Add scoped aliases

aliases are now stored in window, buffer, or globally.

README.asciidoc

@@ -988,6 +988,27 @@ Some helper commands can be used to define composite commands:
 Note that these commands are available in interactive command mode, but are
 not that useful in this context.
 
+Aliases
+-------
+
+With +:alias+ commands can be given additional names. aliases are scoped, so
+that an alias can refer to one command for a buffer, and to another for another
+buffer.
+
+--------------------------------
+:alias <scope> <alias> <command>
+--------------------------------
+
+with +<scope>+ being +global+, +buffer+ or +window+, will define +<alias>+ as
+an alias for +<command>+
+
+-------------------------------------
+:unalias <scope> <alias> [<expected>]
+-------------------------------------
+
+Will remove the given alias in the given scope. If +<expected>+ is specified
+the alias will only be removed if its current value is +<expected>+.
+
 FIFO Buffer
 -----------
 

src/alias_registry.cc

@@ -0,0 +1,48 @@
+#include "alias_registry.hh"
+
+#include "command_manager.hh"
+
+namespace Kakoune
+{
+
+void AliasRegistry::add_alias(String alias, String command)
+{
+    kak_assert(not alias.empty());
+    kak_assert(CommandManager::instance().command_defined(command));
+    m_aliases[alias] = std::move(command);
+}
+
+void AliasRegistry::remove_alias(const String& alias)
+{
+    auto it = m_aliases.find(alias);
+    if (it != m_aliases.end())
+        m_aliases.erase(it);
+}
+
+StringView AliasRegistry::operator[](const String& alias) const
+{
+    auto it = m_aliases.find(alias);
+    if (it != m_aliases.end())
+        return it->second;
+    else if (m_parent)
+        return (*m_parent)[alias];
+    else
+        return StringView{};
+}
+
+std::vector<StringView> AliasRegistry::aliases_for(StringView command) const
+{
+    std::vector<StringView> res;
+    if (m_parent)
+        res = m_parent->aliases_for(command);
+
+    for (auto& alias : m_aliases)
+    {
+        if (alias.second == command)
+            res.push_back(alias.first);
+    }
+
+    return res;
+}
+
+}

src/alias_registry.hh

@@ -0,0 +1,37 @@
+#ifndef alias_registry_hh_INCLUDED
+#define alias_registry_hh_INCLUDED
+
+#include "utils.hh"
+#include "safe_ptr.hh"
+#include "string.hh"
+
+#include <unordered_map>
+
+namespace Kakoune
+{
+
+class AliasRegistry : public SafeCountable
+{
+public:
+    AliasRegistry(AliasRegistry& parent) : m_parent(&parent) {}
+    void add_alias(String alias, String command);
+    void remove_alias(const String& alias);
+    StringView operator[](const String& name) const;
+
+    std::vector<StringView> aliases_for(StringView command) const;
+
+private:
+    friend class GlobalAliases;
+    AliasRegistry() {}
+
+    safe_ptr<AliasRegistry> m_parent;
+    std::unordered_map<String, String> m_aliases;
+};
+
+class GlobalAliases : public AliasRegistry, public Singleton<GlobalAliases>
+{};
+
+}
+
+#endif // alias_registry_hh_INCLUDED
+

src/buffer.cc

@@ -23,7 +23,8 @@ Buffer::Buffer(String name, Flags flags, std::vector<String> lines,
       m_fs_timestamp(fs_timestamp),
       m_hooks(GlobalHooks::instance()),
       m_options(GlobalOptions::instance()),
-      m_keymaps(GlobalKeymaps::instance())
+      m_keymaps(GlobalKeymaps::instance()),
+      m_aliases(GlobalAliases::instance())
 {
     BufferManager::instance().register_buffer(*this);
     m_options.register_watcher(*this);

src/buffer.hh

@@ -1,6 +1,7 @@
 #ifndef buffer_hh_INCLUDED
 #define buffer_hh_INCLUDED
 
+#include "alias_registry.hh"
 #include "coord.hh"
 #include "flags.hh"
 #include "hook_manager.hh"
@@ -155,6 +156,8 @@ public:
     const HookManager&   hooks()   const { return m_hooks; }
     KeymapManager&       keymaps()       { return m_keymaps; }
     const KeymapManager& keymaps() const { return m_keymaps; }
+    AliasRegistry&       aliases()       { return m_aliases; }
+    const AliasRegistry& aliases() const { return m_aliases; }
 
     ValueMap& values() const { return m_values; }
 
@@ -217,6 +220,7 @@ private:
     OptionManager m_options;
     HookManager   m_hooks;
     KeymapManager m_keymaps;
+    AliasRegistry m_aliases;
 
     // Values are just data holding by the buffer, so it is part of its
     // observable state

src/command_manager.cc

@@ -1,5 +1,6 @@
 #include "command_manager.hh"
 
+#include "alias_registry.hh"
 #include "assert.hh"
 #include "context.hh"
 #include "register_manager.hh"
@@ -13,7 +14,7 @@ namespace Kakoune
 
 bool CommandManager::command_defined(const String& command_name) const
 {
-    return find_command(command_name) != m_commands.end();
+    return m_commands.find(command_name) != m_commands.end();
 }
 
 void CommandManager::register_command(String command_name,
@@ -30,13 +31,6 @@ void CommandManager::register_command(String command_name,
                                  std::move(completer) };
 }
 
-void CommandManager::register_alias(String alias, String command)
-{
-    kak_assert(not alias.empty());
-    kak_assert(command_defined(command));
-    m_aliases[alias] = std::move(command);
-}
-
 struct parse_error : runtime_error
 {
     parse_error(const String& error)
@@ -347,10 +341,10 @@ struct command_not_found : runtime_error
 };
 
 CommandManager::CommandMap::const_iterator
-CommandManager::find_command(const String& name) const
+CommandManager::find_command(const Context& context, const String& name) const
 {
-    auto it = m_aliases.find(name);
+    auto alias = context.aliases()[name];
-    const String& cmd_name = it == m_aliases.end() ? name : it->second;
+    const String& cmd_name = alias.empty() ? name : alias.str();
 
     return m_commands.find(cmd_name);
 }
@@ -363,7 +357,7 @@ void CommandManager::execute_single_command(CommandParameters params,
         return;
 
     memoryview<String> param_view(params.begin()+1, params.end());
-    auto command_it = find_command(params[0]);
+    auto command_it = find_command(context, params[0]);
     if (command_it == m_commands.end())
         throw command_not_found(params[0]);
 
@@ -443,7 +437,7 @@ void CommandManager::execute(StringView command_line,
     execute_single_command(params, context, command_coord);
 }
 
-CommandInfo CommandManager::command_info(StringView command_line) const
+CommandInfo CommandManager::command_info(const Context& context, StringView command_line) const
 {
     TokenList tokens = parse<false>(command_line);
     size_t cmd_idx = 0;
@@ -458,7 +452,7 @@ CommandInfo CommandManager::command_info(StringView command_line) const
         tokens[cmd_idx].type() != Token::Type::Raw)
         return res;
 
-    auto cmd = find_command(tokens[cmd_idx].content());
+    auto cmd = find_command(context, tokens[cmd_idx].content());
     if (cmd == m_commands.end())
         return res;
 
@@ -467,11 +461,8 @@ CommandInfo CommandManager::command_info(StringView command_line) const
         res.second += cmd->second.docstring + "\n";
 
     String aliases;
-    for (auto& alias : m_aliases)
+    for (auto& alias : context.aliases().aliases_for(cmd->first))
-    {
+        aliases += " " + alias;
-        if (alias.second == cmd->first)
-            aliases += " " + alias.first;
-    }
     if (not aliases.empty())
         res.second += "Aliases:" + aliases + "\n";
 
@@ -562,7 +553,7 @@ Completions CommandManager::complete(const Context& context,
 
         const String& command_name = tokens[cmd_idx].content();
 
-        auto command_it = find_command(command_name);
+        auto command_it = find_command(context, command_name);
         if (command_it == m_commands.end() or
             not command_it->second.completer)
             return Completions();

src/command_manager.hh

@@ -65,7 +65,8 @@ public:
     Completions complete(const Context& context, CompletionFlags flags,
                          StringView command_line, ByteCount cursor_pos);
 
-    CommandInfo command_info(StringView command_line) const;
+    CommandInfo command_info(const Context& context,
+                             StringView command_line) const;
 
     bool command_defined(const String& command_name) const;
 
@@ -74,7 +75,6 @@ public:
                           ParameterDesc param_desc,
                           CommandFlags flags = CommandFlags::None,
                           CommandCompleter completer = CommandCompleter());
-   void register_alias(String alias, String command);
 
 private:
     void execute_single_command(CommandParameters params,
@@ -90,9 +90,9 @@ private:
     };
     using CommandMap = std::unordered_map<String, CommandDescriptor>;
     CommandMap m_commands;
-    std::unordered_map<String, String> m_aliases;
 
-    CommandMap::const_iterator find_command(const String& name) const;
+    CommandMap::const_iterator find_command(const Context& context,
+                                            const String& name) const;
 };
 
 }

src/commands.cc

@@ -82,6 +82,8 @@ const ParameterDesc single_optional_name_param{
     SwitchMap{}, ParameterDesc::Flags::None, 0, 1
 };
 
+static constexpr auto scopes = { "global", "buffer", "window" };
+
 struct CommandDesc
 {
     const char* name;
@@ -511,8 +513,6 @@ HookManager& get_hook_manager(const String& scope, const Context& context)
     throw runtime_error("error: no such hook container " + scope);
 }
 
-static constexpr auto scopes = { "global", "buffer", "window" };
-
 const CommandDesc add_hook_cmd = {
     "hook",
     nullptr,
@@ -613,14 +613,6 @@ void define_command(const ParametersParser& parser, Context& context)
     if (parser.has_option("docstring"))
         docstring = parser.option_value("docstring");
 
-    String alias;
-    if (parser.has_option("alias"))
-    {
-        alias = parser.option_value("alias");
-        if (alias.empty())
-            throw runtime_error("alias should not be an empty string");
-    }
-
     String commands = parser[1];
     Command cmd;
     ParameterDesc desc;
@@ -697,8 +689,6 @@ void define_command(const ParametersParser& parser, Context& context)
 
     auto& cm = CommandManager::instance();
     cm.register_command(cmd_name, cmd, std::move(docstring), desc, flags, completer);
-    if (not alias.empty())
-        cm.register_alias(std::move(alias), cmd_name);
 }
 
 const CommandDesc define_command_cmd = {
@@ -709,7 +699,6 @@ const CommandDesc define_command_cmd = {
         SwitchMap{ { "shell-params", { false, "pass parameters to each shell escape as $0..$N" } },
                    { "allow-override", { false, "allow overriding an existing command" } },
                    { "hidden", { false, "do not display the command in completion candidates" } },
-                   { "alias", { true, "define an alias for this command" } },
                    { "docstring", { true, "define the documentation string for command" } },
                    { "file-completion", { false, "complete parameters using filename completion" } },
                    { "client-completion", { false, "complete parameters using client name completion" } },
@@ -723,6 +712,49 @@ const CommandDesc define_command_cmd = {
     define_command
 };
 
+AliasRegistry& get_aliases(const String& scope, const Context& context)
+{
+    if (prefix_match("global", scope))
+        return GlobalAliases::instance();
+    else if (prefix_match("buffer", scope))
+        return context.buffer().aliases();
+    else if (prefix_match("window", scope))
+        return context.window().aliases();
+    throw runtime_error("error: no such scope " + scope);
+}
+
+const CommandDesc alias_cmd = {
+    "alias",
+    nullptr,
+    "alias <scope> <alias> <command>: define a command alias in given scope",
+    ParameterDesc{SwitchMap{}, ParameterDesc::Flags::None, 3, 3},
+    CommandFlags::None,
+    CommandCompleter{},
+    [](const ParametersParser& parser, Context& context)
+    {
+        AliasRegistry& aliases = get_aliases(parser[0], context);
+        aliases.add_alias(parser[1], parser[2]);
+    }
+};
+
+const CommandDesc unalias_cmd = {
+    "unalias",
+    nullptr,
+    "unalias <scope> <alias> [<expected>]: remove a command alias in given scope\n"
+    "if <expected> is specified, the alias is removed only if its value is <expected>",
+    ParameterDesc{SwitchMap{}, ParameterDesc::Flags::None, 2, 3},
+    CommandFlags::None,
+    CommandCompleter{},
+    [](const ParametersParser& parser, Context& context)
+    {
+        AliasRegistry& aliases = get_aliases(parser[0], context);
+        if (parser.positional_count() == 3 and
+            aliases[parser[1]] != parser[2])
+            return;
+        aliases.remove_alias(parser[1]);
+    }
+};
+
 const CommandDesc echo_cmd = {
     "echo",
     nullptr,
@@ -1387,7 +1419,7 @@ static void register_command(CommandManager& cm, const CommandDesc& c)
 {
     cm.register_command(c.name, c.func, c.docstring, c.params, c.flags, c.completer);
     if (c.alias)
-        cm.register_alias(c.alias, c.name);
+        GlobalAliases::instance().add_alias(c.alias, c.name);
 }
 
 void register_commands()
@@ -1414,6 +1446,8 @@ void register_commands()
     register_command(cm, add_hook_cmd);
     register_command(cm, rm_hook_cmd);
     register_command(cm, define_command_cmd);
+    register_command(cm, alias_cmd);
+    register_command(cm, unalias_cmd);
     register_command(cm, echo_cmd);
     register_command(cm, debug_cmd);
     register_command(cm, source_cmd);

src/context.cc

@@ -1,5 +1,6 @@
 #include "context.hh"
 
+#include "alias_registry.hh"
 #include "client.hh"
 #include "user_interface.hh"
 #include "register_manager.hh"
@@ -80,6 +81,15 @@ KeymapManager& Context::keymaps() const
     return GlobalKeymaps::instance();
 }
 
+AliasRegistry& Context::aliases() const
+{
+    if (has_window())
+        return window().aliases();
+    if (has_buffer())
+        return buffer().aliases();
+    return GlobalAliases::instance();
+}
+
 void Context::set_client(Client& client)
 {
     kak_assert(not has_client());

src/context.hh

@@ -14,6 +14,7 @@ class InputHandler;
 class UserInterface;
 class DisplayLine;
 class KeymapManager;
+class AliasRegistry;
 
 // A Context is used to access non singleton objects for various services
 // in commands.
@@ -60,6 +61,7 @@ public:
     OptionManager& options() const;
     HookManager& hooks() const;
     KeymapManager& keymaps() const;
+    AliasRegistry& aliases() const;
 
     void print_status(DisplayLine status) const;
 

src/main.cc

@@ -1,4 +1,5 @@
 #include "assert.hh"
+#include "alias_registry.hh"
 #include "buffer.hh"
 #include "buffer_manager.hh"
 #include "buffer_utils.hh"
@@ -317,6 +318,7 @@ int run_server(StringView session, StringView init_command,
     GlobalOptions       global_options;
     GlobalHooks         global_hooks;
     GlobalKeymaps       global_keymaps;
+    GlobalAliases       global_aliases;
     ShellManager        shell_manager;
     CommandManager      command_manager;
     BufferManager       buffer_manager;
@@ -399,6 +401,7 @@ int run_filter(StringView keystr, memoryview<StringView> files)
     GlobalOptions   global_options;
     GlobalHooks     global_hooks;
     GlobalKeymaps   global_keymaps;
+    GlobalAliases   global_aliases;
     ShellManager    shell_manager;
     BufferManager   buffer_manager;
     RegisterManager register_manager;

src/normal.cc

@@ -361,7 +361,7 @@ void command(Context& context, int)
                 context.ui().info_hide();
                 if (event == PromptEvent::Change and context.options()["autoinfo"].get<int>() > 0)
                 {
-                    auto info = CommandManager::instance().command_info(cmdline);
+                    auto info = CommandManager::instance().command_info(context, cmdline);
                     Face col = get_face("Information");
                     CharCoord pos = context.window().dimensions();
                     pos.column -= 1;

src/window.cc

@@ -21,7 +21,8 @@ Window::Window(Buffer& buffer)
     : m_buffer(&buffer),
       m_hooks(buffer.hooks()),
       m_options(buffer.options()),
-      m_keymaps(buffer.keymaps())
+      m_keymaps(buffer.keymaps()),
+      m_aliases(buffer.aliases())
 {
     InputHandler hook_handler{{ *m_buffer, Selection{} }};
     hook_handler.context().set_window(*this);

src/window.hh

@@ -1,6 +1,7 @@
 #ifndef window_hh_INCLUDED
 #define window_hh_INCLUDED
 
+#include "alias_registry.hh"
 #include "completion.hh"
 #include "display_buffer.hh"
 #include "highlighter_group.hh"
@@ -44,6 +45,8 @@ public:
     const HookManager&   hooks()   const { return m_hooks; }
     KeymapManager&       keymaps()       { return m_keymaps; }
     const KeymapManager& keymaps() const { return m_keymaps; }
+    AliasRegistry&       aliases()       { return m_aliases; }
+    const AliasRegistry& aliases() const { return m_aliases; }
 
     Buffer& buffer() const { return *m_buffer; }
 
@@ -67,6 +70,7 @@ private:
     HookManager      m_hooks;
     OptionManager    m_options;
     KeymapManager    m_keymaps;
+    AliasRegistry    m_aliases;
 
     HighlighterGroup m_highlighters;
     HighlighterGroup m_builtin_highlighters;