRetriever;
 
 class RegisterManager : public Singleton<RegisterManager>
 {