Separate PieceTable::Cursor::go_*() into go_*() and check_go_*()

src/core/PieceTable.cc

@@ -148,89 +148,109 @@ PieceTable::Cursor::Cursor(PieceTable * pt) : iterator(pt)
     init_column();
 }
 
-bool PieceTable::Cursor::go_start_of_line()
+void PieceTable::Cursor::go_start_of_line()
 {
     if (!iterator.valid())
-        return false;
-    bool rv = false;
+        return;
     while (iterator.valid() &&
             (!iterator.piece->prev->eol()) &&
             (iterator.piece->prev != iterator.piece_table->start_piece))
     {
         iterator.go_prev_piece();
-        rv = true;
     }
-    if (iterator.offset != 0u)
-        rv = true;
     iterator.offset = 0u;
     init_column();
-    return rv;
 }
 
-bool PieceTable::Cursor::go_end_of_line(bool allow_on_eol)
+bool PieceTable::Cursor::check_go_start_of_line()
+{
+    uint32_t current_line = line;
+    uint32_t current_column = column;
+    go_start_of_line();
+    return (current_line != line) || (current_column != column);
+}
+
+void PieceTable::Cursor::go_end_of_line(bool allow_on_eol)
 {
     if (!iterator.valid())
-        return false;
-    bool rv = false;
+        return;
     while (iterator.valid() &&
             (!iterator.piece->eol()) &&
             (iterator.piece->next != iterator.piece_table->end_piece))
     {
         iterator.go_next_piece();
     }
-    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;
 }
 
-bool PieceTable::Cursor::go_up(int n, uint32_t desired_column)
+bool PieceTable::Cursor::check_go_end_of_line(bool allow_on_eol)
+{
+    uint32_t current_line = line;
+    uint32_t current_column = column;
+    go_end_of_line(allow_on_eol);
+    return (current_line != line) || (current_column != column);
+}
+
+void PieceTable::Cursor::go_up(int n, uint32_t desired_column)
 {
     if (!iterator.valid())
-        return false;
+        return;
     Piece * p = prev_line();
     if (p == nullptr)
     {
-        return false;
+        return;
     }
     iterator.piece = p;
     iterator.offset = 0u;
     line--;
     init_column();
     forward_to_column(desired_column);
-    return true;
 }
 
-bool PieceTable::Cursor::go_down(int n, uint32_t desired_column)
+bool PieceTable::Cursor::check_go_up(int n, uint32_t desired_column)
+{
+    uint32_t current_line = line;
+    uint32_t current_column = column;
+    go_up(n, desired_column);
+    return (current_line != line) || (current_column != column);
+}
+
+void PieceTable::Cursor::go_down(int n, uint32_t desired_column)
 {
     if (!iterator.valid())
-        return false;
+        return;
     Piece * p = next_line();
     if (p == nullptr)
     {
-        return false;
+        return;
     }
     iterator.piece = p;
     iterator.offset = 0u;
     line++;
     init_column();
     forward_to_column(desired_column);
-    return true;
 }
 
-bool PieceTable::Cursor::go_left(int n)
+bool PieceTable::Cursor::check_go_down(int n, uint32_t desired_column)
+{
+    uint32_t current_line = line;
+    uint32_t current_column = column;
+    go_down(n, desired_column);
+    return (current_line != line) || (current_column != column);
+}
+
+void PieceTable::Cursor::go_left(int n)
 {
     if (!iterator.valid())
-        return false;
+        return;
     if (is_start_of_line())
     {
-        return false;
+        return;
     }
     uint32_t chr = *iterator;
     iterator.go_prev_position();
@@ -243,23 +263,30 @@ bool PieceTable::Cursor::go_left(int n)
         /* TODO: handle multi-column characters */
         column--;
     }
-    return true;
 }
 
-bool PieceTable::Cursor::go_right(int n, bool allow_on_eol)
+bool PieceTable::Cursor::check_go_left(int n)
+{
+    uint32_t current_line = line;
+    uint32_t current_column = column;
+    go_left(n);
+    return (current_line != line) || (current_column != column);
+}
+
+void PieceTable::Cursor::go_right(int n, bool allow_on_eol)
 {
     if (!iterator.valid())
-        return false;
+        return;
     if (is_end_of_line())
     {
-        return false;
+        return;
     }
     Iterator iterator_2 = iterator;
     iterator.go_next_position();
     if ((!allow_on_eol) && is_end_of_line())
     {
         iterator = iterator_2;
-        return false;
+        return;
     }
     uint32_t chr = *iterator;
     if (chr == '\t')
@@ -272,7 +299,14 @@ bool PieceTable::Cursor::go_right(int n, bool allow_on_eol)
         /* TODO: handle multi-column characters */
         column++;
     }
-    return true;
+}
+
+bool PieceTable::Cursor::check_go_right(int n, bool allow_on_eol)
+{
+    uint32_t current_line = line;
+    uint32_t current_column = column;
+    go_right(n, allow_on_eol);
+    return (current_line != line) || (current_column != column);
 }
 
 void PieceTable::Cursor::warp_to_inserted_piece(Piece * piece)
@@ -355,7 +389,7 @@ 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, false))
+    while (check_go_right(1, false))
     {
         int32_t new_diff = abs((int32_t)(c - column));
         if (new_diff > diff)

src/core/PieceTable.h

@@ -96,12 +96,20 @@ public:
 
         Cursor(PieceTable * pt);
 
-        bool go_start_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 allow_on_eol);
+        void go_start_of_line();
+        void go_end_of_line(bool allow_on_eol);
+        void go_up(int n, uint32_t desired_column);
+        void go_down(int n, uint32_t desired_column);
+        void go_left(int n);
+        void go_right(int n, bool allow_on_eol);
+
+        bool check_go_start_of_line();
+        bool check_go_end_of_line(bool allow_on_eol);
+        bool check_go_up(int n, uint32_t desired_column);
+        bool check_go_down(int n, uint32_t desired_column);
+        bool check_go_left(int n);
+        bool check_go_right(int n, bool allow_on_eol);
+
         bool operator==(const Cursor & c)
         {
             return (c.line == line) && (c.column == column);