add Buffer::insert_code_point()

src/core/Buffer.cc

@@ -161,3 +161,14 @@ void Buffer::exit_insert_mode()
 {
     m_insert_mode = false;
 }
+
+void Buffer::insert_code_point(uint32_t code_point)
+{
+    if (m_insert_mode)
+    {
+        uint8_t encoded[Encoding::MAX_CODE_POINT_SIZE];
+        uint8_t bytes = Encoding::encode(code_point, m_encoding, encoded);
+        m_gap_buffer->insert(m_insert_position, encoded, bytes);
+        m_insert_position += bytes;
+    }
+}

src/core/Buffer.h

@@ -103,6 +103,7 @@ public:
     void enter_insert_mode(const Buffer::Iterator & position);
     void exit_insert_mode();
     bool insert_mode() const { return m_insert_mode; }
+    void insert_code_point(uint32_t code_point);
 
 protected:
     bool m_eol_at_eof;

src/core/Encoding.h

@@ -13,9 +13,9 @@ public:
         CP_1252,
     };
 
-    enum
+    enum : uint32_t
     {
-        MAX_CODE_POINT_SIZE = 8,
+        MAX_CODE_POINT_SIZE = 8u,
     };
 
     static Type detect_encoding(const uint8_t * buffer, size_t length);