remove the expr::group feature, which caused a 20x slowdown in benchm…

…ark - this change restores performance. the implications in terms of how many extra parens get added are actually quite reasonable - the conditional grouping feature seems to make very little difference on complex queries in practice. win/win :-)

src/model/expr.php

@@ -21,7 +21,7 @@ public static function any(array $exprs): string
         }
 
         return count($exprs) > 1
-            ? implode(" OR ", array_map(self::group(...), $exprs))
+            ? "(" . implode(") OR (", $exprs) . ")"
             : $exprs[0];
     }
 
@@ -37,19 +37,7 @@ public static function all(array $exprs): string
         }
 
         return count($exprs) > 1
-            ? implode(" AND ", array_map(self::group(...), $exprs))
+            ? "(" . implode(") AND (", $exprs) . ")"
             : $exprs[0];
     }
-
-    private const FULLY_GROUPED = '/^\((?:[^()]*|\((?:[^()]*|\([^()]*\))*\))*\)$/';
-
-    /**
-     * Group an expression in parentheses, if not already fully grouped
-     */
-    public static function group(string $expr): string
-    {
-        return preg_match(self::FULLY_GROUPED, $expr) === 1
-            ? $expr
-            : "($expr)";
-    }
 }

test/test-unit.php

@@ -888,19 +888,6 @@ function () {
     }
 );
 
-test(
-    'can conditionally group SQL expressions',
-    function () {
-        eq(expr::group('a OR b'), '(a OR b)', 'should group');
-        eq(expr::group('(a) OR b'), '((a) OR b)', 'should group');
-        eq(expr::group('(a) OR (b)'), '((a) OR (b))', 'should group');
-
-        eq(expr::group('(a OR b)'), '(a OR b)', 'should not regroup');
-        eq(expr::group('((a) OR b)'), '((a) OR b)', 'should not regroup');
-        eq(expr::group('((a) OR (b))'), '((a) OR (b))', 'should not regroup');
-    }
-);
-
 test(
     'can build and/or expressions',
     function () {
@@ -930,8 +917,8 @@ function () {
                 '(a OR b)',
                 '(c OR d)'
             ]),
-            '(a OR b) AND (c OR d)',
-            'should not regroup nested expressions'
+            '((a OR b)) AND ((c OR d))',
+            'grouped expressions will be regrouped'
         );
 
         eq(