implement ordering by specific values

src/OrderBy/OrderBy.php

@@ -5,31 +5,11 @@ declare(strict_types=1);
 namespace Grifart\Tables\OrderBy;
 
 use Dibi\Expression as DibiExpression;
-use Grifart\Tables\Expression;
 
-final class OrderBy
+interface OrderBy
 {
-	private readonly Nulls $nulls;
-
 	/**
-	 * @param Expression<mixed> $expression
+	 * @return DibiExpression the ORDER BY part of a Dibi query
 	 */
-	public function __construct(
-		private readonly Expression $expression,
-		private readonly Direction $direction = Direction::Ascending,
-		Nulls|null $nulls = null,
-	)
-	{
-		$this->nulls = $nulls ?? Nulls::default($this->direction);
-	}
-
-	public function toSql(): DibiExpression
-	{
-		return new DibiExpression(
-			'? %ex %ex',
-			$this->expression->toSql(),
-			$this->direction->toSql(),
-			$this->nulls->toSql(),
-		);
-	}
+	public function toSql(): DibiExpression;
 }