first successful run to solve a simple puzzle

board/field.go

@@ -82,10 +82,28 @@ func (f *Field) GetBlock(r, c int) (*Block, error) {
 			block.cells[row][column] = &f.cells[startRow+row][startCol+column]
 		}
 	}
-
 	return block, nil
 }
 
+func (f *Field) GetEachPartAtPos(pos *Position) []Part {
+	row, err := f.GetRow(pos.row)
+	if err != nil {
+		return nil
+	}
+
+	column, err := f.GetColumn(pos.column)
+	if err != nil {
+		return nil
+	}
+
+	block, err := f.GetBlock(pos.blockRow, pos.blockColumn)
+	if err != nil {
+		return nil
+	}
+
+	return append([]Part{}, row, column, block)
+}
+
 func (f *Field) GetCell(r, c int) (*Cell, error) {
 	if r > f.rows || c > f.columns {
 		return nil, outOfBound
@@ -111,6 +129,13 @@ func (f *Field) ForEachPart(fn func(part Part)) {
 	})
 }
 
+func (f *Field) ForEachPartAtPos(pos *Position, fn func(part Part)) {
+	parts := f.GetEachPartAtPos(pos)
+	for _, part := range parts {
+		fn(part)
+	}
+}
+
 func (f *Field) ForEachRow(fn func(row *Row)) {
 	for i := range f.rows {
 		row, err := f.GetRow(i)