Implement Cursor go_start_of_line()/go_end_of_line()

src/core/GapBuffer.cc

@@ -103,12 +103,40 @@ bool GapBuffer::Cursor::is_start_of_line()
 
 bool GapBuffer::Cursor::go_start_of_line()
 {
-    /* TODO */
+    bool moved = false;
+    Iterator i2 = m_iterator;
+    for (;;)
+    {
+        i2.back();
+        if (i2.valid() && (*i2 != '\n'))
+        {
+            moved = true;
+            m_iterator = i2;
+        }
+        else
+        {
+            break;
+        }
+    }
+    if (moved)
+    {
+        init_column();
+    }
+    return moved;
 }
 
 bool GapBuffer::Cursor::go_end_of_line()
 {
-    /* TODO */
+    bool moved = false;
+    if (go_right())
+    {
+        moved = true;
+    }
+    while (go_right())
+    {
+        ;
+    }
+    return moved;
 }
 
 bool GapBuffer::Cursor::go_left()
@@ -156,6 +184,18 @@ bool GapBuffer::Cursor::go_right()
     return false;
 }
 
+void GapBuffer::Cursor::init_column()
+{
+    if (*m_iterator == '\t')
+    {
+        m_column = m_iterator.gap_buffer()->tabstop - 1u;
+    }
+    else
+    {
+        m_column = 0u;
+    }
+}
+
 void GapBuffer::Cursor::calculate_column()
 {
     Cursor tmp_cursor = *this;

src/core/GapBuffer.h

@@ -59,7 +59,7 @@ public:
             : m_iterator(gap_buffer)
         {
             m_line = 0u;
-            m_column = 0u;
+            init_column();
         }
         bool is_start_of_line();
         bool is_end_of_line()
@@ -80,6 +80,7 @@ public:
         size_t m_line;
         size_t m_column;
 
+        void init_column();
         void calculate_column();
     };