diff --git a/src/php/coll/Cursor.php b/src/php/coll/Cursor.php
index f1ec9d9..b10d011 100644
--- a/src/php/coll/Cursor.php
+++ b/src/php/coll/Cursor.php
@@ -2,6 +2,7 @@
 namespace nur\sery\wip\php\coll;
 
 use Iterator;
+use IteratorAggregate;
 use nulib\cl;
 use nulib\php\func;
 use nur\sery\wip\php\iter;
@@ -33,7 +34,7 @@ class Cursor implements Iterator {
    * alors retourner le tableau
    *   ["a" => $row["a"], "b" => $row["x"], "c" => "y", "d" => null]
    */
-  private static function map_row(array $row, ?array $map): array {
+  protected static function map_row(array $row, ?array $map): array {
     if ($map === null) return $row;
     $index = 0;
     $mapped = [];
@@ -48,7 +49,7 @@ class Cursor implements Iterator {
         $mapped[$key] = $func->invoke([$value, $key, $row]);
       } else {
         if ($value === null) $mapped[$key] = null;
-        else $mapped[$key] = cl::get($row, $key);
+        else $mapped[$key] = cl::get($row, $value);
       }
     }
     return $mapped;
@@ -67,7 +68,7 @@ class Cursor implements Iterator {
    * - une valeur associative $key => $value indique que la clé correspondante
    * doit exiter avec la valeur spécifiée
    */
-  private static function filter_row(array $row, $filter): bool {
+  protected static function filter_row(array $row, $filter): bool {
     if ($filter === null) return false;
     if (!is_array($filter)) $filter = [$filter];
     if (!$filter) return false;
@@ -79,12 +80,12 @@ class Cursor implements Iterator {
         if (!array_key_exists($value, $row)) return false;
       } elseif (is_bool($value)) {
         if ($value) {
-          if (!array_key_exists($value, $row)) return false;
+          if (!array_key_exists($key, $row)) return false;
         } else {
-          if (array_key_exists($value, $row)) return false;
+          if (array_key_exists($key, $row)) return false;
         }
       } else {
-        if (!array_key_exists($value, $row)) return false;
+        if (!array_key_exists($key, $row)) return false;
         if ($row[$key] !== $value) return false;
       }
     }
@@ -114,6 +115,11 @@ class Cursor implements Iterator {
     $this->rowsGenerator = $rowsGenerator;
     $this->rowsFunc = $rowsFunc;
 
+    $this->cols = $params["cols"] ?? null;
+    $colsFunc = $params["cols_func"] ?? null;
+    if ($colsFunc !== null) $colsFunc = func::with($colsFunc);
+    $this->colsFunc = $colsFunc;
+
     $map = $params["map"] ?? null;
     $mapFunc = $params["map_func"] ?? null;
     if ($mapFunc !== null) {
@@ -140,16 +146,16 @@ class Cursor implements Iterator {
   /** un générateur de lignes */
   private ?Traversable $rowsGenerator;
 
-  /** une fonction de signature <code>function(Cursor):?iterable</code> */
+  /** une fonction de signature <code>function(Cursor): ?iterable</code> */
   private ?func $rowsFunc;
 
-  /** une fonction de signature <code>function(Cursor):?array</code> */
+  /** une fonction de signature <code>function(Cursor): ?array</code> */
   private ?func $colsFunc;
 
-  /** une fonction de signature <code>function(Cursor):?array</code> */
+  /** une fonction de signature <code>function(Cursor): ?array</code> */
   private ?func $mapFunc;
 
-  /** une fonction de signature <code>function(Cursor):bool</code> */
+  /** une fonction de signature <code>function(Cursor): bool</code> */
   private ?func $filterFunc;
 
   protected ?iterable $rows;
@@ -173,6 +179,10 @@ class Cursor implements Iterator {
     return null;
   }
 
+  protected function cols(): ?array {
+    return $this->row !== null? array_keys($this->row): null;
+  }
+
   protected function filter(): bool {
     return false;
   }
@@ -185,20 +195,24 @@ class Cursor implements Iterator {
   # Iterator
 
   function rewind() {
+    $this->cols = null;
     $this->index = 0;
     $this->origIndex = 0;
     $this->key = null;
     $this->raw = null;
     $this->row = null;
     if ($this->rowsGenerator !== null) {
-      $this->rows = $this->rowsGenerator;
-      $this->rows->rewind();
+      $rows = $this->rowsGenerator;
+      if ($rows instanceof IteratorAggregate) $rows = $rows->getIterator();
+      $rows->rewind();
+      $this->rows = $rows;
     } else {
       $this->rows = $this->rowsFunc->invoke();
     }
   }
 
-  function valid() {
+  function valid(): bool {
+    $cols = $this->colsFunc;
     $filter = $this->filterFunc;
     $map = $this->mapFunc;
     while ($valid = iter::valid($this->rows)) {
@@ -210,6 +224,10 @@ class Cursor implements Iterator {
       if (!$filtered) {
         if ($map === null) $this->row = $this->map();
         else $this->row = $map->invoke([$this]);
+        if ($this->cols === null) {
+          if ($cols === null) $this->cols = $this->cols();
+          else $this->cols = $cols->invoke([$this]);
+        }
         break;
       } else {
         iter::next($this->rows);
@@ -219,6 +237,7 @@ class Cursor implements Iterator {
     if (!$valid) {
       iter::close($this->rows);
       $this->rows = null;
+      $this->cols = null;
       $this->index = -1;
       $this->origIndex = -1;
       $this->key = null;
@@ -228,7 +247,7 @@ class Cursor implements Iterator {
     return $valid;
   }
 
-  function current() {
+  function current(): ?array {
     return $this->row;
   }
 
diff --git a/tests/wip/php/coll/CursorTest.php b/tests/wip/php/coll/CursorTest.php
index ec820d8..f28bc95 100644
--- a/tests/wip/php/coll/CursorTest.php
+++ b/tests/wip/php/coll/CursorTest.php
@@ -13,6 +13,43 @@ class CursorTest extends TestCase {
     msg::set_messenger(new StdMessenger());
   }
 
+  function test_map_row() {
+    $cursor = new class extends Cursor {
+      function mapRow(array $row, ?array $map): array {
+        return self::map_row($row, $map);
+      }
+    };
+    $row = ["a" => 1, "b" => 2, "c" => 3, "x" => 99];
+    $map = ["a", "b" => "x", "c" => function() { return "y"; }, "d" => null];
+    self::assertSame([
+      "a" => $row["a"],
+      "b" => $row["x"],
+      "c" => "y",
+      "d" => null
+    ], $cursor->mapRow($row, $map));
+  }
+
+  function test_filter_row() {
+    $cursor = new class extends Cursor {
+      function filterRow(array $row, $filter): bool {
+        return self::filter_row($row, $filter);
+      }
+    };
+    $row = ["a" => 1, "b" => 2, "c" => 3, "x" => 99];
+    self::assertTrue($cursor->filterRow($row, "a"));
+    self::assertTrue($cursor->filterRow($row, ["a"]));
+    self::assertTrue($cursor->filterRow($row, ["a" => true]));
+    self::assertFalse($cursor->filterRow($row, ["a" => false]));
+    self::assertTrue($cursor->filterRow($row, ["a" => 1]));
+    self::assertFalse($cursor->filterRow($row, ["a" => 2]));
+
+    self::assertFalse($cursor->filterRow($row, "z"));
+    self::assertFalse($cursor->filterRow($row, ["z"]));
+    self::assertFalse($cursor->filterRow($row, ["z" => true]));
+    self::assertTrue($cursor->filterRow($row, ["z" => false]));
+    self::assertFalse($cursor->filterRow($row, ["z" => 1]));
+  }
+
   const SCALARS = [0, 1, 2, 3, 4];
 
   function generator() {
@@ -41,6 +78,15 @@ class CursorTest extends TestCase {
       return cl::all($c);
     });
 
+    $c = new Cursor(null, [
+      "rows" => $this->generator(),
+    ]);
+    self::assertSame([[0], [1], [2], [3], [4]], cl::all($c));
+    self::assertException(Exception::class, function() use ($c) {
+      // pas possible de rewind un générateur
+      return cl::all($c);
+    });
+
     $c = new Cursor(null, [
       "rows_func" => function() {
         return self::SCALARS;