add GapBuffer::clear() and GapBuffer::set_string()

src/core/GapBuffer.cc

@@ -50,12 +50,24 @@ void GapBuffer::erase(size_t position, size_t length)
     }
 }
 
+void GapBuffer::clear()
+{
+    m_size = 0u;
+    m_gap_position = 0u;
+}
+
 std::string GapBuffer::get_string()
 {
     compact();
     return std::string((char *)m_buffer, m_size);
 }
 
+void GapBuffer::set_string(std::string s)
+{
+    clear();
+    insert(0u, (const uint8_t *)s.c_str(), s.size());
+}
+
 void GapBuffer::ensure_free(size_t length)
 {
     if (gap_size() < length)

src/core/GapBuffer.h

@@ -56,6 +56,11 @@ public:
      */
     void erase(size_t position, size_t length);
 
+    /**
+     * Erase all data from the gap buffer.
+     */
+    void clear();
+
     /**
      * Get the contents of the gap buffer as a string.
      *
@@ -64,6 +69,11 @@ public:
      */
     std::string get_string();
 
+    /**
+     * Replace the buffer contents with a string.
+     */
+    void set_string(std::string s);
+
     /**
      * Get the size of the data stored within the buffer.
      */