add Span class and use it from TextLoader

src/core/TextLoader.h

@@ -4,6 +4,7 @@
 #include <stdint.h>
 #include <list>
 #include <memory>
+#include "Span.h"
 
 class TextLoader
 {
@@ -34,14 +35,10 @@ public:
     auto end() { return m_lines->end(); }
     bool get_eol_at_eof() { return m_eol_at_eof; }
 
-    typedef std::pair<uint8_t *, uint32_t> LineIndexPair;
-    typedef std::list<LineIndexPair> LineIndexPairList;
-    typedef std::shared_ptr<LineIndexPairList> LineIndexPairListRef;
-
 protected:
     int m_line_endings;
     bool m_eol_at_eof;
-    LineIndexPairListRef m_lines;
+    std::shared_ptr<std::list<Span>> m_lines;
 };
 
 #endif