Change Buffer::erase_range() to take a Range argument

src/core/Buffer.cc

@@ -212,15 +212,12 @@ void Buffer::erase_code_point(const Buffer::Iterator & position)
     }
 }
 
-void Buffer::erase_range(const Buffer::Iterator & start,
-        const Buffer::Iterator & end)
+void Buffer::erase_range(const Buffer::Range & range)
 {
-    if (start.valid() && (start < end))
+    if (range.valid() && (range.size() > 0u))
     {
         push_operation();
-        size_t start_offset = start.offset();
-        size_t end_offset = end.valid() ? end.offset() : m_gap_buffer->size();
-        erase_data(start_offset, end_offset - start_offset, true);
+        erase_data(range.start_offset(), range.size(), true);
         pop_operation();
     }
 }

src/core/Buffer.h

@@ -173,8 +173,7 @@ public:
     bool insert_mode() const { return m_insert_mode; }
     void insert_code_point(const Buffer::Iterator & position, uint32_t code_point);
     void erase_code_point(const Buffer::Iterator & position);
-    void erase_range(const Buffer::Iterator & start,
-            const Buffer::Iterator & end);
+    void erase_range(const Buffer::Range & range);
     std::shared_ptr<std::string> filename() const { return m_filename; }
     Iterator begin() const { return Iterator(this); }
     std::shared_ptr<Iterator> beginp() const { return std::make_shared<Iterator>(this); }