Add support for long names for registers

We can now access register / with the name slash, * with star,
and | with pipe

Fixes #23

src/command_manager.cc

@@ -313,9 +313,7 @@ String eval_token(const Token& token, Context& context,
         return ShellManager::instance().eval(content, context, shell_params,
                                              env_vars);
     case Token::Type::RegisterExpand:
-        if (content.length() != 1)
-            throw runtime_error("wrong register name: " + content);
-        return RegisterManager::instance()[content[0]].values(context)[0];
+        return RegisterManager::instance()[content].values(context)[0];
     case Token::Type::OptionExpand:
         return context.options()[content].get_as_string();
     case Token::Type::RawEval:

src/commands.cc

@@ -1269,9 +1269,7 @@ const CommandDesc set_register_cmd = {
     CommandCompleter{},
     [](const ParametersParser& parser, Context& context)
     {
-        if (parser[0].length() != 1)
-            throw runtime_error("register names are single character");
-        RegisterManager::instance()[parser[0][0]] = memoryview<String>(parser[1]);
+        RegisterManager::instance()[parser[0]] = memoryview<String>(parser[1]);
     }
 };
 

src/main.cc

@@ -106,7 +106,7 @@ void register_env_vars()
         }, {
             "reg_.+",
             [](StringView name, const Context& context) -> String
-            { return RegisterManager::instance()[name[4]].values(context)[0]; }
+            { return RegisterManager::instance()[name.substr(4_byte)].values(context)[0]; }
         }, {
             "client_env_.+",
             [](StringView name, const Context& context) -> String

src/register_manager.cc

@@ -1,6 +1,7 @@
 #include "register_manager.hh"
 
 #include "assert.hh"
+#include "id_map.hh"
 #include "utils.hh"
 
 namespace Kakoune
@@ -55,9 +56,25 @@ private:
     RegisterRetriever   m_function;
 };
 
-Register& RegisterManager::operator[](char reg)
+Register& RegisterManager::operator[](StringView reg)
 {
-    auto& reg_ptr = m_registers[reg];
+    if (reg.length() == 1)
+        return (*this)[reg[0]];
+
+    static const id_map<Codepoint> reg_names = {
+        { "slash", '/' },
+        { "dquote", '"' },
+        { "pipe", '|' }
+    };
+    auto it = reg_names.find(reg);
+    if (it == reg_names.end())
+        throw runtime_error("no such register: " + reg);
+    return (*this)[it->second];
+}
+
+Register& RegisterManager::operator[](Codepoint c)
+{
+    auto& reg_ptr = m_registers[c];
     if (not reg_ptr)
         reg_ptr.reset(new StaticRegister());
     return *reg_ptr;

src/register_manager.hh

@@ -16,7 +16,8 @@ using RegisterRetriever = std::function<std::vector<String> (const Context&)>;
 class RegisterManager : public Singleton<RegisterManager>
 {
 public:
-    Register& operator[](char reg);
+    Register& operator[](StringView reg);
+    Register& operator[](Codepoint c);
     void register_dynamic_register(char reg, RegisterRetriever function);
 
 protected: