diff --git a/src/schema/Result.php b/src/schema/Result.php
index 46f08ee..21c2b7f 100644
--- a/src/schema/Result.php
+++ b/src/schema/Result.php
@@ -2,9 +2,6 @@
 namespace nur\sery\wip\schema;
 
 use IteratorAggregate;
-use nur\sery\wip\schema\_assoc\AssocResult;
-use nur\sery\wip\schema\_list\ListResult;
-use nur\sery\wip\schema\_scalar\ScalarResult;
 use Throwable;
 
 /**
@@ -37,10 +34,6 @@ abstract class Result implements IteratorAggregate {
     $this->reset();
   }
 
-  function isAssoc(?AssocResult &$result=null): bool { return false; }
-  function isList(?ListResult &$result=null): bool { return false; }
-  function isScalar(?ScalarResult &$result=null): bool { return false; }
-
   /**
    * Obtenir la liste des clés valides pour les valeurs accessibles via cet
    * objet
diff --git a/src/schema/Schema.php b/src/schema/Schema.php
index 4d1a422..aef756d 100644
--- a/src/schema/Schema.php
+++ b/src/schema/Schema.php
@@ -98,18 +98,18 @@ abstract class Schema implements ArrayAccess {
     return false;
   }
 
-  protected static function _normalize_definition(&$definition, $definitionKey=null): void {
+  protected static function _normalize_definition(&$definition, $definitionKey=null, ?array $natureMetaschema=null): void {
     if (!is_array($definition)) $definition = [$definition];
     # s'assurer que toutes les clés existent avec leur valeur par défaut
     $index = 0;
-    foreach (array_keys(ref_schema::SCALAR_METASCHEMA) as $key) {
+    foreach (array_keys(ref_schema::VALUE_METASCHEMA) as $key) {
       if (!array_key_exists($key, $definition)) {
         if (array_key_exists($index, $definition)) {
           $definition[$key] = $definition[$index];
           unset($definition[$index]);
           $index++;
         } else {
-          $definition[$key] = ref_schema::SCALAR_METASCHEMA[$key][1];
+          $definition[$key] = ref_schema::VALUE_METASCHEMA[$key][1];
         }
       }
     }
@@ -161,6 +161,12 @@ abstract class Schema implements ArrayAccess {
     # nature
     $nature = $definition[""];
     tarray::ensure_array($nature);
+    $natureMetaschema ??= ref_schema::NATURE_METASCHEMA;
+    foreach (array_keys($natureMetaschema) as $key) {
+      if (!array_key_exists($key, $nature)) {
+        $nature[$key] = $natureMetaschema[$key][1];
+      }
+    }
     $definition[""] = $nature;
     # name, pkey, header
     $name = $definition["name"];
diff --git a/src/schema/TODO.md b/src/schema/TODO.md
index b41abbe..745781f 100644
--- a/src/schema/TODO.md
+++ b/src/schema/TODO.md
@@ -2,8 +2,8 @@
 
 * faire PropertyAccess
 * si l'argument de Input() est un objet, utiliser PropertyAccess au lieu de KeyAccess
-* possibilité de forcer l'un ou l'autre
-* ensureKeys() et orderKeys() se fait au niveau de access
+  * possibilité de forcer l'un ou l'autre (paramètre type=value|array|object)
+* ensureKeys() et orderKeys() se fait au niveau de access (ou input?)
 
 * valeurs composite/computed
   * analyse / vérification de la valeur complète après calcul du résultat, si
diff --git a/src/schema/Wrapper.php b/src/schema/Wrapper.php
index 7d6361f..4cf6a9a 100644
--- a/src/schema/Wrapper.php
+++ b/src/schema/Wrapper.php
@@ -23,14 +23,17 @@ abstract class Wrapper implements ArrayAccess, IteratorAggregate {
     $this->context->resetParams($params);
   }
 
-  protected function afterModify(?array $params, bool $reset=true): void {
+  protected function resetContext($resetSelectedKey): void {
     $context = $this->context;
-    if ($reset) {
-      $context->type = null;
-      $context->result->reset();
-      $context->analyzed = false;
-      $context->normalized = false;
-    }
+    $context->type = null;
+    $context->result->reset();
+    $context->analyzed = false;
+    $context->normalized = false;
+  }
+
+  protected function afterModify(?array $params, $resetSelectedKey=false): void {
+    $context = $this->context;
+    $this->resetContext($resetSelectedKey);
     if ($params["analyze"] ?? $context->analyze) {
       $this->analyze($params);
     }
@@ -51,7 +54,15 @@ abstract class Wrapper implements ArrayAccess, IteratorAggregate {
    * @param ?array $params paramètres spécifique à cet appel, qui peuvent être
    * différent des paramètres par défaut
    */
-  abstract function reset(&$value, $valueKey=null, ?array $params=null): self;
+  function reset(&$value, $valueKey=null, ?array $params=null): Wrapper {
+    $context = $this->context;
+    if ($value instanceof Input) $input = $value;
+    else $input = $this->newInput($value);
+    $context->input = $input;
+    $context->valueKey = $valueKey;
+    $this->afterModify($params, true);
+    return $this;
+  }
 
   /** analyser la valeur */
   abstract protected function _analyze(?array $params): int;
@@ -119,50 +130,50 @@ abstract class Wrapper implements ArrayAccess, IteratorAggregate {
    * cette fonction doit être appelée après {@link set()} ou {@link unset()} et
    * après que le wrapper aie été sélectionné avec {@link select()}
    */
-  function getResult(): Result {
+  function getResult($key=false): Result {
     return $this->context->result;
   }
 
   /** retourner true si la valeur existe */
-  function isPresent(): bool {
-    return $this->context->result->present;
+  function isPresent($key=false): bool {
+    return $this->getResult()->present;
   }
 
   /** retourner le type associé à la valeur */
-  function getType(): IType {
+  function getType($key=false): IType {
     return $this->context->type;
   }
 
   /** retourner true si la valeur est disponible */
-  function isAvailable(): bool {
-    return $this->context->result->available;
+  function isAvailable($key=false): bool {
+    return $this->getResult()->available;
   }
 
   /** retourner true si la valeur est valide */
-  function isValid(): bool {
-    return $this->context->result->valid;
+  function isValid($key=false): bool {
+    return $this->getResult()->valid;
   }
 
   /** retourner true si la valeur est dans sa forme normalisée */
-  function isNormalized(): bool {
-    return $this->context->result->normalized;
+  function isNormalized($key=false): bool {
+    return $this->getResult()->normalized;
   }
 
 
-  function get($default=null) {
+  function get($default=null, $key=false) {
     $context = $this->context;
-    if ($context->result->available) return $context->input->get($context->valueKey);
-    else return $default;
+    if (!$context->result->available) return $default;
+    return $context->input->get($context->valueKey);
   }
 
-  function set($value, ?array $params=null): self {
+  function set($value, ?array $params=null, $key=false): self {
     $context = $this->context;
     $context->input->set($value, $context->valueKey);
     $this->afterModify($params);
     return $this;
   }
 
-  function unset(?array $params=null): self {
+  function unset(?array $params=null, $key=false): self {
     $context = $this->context;
     $context->input->unset($context->valueKey);
     $this->afterModify($params);
@@ -186,7 +197,7 @@ abstract class Wrapper implements ArrayAccess, IteratorAggregate {
   }
 
   /** formatter la valeur pour affichage */
-  function format($format=null): string {
+  function format($format=null, $key=false): string {
     return $this->_format($this->context, $format);
   }
 
@@ -198,14 +209,14 @@ abstract class Wrapper implements ArrayAccess, IteratorAggregate {
   }
 
   function offsetGet($offset) {
-    return $this->select($offset)->get();
+    return $this->get(null, $offset);
   }
 
   function offsetSet($offset, $value): void {
-    $this->select($offset)->set($value);
+    $this->set($value, null, $offset);
   }
 
   function offsetUnset($offset): void {
-    $this->select($offset)->unset();
+    $this->unset(null, $offset);
   }
 }
diff --git a/src/schema/WrapperContext.php b/src/schema/WrapperContext.php
index 6e523e4..d144939 100644
--- a/src/schema/WrapperContext.php
+++ b/src/schema/WrapperContext.php
@@ -12,6 +12,7 @@ class WrapperContext {
     $this->valueKey = $valueKey;
     $this->origValue = null;
     $this->value = null;
+    $this->selectedKey = null;
     $this->type = null;
     $this->result = null;
   }
diff --git a/src/schema/_assoc/AssocResult.php b/src/schema/_assoc/AssocResult.php
deleted file mode 100644
index 76a2a74..0000000
--- a/src/schema/_assoc/AssocResult.php
+++ /dev/null
@@ -1,50 +0,0 @@
-<?php
-namespace nur\sery\wip\schema\_assoc;
-
-use nulib\ValueException;
-use nur\sery\wip\schema\Result;
-
-class AssocResult extends Result {
-  function __construct(AssocWrapperContext $context) {
-    $this->context = $context;
-    parent::__construct();
-  }
-
-  function isAssoc(?AssocResult &$result=null): bool { $result = $this; return true;}
-
-  protected AssocWrapperContext $context;
-
-  function getKeys(): array {
-    return $this->context->keys;
-  }
-
-  protected Result $result;
-
-  function select($key): AssocResult {
-    $context = $this->context;
-    if ($key === null) {
-      $this->result = $context->arrayResult;
-      return $this;
-    }
-    $wrapper = $context->keyWrappers[$key] ?? null;
-    if ($wrapper === null) throw ValueException::invalid_key($key);
-    $this->result = $wrapper->getResult();
-    return $this;
-  }
-
-  function reset(): void {
-    $context = $this->context;
-    $context->arrayResult->reset();
-    foreach ($context->keyWrappers as $wrapper) {
-      $wrapper->getResult()->reset();
-    }
-  }
-
-  function __get(string $name) {
-    return $this->result[$name];
-  }
-
-  function __set(string $name, $value): void {
-    $this->result[$name] = $value;
-  }
-}
diff --git a/src/schema/_assoc/AssocSchema.php b/src/schema/_assoc/AssocSchema.php
index d7bb88e..e49d794 100644
--- a/src/schema/_assoc/AssocSchema.php
+++ b/src/schema/_assoc/AssocSchema.php
@@ -11,8 +11,11 @@ use nur\sery\wip\schema\Wrapper;
  * Class AssocSchema
  */
 class AssocSchema extends Schema {
-  /** @var array meta-schema d'un schéma de nature tableau associatif */
-  const METASCHEMA = ref_schema::ASSOC_METASCHEMA;
+  //const METASCHEMA = ref_schema::VALUE_METASCHEMA;
+  //const NATURE_METASCHEMA = [
+  //  ...ref_schema::NATURE_METASCHEMA,
+  //  ...ref_schema::ASSOC_NATURE_METASCHEMA,
+  //];
 
   /**
    * indiquer si $definition est une définition de schéma de nature tableau
@@ -37,7 +40,8 @@ class AssocSchema extends Schema {
         "schema" => $definition,
       ];
     }
-    self::_normalize_definition($definition, $definitionKey);
+    $natureMetaschema = array_merge(ref_schema::NATURE_METASCHEMA, ref_schema::ASSOC_NATURE_METASCHEMA);
+    self::_normalize_definition($definition, $definitionKey, $natureMetaschema);
     self::_ensure_nature($definition, "assoc", "array");
     return $definition;
   }
@@ -83,9 +87,9 @@ class AssocSchema extends Schema {
   function getWrapper(&$value=null, $valueKey=null, ?array $params=null, ?Wrapper &$wrapper=null): AssocWrapper {
     # si pas de valeur ni de wrapper, pas de vérification et donc pas d'exception
     # cf le code similaire dans ScalarWrapper::__construct()
-    $verifix = $value !== null || $wrapper !== null;
+    $dontNormalize = $value === null && $wrapper === null;
     if (!($wrapper instanceof AssocWrapper)) $wrapper = $this->newWrapper();
     if ($params !== null) $wrapper->resetParams($params);
-    return $wrapper->reset($value, $valueKey, $verifix);
+    return $wrapper->reset($value, $valueKey, $dontNormalize? ["normalize" => false]: null);
   }
 }
diff --git a/src/schema/_assoc/AssocWrapper.php b/src/schema/_assoc/AssocWrapper.php
index f7a3a38..029d5b7 100644
--- a/src/schema/_assoc/AssocWrapper.php
+++ b/src/schema/_assoc/AssocWrapper.php
@@ -4,12 +4,13 @@ namespace nur\sery\wip\schema\_assoc;
 use nulib\ValueException;
 use nur\sery\wip\schema\_scalar\ScalarResult;
 use nur\sery\wip\schema\input\Input;
+use nur\sery\wip\schema\Result;
 use nur\sery\wip\schema\types\IType;
 use nur\sery\wip\schema\Wrapper;
 use nur\sery\wip\schema\WrapperContext;
 
 class AssocWrapper extends Wrapper {
-  function __construct(AssocSchema $schema, &$array=null, $arrayKey=null, ?array $params=null) {
+  function __construct(AssocSchema $schema, &$value=null, $valueKey=null, ?array $params=null) {
     $keys = $schema->getKeys();
     $keyTypes = [];
     $keyWrappers = [];
@@ -22,16 +23,17 @@ class AssocWrapper extends Wrapper {
     $context->keys = $keys;
     $context->keyTypes = $keyTypes;
     $context->keyWrappers = $keyWrappers;
-    $context->result = new AssocResult($context);
+    $context->result = $context->arrayResult;
 
-    $throw = $context->throw;
-    if ($array !== null && $throw === null) {
-      # Si $value est null, ne pas lancer d'exception, parce qu'on considère que
-      # c'est une initialisation sans conséquences
-      $throw = true;
-    }
+    # calculer manuellemet throw ici parce que WrapperContext le met à true par
+    # défaut. on veut pouvoir mettre temporairement throw à false si jamais il
+    # n'est pas spécifié par l'utilisateur
+    $throw = $params["throw"] ?? null;
+    # Si $value est null, ne pas lancer d'exception, parce qu'on considère que
+    # c'est une initialisation sans conséquences
+    if ($throw === null && $value !== null) $throw = true;
     $context->throw = $throw ?? false;
-    $this->reset($array, $arrayKey);
+    $this->reset($value, $valueKey);
     $context->throw = $throw ?? true;
   }
 
@@ -40,35 +42,103 @@ class AssocWrapper extends Wrapper {
   /** @var AssocWrapperContext  */
   protected WrapperContext $context;
 
-  function reset(&$array, $arrayKey=null, ?array $params=null): Wrapper {
-    if ($array instanceof Input) $input = $array;
-    else $input = $this->newInput($array);
+  protected function resetContext($resetSelectedKey): void {
     $context = $this->context;
-    $context->input = $input;
-    $context->valueKey = $arrayKey;
-    $this->afterModify($params);
-    return $this;
+    $context->arrayResult->reset();
+    foreach ($context->keyWrappers as $wrapper) {
+      $wrapper->getResult()->reset();
+    }
+    $context->analyzed = false;
+    $context->normalized = false;
+    if ($resetSelectedKey) {
+      $context->selectedKey = null;
+      $context->type = $context->arrayType;
+      $context->result = $context->arrayResult;
+    }
   }
 
   function getKeys(): array {
     return $this->context->keys;
   }
 
-  /** @param string|int|null $key */
-  function select($key=null): Wrapper {
-    #XXX il faut que context contiennent les informations pour la clé sélectionnée
-    if ($key === null) return $this;
-    $wrapper = $this->context->keyWrappers[$key] ?? null;
+  protected function _getWrapper($key): Wrapper {
+    $wrapper = $context->keyWrappers[$key] ?? null;
     if ($wrapper === null) throw ValueException::invalid_key($key);
     return $wrapper;
   }
 
-  function isNormalized(): bool {
-    return $this->context->result->normalized;
+  /** @param string|int|null $key */
+  function select($key=null): Wrapper {
+    $context = $this->context;
+    if ($key === null) {
+      $context->selectedKey = null;
+      $context->type = $context->arrayType;
+      $context->result = $context->arrayResult;
+      return $this;
+    }
+    $wrapper = $this->_getWrapper($key);
+    $context->selectedKey = $key;
+    $context->type = $wrapper->getType();
+    $context->result = $wrapper->getResult();
+    return $wrapper;
   }
 
-  function ensureKeys(): bool {
+  protected function _analyze(?array $params): int {
+    return -1;
   }
-  function orderKeys(): bool {
+
+  protected function _normalize(?array $params): bool {
+    return false;
+  }
+
+  function getResult($key=false): Result {
+    if ($key === false) return $this->context->result;
+    elseif ($key === null) return $this->context->arrayResult;
+    else return $this->_getWrapper($key)->getResult();
+  }
+
+  function getType($key=false): IType {
+    if ($key === false) return $this->context->type;
+    elseif ($key === null) return $this->context->arrayType;
+    else return $this->_getWrapper($key)->getType();
+  }
+
+  function get($default=null, $key=false) {
+    $context = $this->context;
+    if (!$context->arrayResult->available) return $default;
+    if ($key === false) $key = $context->selectedKey;
+    if ($key === null) return $context->input->get($context->valueKey);
+    else return $this->_getWrapper($key)->get($default);
+  }
+
+  function set($value, ?array $params=null, $key=false): Wrapper {
+    $context = $this->context;
+    if ($key === false) $key = $context->selectedKey;
+    if ($key === null) {
+      $context->input->set($value, $context->valueKey);
+      $this->afterModify($params);
+    } else {
+      $this->_getWrapper($key)->set($value);
+    }
+    return $this;
+  }
+
+  function unset(?array $params=null, $key=false): Wrapper {
+    $context = $this->context;
+    if ($key === false) $key = $context->selectedKey;
+    if ($key === null) {
+      $context->input->unset($context->valueKey);
+      $this->afterModify($params);
+    } else {
+      $this->_getWrapper($key)->unset();
+    }
+    return $this;
+  }
+
+  function format($format=null, $key=false): string {
+    $context = $this->context;
+    if ($key === false) $key = $context->selectedKey;
+    if ($key === null) return $this->_format($context, $format);
+    else return $this->_getWrapper($key)->format($format);
   }
 }
diff --git a/src/schema/_assoc/AssocWrapperContext.php b/src/schema/_assoc/AssocWrapperContext.php
index ed25436..44fee29 100644
--- a/src/schema/_assoc/AssocWrapperContext.php
+++ b/src/schema/_assoc/AssocWrapperContext.php
@@ -2,13 +2,22 @@
 namespace nur\sery\wip\schema\_assoc;
 
 use nur\sery\wip\schema\_scalar\ScalarResult;
+use nur\sery\wip\schema\input\Input;
+use nur\sery\wip\schema\Schema;
 use nur\sery\wip\schema\types\IType;
 use nur\sery\wip\schema\Wrapper;
 use nur\sery\wip\schema\WrapperContext;
 
 class AssocWrapperContext extends WrapperContext {
+  function __construct(Schema $schema, ?Input $input, $valueKey, ?array $params) {
+    parent::__construct($schema, $input, $valueKey, $params);
+    $this->arrayType = null;
+    $this->arrayResult = null;
+  }
+
+  public ?IType $arrayType;
   /** résultat de l'analyse du tableau */
-  public ScalarResult $arrayResult;
+  public ?ScalarResult $arrayResult;
 
   /** liste des clés valides */
   public array $keys;
diff --git a/src/schema/_scalar/ScalarSchema.php b/src/schema/_scalar/ScalarSchema.php
index 1621e5b..d726ebb 100644
--- a/src/schema/_scalar/ScalarSchema.php
+++ b/src/schema/_scalar/ScalarSchema.php
@@ -1,6 +1,7 @@
 <?php
 namespace nur\sery\wip\schema\_scalar;
 
+use nulib\cl;
 use nulib\ref\schema\ref_schema;
 use nulib\ValueException;
 use nur\sery\wip\schema\Schema;
@@ -10,8 +11,11 @@ use nur\sery\wip\schema\Wrapper;
  * Class ScalarSchema
  */
 class ScalarSchema extends Schema {
-  /** @var array meta-schema d'un schéma de nature scalaire */
-  const METASCHEMA = ref_schema::SCALAR_METASCHEMA;
+  //const METASCHEMA = ref_schema::VALUE_METASCHEMA;
+  //const NATURE_METASCHEMA = [
+  //  ...ref_schema::NATURE_METASCHEMA,
+  //  ...ref_schema::SCALAR_NATURE_METASCHEMA,
+  //];
 
   /**
    * indiquer si $definition est une définition de schéma scalaire que
@@ -45,7 +49,8 @@ class ScalarSchema extends Schema {
   }
 
   static function normalize_definition($definition, $definitionKey=null): array {
-    self::_normalize_definition($definition, $definitionKey);
+    $natureMetaschema = array_merge(ref_schema::NATURE_METASCHEMA, ref_schema::SCALAR_NATURE_METASCHEMA);
+    self::_normalize_definition($definition, $definitionKey, $natureMetaschema);
     self::_ensure_nature($definition, "scalar");
     return $definition;
   }
diff --git a/src/schema/_scalar/ScalarWrapper.php b/src/schema/_scalar/ScalarWrapper.php
index 3a33684..6f48a41 100644
--- a/src/schema/_scalar/ScalarWrapper.php
+++ b/src/schema/_scalar/ScalarWrapper.php
@@ -4,7 +4,6 @@ namespace nur\sery\wip\schema\_scalar;
 use nulib\php\func;
 use nulib\ref\schema\ref_analyze;
 use nulib\ValueException;
-use nur\sery\wip\schema\input\Input;
 use nur\sery\wip\schema\types;
 use nur\sery\wip\schema\types\IType;
 use nur\sery\wip\schema\Wrapper;
@@ -13,6 +12,7 @@ use nur\sery\wip\schema\WrapperContext;
 /**
  * Class ScalarWrapper
  *
+ * @method ScalarWrapper reset()
  * @method ScalarResult getResult()
  * @method self set()
  * @method self unset()
@@ -38,16 +38,6 @@ class ScalarWrapper extends Wrapper {
 
   protected WrapperContext $context;
 
-  function reset(&$value, $valueKey=null, ?array $params=null): Wrapper {
-    $context = $this->context;
-    if ($value instanceof Input) $input = $value;
-    else $input = $this->newInput($value);
-    $context->input = $input;
-    $context->valueKey = $valueKey;
-    $this->afterModify($params);
-    return $this;
-  }
-
   function getKeys(): array {
     return ScalarSchema::KEYS;
   }
diff --git a/tests/wip/schema/_assoc/AssocSchemaTest.php b/tests/wip/schema/_assoc/AssocSchemaTest.php
index 384f5d6..a082855 100644
--- a/tests/wip/schema/_assoc/AssocSchemaTest.php
+++ b/tests/wip/schema/_assoc/AssocSchemaTest.php
@@ -7,7 +7,14 @@ use nur\sery\wip\schema\_scalar\ScalarSchemaTest;
 
 class AssocSchemaTest extends TestCase {
   const NULL_SCHEMA = [
-    "" => ["assoc"],
+    "" => [
+      "assoc",
+      "compute_func" => null,
+      "validate_func" => null,
+      "ensure_array" => false,
+      "ensure_keys" => true,
+      "ensure_order" => true,
+    ],
     "schema" => null,
     "type" => [null],
     "default" => null,
diff --git a/tests/wip/schema/_scalar/ScalarSchemaTest.php b/tests/wip/schema/_scalar/ScalarSchemaTest.php
index a5b6cee..5742fb8 100644
--- a/tests/wip/schema/_scalar/ScalarSchemaTest.php
+++ b/tests/wip/schema/_scalar/ScalarSchemaTest.php
@@ -19,7 +19,11 @@ class ScalarSchemaTest extends TestCase {
     "messages" => null,
     "formatter_func" => null,
     "format" => null,
-    "" => ["scalar"],
+    "" => [
+      "scalar",
+      "compute_func" => null,
+      "validate_func" => null,
+    ],
     "schema" => null,
     "name" => null,
     "pkey" => null,