1 files changed, 84 insertions, 0 deletions
diff --git a/src/register_manager.cc b/src/register_manager.cc
new file mode 100644
index 00000000..857f7324
--- /dev/null
+++ b/src/register_manager.cc
@@ -0,0 +1,84 @@
+#include "register_manager.hh"
+
+#include "utils.hh"
+#include "assert.hh"
+
+namespace Kakoune
+{
+
+// static value register, which can be modified
+// using operator=, so should be user modifiable
+class StaticRegister : public Register
+{
+public:
+    Register& operator=(const memoryview<String>& values)
+    {
+        m_content = std::vector<String>(values.begin(), values.end());
+        return *this;
+    }
+
+    const String& operator[](size_t index)
+    {
+        if (m_content.size() > index)
+            return m_content[index];
+        else
+            return ms_empty;
+    }
+
+    operator memoryview<String>()
+    {
+        return memoryview<String>(m_content);
+    }
+protected:
+    std::vector<String> m_content;
+
+    static const String ms_empty;
+};
+
+const String StaticRegister::ms_empty;
+
+// Dynamic value register, use it's RegisterRetriever
+// to get it's value when needed.
+class DynamicRegister : public StaticRegister
+{
+public:
+    DynamicRegister(RegisterRetriever function)
+        : m_function(std::move(function)) {}
+
+    Register& operator=(const memoryview<String>& values)
+    {
+        throw runtime_error("this register is not assignable");
+    }
+
+    const String& operator[](size_t index)
+    {
+        m_content = m_function();
+        return StaticRegister::operator[](index);
+    }
+
+    operator memoryview<String>()
+    {
+        m_content = m_function();
+        return StaticRegister::operator memoryview<String>();
+    }
+
+private:
+    RegisterRetriever   m_function;
+};
+
+Register& RegisterManager::operator[](char reg)
+{
+    auto& reg_ptr = m_registers[reg];
+    if (not reg_ptr)
+        reg_ptr.reset(new StaticRegister());
+    return *reg_ptr;
+}
+
+void RegisterManager::register_dynamic_register(char reg, RegisterRetriever function)
+{
+    auto& reg_ptr = m_registers[reg];
+    assert(not reg_ptr);
+    reg_ptr.reset(new DynamicRegister(std::move(function)));
+}
+
+}