adjust cursor movement to optionally allow moving to EOL

src/core/PieceTable.cc

@@ -138,7 +138,7 @@ bool PieceTable::Cursor::go_start_of_line()
     return rv;
 }
 
-bool PieceTable::Cursor::go_end_of_line()
+bool PieceTable::Cursor::go_end_of_line(bool allow_on_eol)
 {
     if (!iterator.valid())
         return false;
@@ -148,11 +148,14 @@ bool PieceTable::Cursor::go_end_of_line()
             (iterator.piece->next != iterator.piece_table->end_piece))
     {
         iterator.go_next_piece();
-        rv = true;
     }
     uint32_t current_column = column;
     iterator.go_end_of_piece();
     calculate_column();
+    if (!allow_on_eol)
+    {
+        go_left(1);
+    }
     if (column != current_column)
         rv = true;
     return rv;
@@ -214,7 +217,7 @@ bool PieceTable::Cursor::go_left(int n)
     return true;
 }
 
-bool PieceTable::Cursor::go_right(int n)
+bool PieceTable::Cursor::go_right(int n, bool allow_on_eol)
 {
     if (!iterator.valid())
         return false;
@@ -222,7 +225,13 @@ bool PieceTable::Cursor::go_right(int n)
     {
         return false;
     }
+    Iterator iterator_2 = iterator;
     iterator.go_next_position();
+    if ((!allow_on_eol) && is_end_of_line())
+    {
+        iterator = iterator_2;
+        return false;
+    }
     uint32_t chr = *iterator;
     if (chr == '\t')
     {
@@ -307,7 +316,7 @@ void PieceTable::Cursor::calculate_column()
     while ((tmp_cursor.iterator.piece != iterator.piece) ||
             (tmp_cursor.iterator.offset < iterator.offset))
     {
-        tmp_cursor.go_right(1);
+        tmp_cursor.go_right(1, true);
     }
     column = tmp_cursor.column;
 }
@@ -317,7 +326,7 @@ void PieceTable::Cursor::forward_to_column(uint32_t c)
     int32_t diff = abs((int32_t)(c - column));
     if (diff == 0)
         return;
-    while (go_right(1))
+    while (go_right(1, false))
     {
         int32_t new_diff = abs((int32_t)(c - column));
         if (new_diff > diff)

src/core/PieceTable.h

@@ -102,11 +102,11 @@ public:
         Cursor(PieceTable * pt);
 
         bool go_start_of_line();
-        bool go_end_of_line();
+        bool go_end_of_line(bool allow_on_eol);
         bool go_up(int n, uint32_t desired_column);
         bool go_down(int n, uint32_t desired_column);
         bool go_left(int n);
-        bool go_right(int n);
+        bool go_right(int n, bool allow_on_eol);
         bool operator==(const Cursor & c)
         {
             return (c.line == line) && (c.column == column);