diff --git a/TODO.md b/TODO.md
new file mode 100644
index 0000000..1f00665
--- /dev/null
+++ b/TODO.md
@@ -0,0 +1,8 @@
+# TODO
+
+## schema
+
+* [ ] properties dans ScalarSchema, avec aliases pour notamment "nature" => ""
+* [ ] remplacer IValue et TValue par une classe abstraite Value
+
+-*- coding: utf-8 mode: markdown -*- vim:sw=4:sts=4:et:ai:si:sta:fenc=utf-8:noeol:binary
\ No newline at end of file
diff --git a/doc/schema.md b/doc/schema.md
index 5f3907c..b4f2c3d 100644
--- a/doc/schema.md
+++ b/doc/schema.md
@@ -183,10 +183,10 @@ const VALUE_SCHEMA = [
     "title" => "libellé de la valeur",
     "required" => false,
     "nullable" => true,
-    "desc" => description de la valeur,
+    "desc" => "description de la valeur",
     "name" => "identifiant de la valeur",
     # spécifique à VALUE_SCHEMA
-    "key" => ""chemin de clé de la valeur dans le tableau associatif",
+    "key" => "chemin de clé de la valeur dans le tableau associatif",
   ],
 ];
 ~~~
@@ -199,7 +199,7 @@ const VALUE_SCHEMA = [
     "title" => "libellé de la valeur",
     "required" => false,
     "nullable" => true,
-    "desc" => description de la valeur,
+    "desc" => "description de la valeur",
     "name" => "identifiant de la valeur",
     # spécifique à VALUE_SCHEMA
     "key" => "chemin de clé de la valeur dans le tableau associatif",
diff --git a/src/schema/AssocSchema.php b/src/schema/AssocSchema.php
index 0c8704b..f34afd5 100644
--- a/src/schema/AssocSchema.php
+++ b/src/schema/AssocSchema.php
@@ -38,7 +38,8 @@ class AssocSchema extends Schema {
     $this->definition = $definition;
   }
 
-  function isAssoc(): bool {
+  function isAssoc(?AssocSchema &$assoc=null): bool {
+    $assoc = $this;
     return true;
   }
 }
diff --git a/src/schema/ListSchema.php b/src/schema/ListSchema.php
index 879af16..f4a6bf7 100644
--- a/src/schema/ListSchema.php
+++ b/src/schema/ListSchema.php
@@ -38,7 +38,8 @@ class ListSchema extends Schema {
     $this->definition = $definition;
   }
 
-  function isList(): bool {
+  function isList(?ListSchema &$list=null): bool {
+    $list = $this;
     return true;
   }
 }
diff --git a/src/schema/OldSchema.php b/src/schema/OldSchema.php
index 65e9dc9..8472085 100644
--- a/src/schema/OldSchema.php
+++ b/src/schema/OldSchema.php
@@ -5,21 +5,9 @@ use nur\sery\schema\input\Input;
 use nur\sery\schema\values\AssocValue;
 use nur\sery\schema\values\IValue;
 use nur\sery\schema\values\ScalarValue;
-use nur\sery\schema\values\SeqValue;
+use nur\sery\schema\values\ListValue;
 use nulib\StateException;
 
-#XXX
-# analyze() et [analyzer_func] --> indique ce qu'est la valeur qu'on vérifixe
-#    retourne MISSING (la valeur n'existe pas)
-#             NULL (la valeur existe mais est nulle)
-#             STRING (la valeur est une chaine qu'il faut parser)
-#             INVALID (la valeur n'est pas du bon type et il n'est pas possible de la convertir)
-#             VALID (la valeur est dans le bon type)
-# extract() et [extractor_func] --> si analyze() retourne STRING, extraire la
-#    chaine à parser
-# parse() et [parser_func] --> parser la chaine et retourner la valeur
-# format() et [formatter_func] --> formatter la valeur et retourner une chaine
-
 class OldSchema {
   /**
    * @var bool true si toutes les clés du schéma doivent exister, avec leur
@@ -49,11 +37,11 @@ class OldSchema {
   }
 
   /** retourner true la valeur est un tableau séquentiel */
-  function getSeq(&$value, $key=null, ?SeqValue &$seq=null): bool {
+  function getList(&$value, $key=null, ?ListValue &$list=null): bool {
     if (!$this->isSeq()) return false;
     if ($value instanceof Input) $input = $value;
     else $input = new Input($value);
-    $seq = new SeqValue($input, $this->schema, $key);
+    $list = new ListValue($input, $this->schema, $key);
     return true;
   }
 
@@ -67,9 +55,9 @@ class OldSchema {
   }
 
   function getValue(&$value, $key=null): IValue {
-    if ($this->getScalar($input, $key, $scalar)) return $scalar;
-    elseif ($this->getSeq($input, $key, $seq)) return $seq;
-    elseif ($this->getAssoc($input, $key, $assoc)) return $assoc;
+    if ($this->getScalar($value, $key, $scalar)) return $scalar;
+    elseif ($this->getList($value, $key, $seq)) return $seq;
+    elseif ($this->getAssoc($value, $key, $assoc)) return $assoc;
     else throw StateException::unexpected_state();
   }
 }
diff --git a/src/schema/ScalarSchema.php b/src/schema/ScalarSchema.php
index 21dc011..c74c0f9 100644
--- a/src/schema/ScalarSchema.php
+++ b/src/schema/ScalarSchema.php
@@ -2,8 +2,11 @@
 namespace nur\sery\schema;
 
 use nulib\cl;
+use nur\sery\schema\input\Input;
 use nur\sery\schema\ref\ref_schema;
 use nur\sery\schema\ref\ref_types;
+use nur\sery\schema\values\IValue;
+use nur\sery\schema\values\ScalarValue;
 
 /**
  * Class ScalarSchema
@@ -31,13 +34,7 @@ class ScalarSchema extends Schema {
     "type", "default", "title", "required", "nullable", "desc",
     "analyzer_func", "extractor_func", "parser_func", "normalizer_func", "messages",
     "formatter_func", "format",
-    "", "name",
-  ];
-  const METASCHEMA_INDEXES = [
-    "type" => 0, "default" => 1, "title" => 2, "required" => 3, "nullable" => 4, "desc" => 5,
-    "analyzer_func" => 6, "extractor_func" => 7, "parser_func" => 8, "normalizer_func" => 9, "messages" => 10,
-    "formatter_func" => 11, "format" => 12,
-    "" => 13, "name" => 14,
+    "", "name", "key", "header", "composite",
   ];
 
   /**
@@ -135,6 +132,18 @@ class ScalarSchema extends Schema {
       throw SchemaException::invalid_schema("expected scalar nature");
     }
     $definition[""] = $nature;
+    # name, key, header
+    $name = $definition["name"];
+    $key = $definition["key"];
+    $header = $definition["header"];
+    self::ensure_nstring($name);
+    self::ensure_npkey($key);
+    self::ensure_nstring($header);
+    if ($key === null) $key = $name;
+    if ($header === null) $header = $name;
+    $definition["name"] = $name;
+    $definition["key"] = $key;
+    $definition["header"] = $header;
     # autres éléments
     self::ensure_nstring($definition["title"]);
     self::ensure_bool($definition["required"]);
@@ -146,7 +155,7 @@ class ScalarSchema extends Schema {
     self::ensure_ncallable($definition["normalizer_func"]);
     self::ensure_narray($definition["messages"]);
     self::ensure_ncallable($definition["formatter_func"]);
-    self::ensure_nkey($definition["name"]);
+    self::ensure_nbool($definition["composite"]);
     return $definition;
   }
 
@@ -156,7 +165,14 @@ class ScalarSchema extends Schema {
     $this->definition = $definition;
   }
 
-  function isScalar(): bool {
+  function isScalar(?ScalarSchema &$scalar=null): bool {
+    $scalar = $this;
     return true;
   }
+
+  function getValue(&$value, $key=null): IValue {
+    if ($value instanceof Input) $input = $value;
+    else $input = new Input($value);
+    return new ScalarValue($input, $this, $key);
+  }
 }
diff --git a/src/schema/Schema.php b/src/schema/Schema.php
index 587c52f..1697dff 100644
--- a/src/schema/Schema.php
+++ b/src/schema/Schema.php
@@ -2,6 +2,7 @@
 namespace nur\sery\schema;
 
 use nulib\cl;
+use nur\sery\schema\values\IValue;
 
 abstract class Schema {
   /**
@@ -22,40 +23,52 @@ abstract class Schema {
     return $md;
   }
 
-  protected static function ensure_nstring(&$string): void {
-    if ($string !== null && !is_string($string)) $string = strval($string);
-  }
   protected static function ensure_string(&$string): void {
     if (!is_string($string)) $string = strval($string);
   }
-  protected static function ensure_nbool(&$bool): void {
-    if ($bool !== null && !is_bool($bool)) $bool = boolval($bool);
+  protected static function ensure_nstring(&$string): void {
+    if ($string !== null) self::ensure_string($string);
   }
   protected static function ensure_bool(&$bool): void {
     if (!is_bool($bool)) $bool = boolval($bool);
   }
-  protected static function ensure_ncallable(&$callable): void {
-    if ($callable !== null && !is_callable($callable)) {
-      throw SchemaException::invalid_callable($callable);
-    }
+  protected static function ensure_nbool(&$bool): void {
+    if ($bool !== null) self::ensure_bool($bool);
   }
-  protected static function ensure_narray(&$array): void {
-    if ($array !== null && !is_array($array)) $array = cl::with($array);
+  protected static function ensure_callable(&$callable): void {
+    if (!is_callable($callable)) throw SchemaException::invalid_callable($callable);
+  }
+  protected static function ensure_ncallable(&$callable): void {
+    if ($callable !== null) self::ensure_callable($callable);
   }
   protected static function ensure_array(&$array): void {
     if (!is_array($array)) $array = cl::with($array);
   }
-  protected static function ensure_nkey(&$key): void {
-    if ($key !== null && !is_string($key) && !is_int($key)) $key = strval($key);
+  protected static function ensure_narray(&$array): void {
+    if ($array !== null) self::ensure_array($array);
   }
   protected static function ensure_key(&$key): void {
     if (!is_string($key) && !is_int($key)) $key = strval($key);
   }
-  protected static function ensure_ncontent(&$key): void {
-    if ($key !== null && !is_string($key) && !is_array($key)) $key = strval($key);
+  protected static function ensure_nkey(&$key): void {
+    if ($key !== null) self::ensure_key($key);
   }
-  protected static function ensure_content(&$key): void {
-    if (!is_string($key) && !is_array($key)) $key = strval($key);
+  protected static function ensure_pkey(&$pkey): void {
+    if (!is_string($pkey) && !is_int($pkey) && !is_array($pkey)) $pkey = strval($pkey);
+    if (is_array($pkey)) {
+      foreach ($pkey as &$key) {
+        self::ensure_key($key);
+      }; unset($key);
+    }
+  }
+  protected static function ensure_npkey(&$pkey): void {
+    if ($pkey !== null) self::ensure_pkey($pkey);
+  }
+  protected static function ensure_content(&$content): void {
+    if (!is_string($content) && !is_array($content)) $content = strval($content);
+  }
+  protected static function ensure_ncontent(&$content): void {
+    if ($content !== null) self::ensure_content($content);
   }
 
   /**
@@ -68,9 +81,11 @@ abstract class Schema {
   protected $definition;
 
   /** retourner true si le schéma est de nature tableau associatif */
-  function isAssoc(): bool { return false; }
+  function isAssoc(?AssocSchema &$assoc=null): bool { return false; }
   /** retourner true si le schéma est de nature liste */
-  function isList(): bool { return false; }
+  function isList(?ListSchema &$list=null): bool { return false; }
   /** retourner true si le schéma est de nature scalaire */
-  function isScalar(): bool { return false; }
+  function isScalar(?ScalarSchema &$scalar=null): bool { return false; }
+
+  abstract function getValue(&$value, $key=null): IValue;
 }
diff --git a/src/schema/ref/ref_analyze.php b/src/schema/ref/ref_analyze.php
new file mode 100644
index 0000000..a640ba1
--- /dev/null
+++ b/src/schema/ref/ref_analyze.php
@@ -0,0 +1,22 @@
+<?php
+namespace nur\sery\schema\ref;
+
+class ref_analyze {
+  /** @var int résultat de l'analyse: valeur inexistante */
+  const MISSING = 0;
+
+  /** @var int résultat de l'analyse: valeur nulle */
+  const NULL = 1;
+
+  /** @var int résultat de l'analyse: valeur chaine à parser */
+  const STRING = 2;
+
+  /** @var int résultat de l'analyse: valeur invalide */
+  const INVALID = 3;
+
+  /** @var int résultat de l'analyse: valeur valide mais pas normalisée */
+  const VALID = 4;
+
+  /** @var int résultat de l'analyse: valeur valide normalisée */
+  const NORMALIZED = 5;
+}
diff --git a/src/schema/ref/ref_schema.php b/src/schema/ref/ref_schema.php
index 5744276..1d72ad2 100644
--- a/src/schema/ref/ref_schema.php
+++ b/src/schema/ref/ref_schema.php
@@ -34,7 +34,10 @@ class ref_schema {
     "" => ["array", "scalar", "nature du schéma",
       "" => ["assoc", "schema" => self::NATURE_METASCHEMA],
     ],
-    "name" => ["?key", null, "identifiant de la valeur"],
+    "name" => ["?string", null, "identifiant de la valeur"],
+    "key" => ["?pkey", null, "chemin de clé de la valeur dans un tableau associatif"],
+    "header" => ["?string", null, "nom de l'en-tête s'il faut présenter cette donnée dans un tableau"],
+    "composite" => ["?bool", null, "ce champ fait-il partie d'une valeur composite?"],
   ];
 
   const MESSAGES = [
diff --git a/src/schema/ref/ref_types.php b/src/schema/ref/ref_types.php
index a3733b5..f7e5198 100644
--- a/src/schema/ref/ref_types.php
+++ b/src/schema/ref/ref_types.php
@@ -4,6 +4,7 @@ namespace nur\sery\schema\ref;
 class ref_types {
   const ALIASES = [
     "key" => "string|int",
+    "pkey" => "string|int|array",
     "content" => "string|array",
   ];
 }
diff --git a/src/schema/values/AssocValue.php b/src/schema/values/AssocValue.php
index e6a55ea..1ed2ad2 100644
--- a/src/schema/values/AssocValue.php
+++ b/src/schema/values/AssocValue.php
@@ -5,7 +5,7 @@ class AssocValue implements IValue {
   use TValue;
 
   function isScalar(?ScalarValue &$scalar=null): bool { return false; }
-  function isSeq(?SeqValue &$seq=null): bool { return false; }
+  function isList(?ListValue &$list=null): bool { return false; }
   function isAssoc(?AssocValue &$assoc=null): bool { $assoc = $this; return true; }
 
   function ensureKeys(): bool {
diff --git a/src/schema/values/IValue.php b/src/schema/values/IValue.php
index e5a66f6..478f412 100644
--- a/src/schema/values/IValue.php
+++ b/src/schema/values/IValue.php
@@ -7,8 +7,8 @@ interface IValue {
   /** retourner true si cette valeur est scalaire */
   function isScalar(?ScalarValue &$scalar=null): bool;
 
-  /** retourner true cette valeur est un tableau séquentiel */
-  function isSeq(?SeqValue &$seq=null): bool;
+  /** retourner true cette valeur est une liste */
+  function isList(?ListValue &$list=null): bool;
 
   /** retourner true cette valeur est un tableau associatif */
   function isAssoc(?AssocValue &$assoc=null): bool;
diff --git a/src/schema/values/SeqValue.php b/src/schema/values/ListValue.php
similarity index 76%
rename from src/schema/values/SeqValue.php
rename to src/schema/values/ListValue.php
index c72ca81..e96bc94 100644
--- a/src/schema/values/SeqValue.php
+++ b/src/schema/values/ListValue.php
@@ -1,11 +1,11 @@
 <?php
 namespace nur\sery\schema\values;
 
-class SeqValue implements IValue {
+class ListValue implements IValue {
   use TValue;
 
   function isScalar(?ScalarValue &$scalar=null): bool { return false; }
-  function isSeq(?SeqValue &$seq=null): bool { $seq = $this; return true; }
+  function isList(?ListValue &$list=null): bool { $list = $this; return true; }
   function isAssoc(?AssocValue &$assoc=null): bool { return false; }
 
   function ensureKeys(): bool {
diff --git a/src/schema/values/Result.php b/src/schema/values/Result.php
index 0e052e1..87cafe6 100644
--- a/src/schema/values/Result.php
+++ b/src/schema/values/Result.php
@@ -23,6 +23,7 @@ class Result {
     $this->result = $result;
   }
 
+  /** @var array  */
   protected $result;
 
   function __get($name) {
diff --git a/src/schema/values/ScalarValue.php b/src/schema/values/ScalarValue.php
index 02fe4aa..2ca3dba 100644
--- a/src/schema/values/ScalarValue.php
+++ b/src/schema/values/ScalarValue.php
@@ -1,21 +1,26 @@
 <?php
 namespace nur\sery\schema\values;
 
+use nur\sery\schema\ScalarSchema;
 use nur\sery\schema\types\IType;
 
 class ScalarValue implements IValue {
   use TValue;
 
-  /** @var ?Result résultat de l'analyse de la valeur */
-  protected ?Result $result;
+  /** @var ScalarSchema schéma de cette valeur */
+  protected $schema;
 
-  function __construct(&$value, array $schema, $key=null, bool $verifix=true) {
+  /** @var ?Result résultat de l'analyse de la valeur */
+  protected $result;
+
+  function __construct(&$value, ScalarSchema $schema, $key=null, bool $verifix=true) {
     $this->schema = $schema;
     $this->reset($value, $key, $verifix);
+    #XXX résoudre les type dans reset()?
   }
 
   function isScalar(?ScalarValue &$scalar=null): bool { $scalar = $this; return true; }
-  function isSeq(?SeqValue &$seq=null): bool { return false; }
+  function isList(?ListValue &$list=null): bool { return false; }
   function isAssoc(?AssocValue &$assoc=null): bool { return false; }
 
   function get($default=null) {
@@ -36,7 +41,7 @@ class ScalarValue implements IValue {
   protected $type;
 
   function type(): IType {
-    if ($this->type === null) $this->type = $this->md()->getType($this->key);
+    if ($this->type === null) $this->type = $this->schema->getType($this->key);
     return $this->type;
   }
 
diff --git a/src/schema/values/TValue.php b/src/schema/values/TValue.php
index 37d15de..d2a52d6 100644
--- a/src/schema/values/TValue.php
+++ b/src/schema/values/TValue.php
@@ -4,16 +4,6 @@ namespace nur\sery\schema\values;
 use nur\sery\schema\OldSchema;
 
 trait TValue {
-  /** @var array schéma normalisé de cette valeur */
-  protected array $schema;
-
-  /** @var OldSchema */
-  protected OldSchema $md;
-
-  function md(): OldSchema {
-    return OldSchema::new($this->md, $this->schema, true);
-  }
-
   /** @var mixed valeur ou référence d'un tableau contenant la valeur */
   protected $value;
 
diff --git a/tests/schema/ScalarSchemaTest.php b/tests/schema/ScalarSchemaTest.php
index 40cdd2a..f8e15e3 100644
--- a/tests/schema/ScalarSchemaTest.php
+++ b/tests/schema/ScalarSchemaTest.php
@@ -20,6 +20,9 @@ class ScalarSchemaTest extends TestCase {
     "format" => null,
     "" => ["scalar"],
     "name" => null,
+    "key" => null,
+    "header" => null,
+    "composite" => null,
   ];
 
   static function schema(array $schema): array {