Use a IdMap for storing hooks

The number of hook names is small (<20), using an UnorderedMap
is overkill, and prevents using StringView for key searching.

src/buffer.cc

@@ -516,7 +516,7 @@ void Buffer::on_option_changed(const Option& option)
                             option.name() + "=" + option.get_as_string());
 }
 
-void Buffer::run_hook_in_own_context(const String& hook_name, StringView param)
+void Buffer::run_hook_in_own_context(StringView hook_name, StringView param)
 {
     InputHandler hook_handler({ *this, Selection{} }, Context::Flags::Transient);
     hooks().run_hook(hook_name, param, hook_handler.context());

src/buffer.hh

@@ -150,7 +150,7 @@ public:
 
     ValueMap& values() const { return m_values; }
 
-    void run_hook_in_own_context(const String& hook_name, StringView param);
+    void run_hook_in_own_context(StringView hook_name, StringView param);
 
     void reload(BufferLines lines, time_t fs_timestamp = InvalidTime);
 

src/hook_manager.cc

@@ -8,7 +8,7 @@
 namespace Kakoune
 {
 
-void HookManager::add_hook(const String& hook_name, String group, HookFunc hook)
+void HookManager::add_hook(StringView hook_name, String group, HookFunc hook)
 {
     auto& hooks = m_hook[hook_name];
     hooks.append({std::move(group), std::move(hook)});
@@ -37,7 +37,7 @@ CandidateList HookManager::complete_hook_group(StringView prefix, ByteCount pos_
     return res;
 }
 
-void HookManager::run_hook(const String& hook_name,
+void HookManager::run_hook(StringView hook_name,
                            StringView param, Context& context) const
 {
     if (m_parent)

src/hook_manager.hh

@@ -16,10 +16,10 @@ class HookManager
 public:
     HookManager(HookManager& parent) : m_parent(&parent) {}
 
-    void add_hook(const String& hook_name, String group, HookFunc hook);
+    void add_hook(StringView hook_name, String group, HookFunc hook);
     void remove_hooks(StringView group);
     CandidateList complete_hook_group(StringView prefix, ByteCount pos_in_token);
-    void run_hook(const String& hook_name, StringView param,
+    void run_hook(StringView hook_name, StringView param,
                   Context& context) const;
 
 private:
@@ -29,7 +29,7 @@ private:
     friend class Scope;
 
     HookManager* m_parent;
-    UnorderedMap<String, IdMap<HookFunc, MemoryDomain::Hooks>, MemoryDomain::Hooks> m_hook;
+    IdMap<IdMap<HookFunc, MemoryDomain::Hooks>, MemoryDomain::Hooks> m_hook;
 };
 
 }

src/id_map.hh

@@ -59,6 +59,21 @@ public:
         m_content.erase(it, end());
     }
 
+    Value& operator[](StringView id)
+    {
+        auto it = find(id);
+        if (it != m_content.end())
+            return it->second;
+
+        append({ id, Value{} });
+        return (m_content.end()-1)->second;
+    }
+
+    const Value& operator[](StringView id) const
+    {
+        return (*const_cast<IdMap*>(this))[id];
+    }
+
     static const String& get_id(const value_type& v) { return v.first; }
 
     bool empty() const { return m_content.empty(); }

src/window.cc

@@ -282,7 +282,7 @@ void Window::on_option_changed(const Option& option)
 }
 
 
-void Window::run_hook_in_own_context(const String& hook_name, StringView param)
+void Window::run_hook_in_own_context(StringView hook_name, StringView param)
 {
     InputHandler hook_handler({ *m_buffer, Selection{} }, Context::Flags::Transient);
     hook_handler.context().set_window(*this);

src/window.hh

@@ -50,7 +50,7 @@ private:
     void on_option_changed(const Option& option) override;
     void scroll_to_keep_selection_visible_ifn(const Context& context);
 
-    void run_hook_in_own_context(const String& hook_name, StringView param);
+    void run_hook_in_own_context(StringView hook_name, StringView param);
 
     SafePtr<Buffer> m_buffer;