diff --git a/README.md b/README.md
index eee5634..a4372c8 100644
--- a/README.md
+++ b/README.md
@@ -19,8 +19,11 @@ git checkout dev82
 
 prel -C
 
-commit="$(git log --grep="Init changelog . version ${version}p82" --format=%H)"
+commit="$(git log --grep="Init changelog . version ${version}p82" --format=%H)" &&
+echo "commit=$commit"
+
 git checkout dev74
+
 git cherry-pick "$commit"
 pp -a
 ~~~
diff --git a/bash/src/pman.sh b/bash/src/pman.sh
index 4a2d928..094b269 100644
--- a/bash/src/pman.sh
+++ b/bash/src/pman.sh
@@ -426,7 +426,7 @@ EOF
 $(qvals echo "$(awk <"$changelog" '
 BEGIN { p = 0 }
 p == 0 && $0 == "" { p = 1; next }
-p == 1 { gsub(/\$/, "\\$", $0); print }
+p == 1 { print }
 ')") >CHANGES.md
 git add CHANGES.md
 EOF
diff --git a/php/src/A.php b/php/src/A.php
index 253592b..75f0284 100644
--- a/php/src/A.php
+++ b/php/src/A.php
@@ -177,6 +177,14 @@ class A {
     return $pvalue;
   }
 
+  static final function shift(?array &$dest, int $count=1, $default=null) {
+    if ($dest === null) return null;
+    $values = array_slice($dest, 0, $count);
+    $dest = array_slice($dest, $count);
+    if ($values === []) return $default;
+    else return $count == 1? $values[0]: $values;
+  }
+
   static final function pop(&$dest, $key, $default=null) {
     if ($dest === null) return $default;
     self::ensure_narray($dest);
diff --git a/php/src/cv.php b/php/src/cv.php
index 3bd8773..fd61a8e 100644
--- a/php/src/cv.php
+++ b/php/src/cv.php
@@ -86,6 +86,12 @@ class cv {
     $b = $tmp;
   }
 
+  /** cloner une valeur */
+  static final function clone($value) {
+    if (is_object($value)) $value = clone $value;
+    return $value;
+  }
+
   #############################################################################
 
   /** mettre à jour $dest avec $value si $cond($value) est vrai */
@@ -197,19 +203,29 @@ class cv {
   }
 
   /**
-   * retourner [$bool, $string, $array] initialisés chacun en fonction du type
+   * retourner [$bool, $scalar, $array] initialisés chacun en fonction du type
    * de $value.
    *
    * @throws ValueException si $value n'est d'aucun de ces types
    */
   static final function check_bsa($value, ?string $prefix=null, bool $throw_exception=true): array {
     $bool = is_bool($value)? $value : null;
-    $string = is_string($value)? $value : null;
+    $scalar = !is_bool($value) && is_scalar($value)? $value : null;
     $array = is_array($value)? $value : null;
-    if ($bool === null && $string === null && $array === null && $throw_exception) {
+    if ($bool === null && $scalar === null && $array === null && $throw_exception) {
       throw ValueException::invalid_kind($value, "value", $prefix);
     } else {
-      return [$bool, $string, $array];
+      return [$bool, $scalar, $array];
+    }
+  }
+
+  static final function subclass_of($value, $class): bool {
+    if (is_string($value)) {
+      return $value === $class || is_subclass_of($value, $class);
+    } elseif (is_object($value)) {
+      return $value instanceof $class;
+    } else {
+      return false;
     }
   }
 
diff --git a/php/src/db/Capacitor.php b/php/src/db/Capacitor.php
index 0fee8b5..5551f1b 100644
--- a/php/src/db/Capacitor.php
+++ b/php/src/db/Capacitor.php
@@ -1,6 +1,7 @@
 <?php
 namespace nulib\db;
 
+use nulib\cl;
 use nulib\php\func;
 use nulib\ValueException;
 use Traversable;
@@ -168,6 +169,13 @@ class Capacitor implements ITransactor {
     return $this->storage->_delete($this->channel, $filter, $func, $args);
   }
 
+  function dbUpdate(array $update) {
+    return $this->storage->db()->exec(cl::merge([
+      "update",
+      "table" => $this->getTableName(),
+    ], $update));
+  }
+
   function close(): void {
     $this->storage->close();
   }
diff --git a/php/src/db/CapacitorChannel.php b/php/src/db/CapacitorChannel.php
index c7265bb..4349e4b 100644
--- a/php/src/db/CapacitorChannel.php
+++ b/php/src/db/CapacitorChannel.php
@@ -13,7 +13,9 @@ class CapacitorChannel implements ITransactor {
 
   const TABLE_NAME = null;
 
-  const COLUMN_DEFINITIONS = null;
+  protected function COLUMN_DEFINITIONS(): ?array {
+    return static::COLUMN_DEFINITIONS;
+  } const COLUMN_DEFINITIONS = null;
 
   const PRIMARY_KEYS = null;
 
@@ -28,19 +30,17 @@ class CapacitorChannel implements ITransactor {
   static function verifix_name(?string &$name, ?string &$tableName=null): void {
     if ($name !== null) {
       $name = strtolower($name);
-      if ($tableName === null) {
-        $tableName = str_replace("-", "_", $name) . "_channel";
-      }
+      $tableName ??= str_replace("-", "_", $name) . "_channel";
     } else {
       $name = static::class;
       if ($name === self::class) {
         $name = "default";
-        if ($tableName === null) $tableName = "default_channel";
+        $tableName ??= "default_channel";
       } else {
         $name = preg_replace('/^.*\\\\/', "", $name);
         $name = preg_replace('/Channel$/', "", $name);
         $name = lcfirst($name);
-        if ($tableName === null) $tableName = str::camel2us($name);
+        $tableName ??= str::camel2us($name);
         $name = strtolower($name);
       }
     }
@@ -63,7 +63,7 @@ class CapacitorChannel implements ITransactor {
     $this->useCache = static::USE_CACHE;
     $this->setup = false;
     $this->created = false;
-    $columnDefinitions = cl::withn(static::COLUMN_DEFINITIONS);
+    $columnDefinitions = $this->COLUMN_DEFINITIONS();
     $primaryKeys = cl::withn(static::PRIMARY_KEYS);
     $migration = cl::withn(static::MIGRATION);
     $lastMkey = 1;
@@ -482,6 +482,10 @@ class CapacitorChannel implements ITransactor {
     return $this->capacitor->delete($filter, $func, $args);
   }
 
+  function dbUpdate(array $update) {
+    return $this->capacitor->dbUpdate($update);
+  }
+
   function close(): void {
     $this->capacitor->close();
   }
diff --git a/php/src/db/CapacitorStorage.php b/php/src/db/CapacitorStorage.php
index ba00c07..9d4cdb1 100644
--- a/php/src/db/CapacitorStorage.php
+++ b/php/src/db/CapacitorStorage.php
@@ -3,7 +3,6 @@ namespace nulib\db;
 
 use nulib\cl;
 use nulib\db\_private\_migration;
-use nulib\db\cache\cache;
 use nulib\php\func;
 use nulib\ValueException;
 use Traversable;
diff --git a/php/src/db/cache/CacheChannel.php b/php/src/db/cache/CacheChannel.php
deleted file mode 100644
index b1f8619..0000000
--- a/php/src/db/cache/CacheChannel.php
+++ /dev/null
@@ -1,116 +0,0 @@
-<?php
-namespace nulib\db\cache;
-
-use nulib\cl;
-use nulib\db\CapacitorChannel;
-use nulib\php\time\DateTime;
-use nulib\php\time\Delay;
-
-class CacheChannel extends CapacitorChannel {
-  /** @var int durée de vie par défaut du cache */
-  const DURATION = "1D"; // jusqu'au lendemain
-
-  const INCLUDES = null;
-
-  const EXCLUDES = null;
-
-  const COLUMN_DEFINITIONS = [
-    "group_id" => "varchar(64) not null",
-    "id" => "varchar(64) not null",
-    "date_start" => "datetime",
-    "duration_" => "text",
-    "primary key (group_id, id)",
-  ];
-
-  static function get_cache_ids($id): array {
-    if (is_array($id)) {
-      $keys = array_keys($id);
-      if (array_key_exists("group_id", $id)) $groupIdKey = "group_id";
-      else $groupIdKey = $keys[1] ?? null;
-      $groupId = $id[$groupIdKey] ?? "";
-      if (array_key_exists("id", $id)) $idKey = "id";
-      else $idKey = $keys[0] ?? null;
-      $id = $id[$idKey] ?? "";
-    } else {
-      $groupId = "";
-    }
-    if (preg_match('/^(.*\\\\)?([^\\\\]+)$/', $groupId, $ms)) {
-      # si le groupe est une classe, faire un hash du package pour limiter la
-      # longueur du groupe
-      [$package, $groupId] = [$ms[1], $ms[2]];
-      $package = substr(md5($package), 0, 4);
-      $groupId = "${groupId}_$package";
-    }
-    return ["group_id" => $groupId, "id" => $id];
-  }
-
-  function __construct(?string $duration=null, ?string $name=null) {
-    parent::__construct($name);
-    $this->duration = $duration ?? static::DURATION;
-    $this->includes = static::INCLUDES;
-    $this->excludes = static::EXCLUDES;
-  }
-
-  protected string $duration;
-
-  protected ?array $includes;
-
-  protected ?array $excludes;
-
-  function getItemValues($item): ?array {
-    return cl::merge(self::get_cache_ids($item), [
-      "item" => null,
-    ]);
-  }
-
-  function onCreate($item, array $values, ?array $alwaysNull, ?string $duration=null): ?array {
-    $now = new DateTime();
-    $duration ??= $this->duration;
-    return [
-      "date_start" => $now,
-      "duration" => new Delay($duration, $now),
-    ];
-  }
-
-  function onUpdate($item, array $values, array $pvalues, ?string $duration=null): ?array {
-    $now = new DateTime();
-    $duration ??= $this->duration;
-    return [
-      "date_start" => $now,
-      "duration" => new Delay($duration, $now),
-    ];
-  }
-
-  function shouldUpdate($id, bool $noCache=false): bool {
-    if ($noCache) return true;
-
-    $cacheIds = self::get_cache_ids($id);
-    $groupId = $cacheIds["group_id"];
-    if ($groupId) {
-      $includes = $this->includes;
-      $shouldInclude = $includes !== null && in_array($groupId, $includes);
-      $excludes = $this->excludes;
-      $shouldExclude = $excludes !== null && in_array($groupId, $excludes);
-      if (!$shouldInclude || $shouldExclude) return true;
-    }
-
-    $found = false;
-    $expired = false;
-    $this->each($cacheIds,
-      function($item, $values) use (&$found, &$expired) {
-        $found = true;
-        $expired = $values["duration"]->isElapsed();
-      });
-    return !$found || $expired;
-  }
-
-  function setCached($id, ?string $duration=null): void {
-    $cacheIds = self::get_cache_ids($id);
-    $this->charge($cacheIds, null, [$duration]);
-  }
-
-  function resetCached($id) {
-    $cacheIds = self::get_cache_ids($id);
-    $this->delete($cacheIds);
-  }
-}
diff --git a/php/src/db/cache/RowsChannel.php b/php/src/db/cache/RowsChannel.php
deleted file mode 100644
index a3f7055..0000000
--- a/php/src/db/cache/RowsChannel.php
+++ /dev/null
@@ -1,51 +0,0 @@
-<?php
-namespace nulib\db\cache;
-
-use Closure;
-use IteratorAggregate;
-use nulib\cl;
-use nulib\db\CapacitorChannel;
-use Traversable;
-
-class RowsChannel extends CapacitorChannel implements IteratorAggregate {
-  const COLUMN_DEFINITIONS = [
-    "key" => "varchar(128) primary key not null",
-    "all_values" => "mediumtext",
-  ];
-
-  function __construct($id, callable $builder, ?string $duration=null) {
-    $this->cacheIds = $cacheIds = CacheChannel::get_cache_ids($id);
-    $this->builder = Closure::fromCallable($builder);
-    $this->duration = $duration;
-    $name = "{$cacheIds["group_id"]}-{$cacheIds["id"]}";
-    parent::__construct($name);
-  }
-
-  protected array $cacheIds;
-
-  protected Closure $builder;
-
-  protected ?string $duration = null;
-
-  function getItemValues($item): ?array {
-    $key = array_keys($item)[0];
-    $row = $item[$key];
-    return [
-      "key" => $key,
-      "item" => $row,
-      "all_values" => implode(" ", cl::filter_n(cl::with($row))),
-    ];
-  }
-
-  function getIterator(): Traversable {
-    $cm = cache::get();
-    if ($cm->shouldUpdate($this->cacheIds)) {
-      $this->capacitor->reset();
-      foreach (($this->builder)() as $key => $row) {
-        $this->charge([$key => $row]);
-      }
-      $cm->setCached($this->cacheIds, $this->duration);
-    }
-    return $this->discharge(false);
-  }
-}
diff --git a/php/src/db/cache/cache.php b/php/src/db/cache/cache.php
deleted file mode 100644
index 401fb19..0000000
--- a/php/src/db/cache/cache.php
+++ /dev/null
@@ -1,37 +0,0 @@
-<?php
-namespace nulib\db\cache;
-
-use nulib\db\Capacitor;
-use nulib\db\CapacitorStorage;
-use nulib\db\sqlite\SqliteStorage;
-
-class cache {
-  protected static ?CapacitorStorage $storage = null;
-
-  static function set_storage(CapacitorStorage $storage): CapacitorStorage {
-    return self::$storage = $storage;
-  }
-
-  protected static function get_storage(): CapacitorStorage {
-    return self::$storage ??= new SqliteStorage("");
-  }
-
-  protected static ?CacheChannel $channel = null;
-
-  static function set(?CacheChannel $channel): CacheChannel {
-    $channel ??= new CacheChannel();
-    new Capacitor(self::get_storage(), $channel);
-    return self::$channel = $channel;
-  }
-
-  static function get(): CacheChannel {
-    if (self::$channel !== null) return self::$channel;
-    else return self::set(null);
-  }
-
-  static function new(?RowsChannel $channel, $id=null, ?callable $builder=null): RowsChannel {
-    $channel ??= new RowsChannel($id, $builder);
-    new Capacitor(self::get_storage(), $channel);
-    return $channel;
-  }
-}
diff --git a/php/src/db/pgsql/Pgsql.php b/php/src/db/pgsql/Pgsql.php
index efc84a4..f765666 100644
--- a/php/src/db/pgsql/Pgsql.php
+++ b/php/src/db/pgsql/Pgsql.php
@@ -30,7 +30,11 @@ class Pgsql implements IDatabase {
 
 
   protected const OPTIONS = [
-    "persistent" => true,
+    # XXX désactiver les connexions persistantes par défaut
+    # pour réactiver par défaut, il faudrait vérifier la connexion à chaque fois
+    # qu'elle est ouverte avec un "select 1". en effet, l'expérience jusqu'ici
+    # est que la première connexion après un long timeout échoue
+    "persistent" => false,
     "force_new" => false,
     "serial_support" => true,
   ];
diff --git a/php/src/file/IReader.php b/php/src/file/IReader.php
index 36a351b..fa96f7d 100644
--- a/php/src/file/IReader.php
+++ b/php/src/file/IReader.php
@@ -40,4 +40,6 @@ interface IReader extends _IFile {
   function unserialize(?array $options=null, bool $close=true, bool $alreadyLocked=false);
 
   function copyTo(IWriter $dest, bool $closeWriter=false, bool $closeReader=true): void;
+
+  function setCsvFlavour(?string $flavour): void;
 }
diff --git a/php/src/file/Stream.php b/php/src/file/Stream.php
index 65216ee..c1d7496 100644
--- a/php/src/file/Stream.php
+++ b/php/src/file/Stream.php
@@ -299,8 +299,8 @@ class Stream extends AbstractIterator implements IReader, IWriter {
 
   /** retourner le contenu du fichier sous forme de chaine */
   function getContents(bool $close=true, bool $alreadyLocked=false): string {
-    $useLocking = $this->useLocking;
-    if ($useLocking && !$alreadyLocked) $this->lock(LOCK_SH);
+    $useLocking = $this->useLocking && !$alreadyLocked;
+    if ($useLocking) $this->lock(LOCK_SH);
     try {
       return IOException::ensure_valid(stream_get_contents($this->fd), $this->throwOnError);
     } finally {
@@ -380,7 +380,9 @@ class Stream extends AbstractIterator implements IReader, IWriter {
   /** @throws IOException */
   function ftruncate(int $size=0, bool $rewind=true): self {
     $fd = $this->getResource();
-    IOException::ensure_valid(ftruncate($fd, $size), $this->throwOnError);
+    $r = ftruncate($fd, $size);
+    $this->stat = null;
+    IOException::ensure_valid($r, $this->throwOnError);
     if ($rewind) rewind($fd);
     return $this;
   }
@@ -390,6 +392,7 @@ class Stream extends AbstractIterator implements IReader, IWriter {
     $fd = $this->getResource();
     if ($length === null) $r = fwrite($fd, $data);
     else $r = fwrite($fd, $data, $length);
+    $this->stat = null;
     return IOException::ensure_valid($r, $this->throwOnError);
   }
 
@@ -403,9 +406,13 @@ class Stream extends AbstractIterator implements IReader, IWriter {
         $line[] = strval($col);
       }
       $line = implode($sep, $line);
-      IOException::ensure_valid(fwrite($fd, "$line\n"), $this->throwOnError);
+      $r = fwrite($fd, "$line\n");
+      $this->stat = null;
+      IOException::ensure_valid($r, $this->throwOnError);
     } else {
-      IOException::ensure_valid(fputcsv($fd, $row, $params[0], $params[1], $params[2]), $this->throwOnError);
+      $r = fputcsv($fd, $row, $params[0], $params[1], $params[2]);
+      $this->stat = null;
+      IOException::ensure_valid($r, $this->throwOnError);
     }
   }
 
@@ -471,8 +478,8 @@ class Stream extends AbstractIterator implements IReader, IWriter {
   }
 
   function putContents(string $contents, bool $close=true, bool $alreadyLocked=false): void {
-    $useLocking = $this->useLocking;
-    if ($useLocking && !$alreadyLocked) $this->lock(LOCK_EX);
+    $useLocking = $this->useLocking && !$alreadyLocked;
+    if ($useLocking) $this->lock(LOCK_EX);
     try {
       $this->fwrite($contents);
     } finally {
diff --git a/php/src/file/csv/CsvReader.php b/php/src/file/csv/CsvReader.php
index d923976..317fda0 100644
--- a/php/src/file/csv/CsvReader.php
+++ b/php/src/file/csv/CsvReader.php
@@ -2,7 +2,9 @@
 namespace nulib\file\csv;
 
 use nulib\file;
+use nulib\file\_IFile;
 use nulib\file\FileReader;
+use nulib\file\IReader;
 use nulib\file\tab\AbstractReader;
 use nulib\file\tab\TAbstractReader;
 
@@ -20,7 +22,12 @@ class CsvReader extends AbstractReader {
   protected ?string $inputEncoding;
 
   function getIterator() {
-    $reader = new FileReader(file::fix_dash($this->input));
+    $input = $this->input;
+    if ($input instanceof IReader) {
+      $reader = $input;
+    } else {
+      $reader = new FileReader(file::fix_dash($input));
+    }
     $inputEncoding = $this->inputEncoding;
     if ($inputEncoding !== null) {
       $reader->appendFilter("convert.iconv.$inputEncoding.utf-8");
diff --git a/php/src/php/func.php b/php/src/php/func.php
index f2d2883..fcec77b 100644
--- a/php/src/php/func.php
+++ b/php/src/php/func.php
@@ -478,11 +478,17 @@ class func {
   }
 
   static function with($func, ?array $args=null, bool $strict=true): self {
+    if ($func instanceof self) return $func;
     $func = self::_with($func, $args, $strict, $reason);
     if ($func !== null) return $func;
     throw self::not_a_callable($func, $reason);
   }
 
+  static function withn($func, ?array $args=null, bool $strict=true): ?self {
+    if ($func === null) return null;
+    else return self::with($func, $args, $strict);
+  }
+
   static function ensure($func, ?array $args=null, bool $strict=true): self {
     $func = self::with($func, $args, $strict);
     if (!$func->isBound()) {
diff --git a/php/src/php/time/DateInterval.php b/php/src/php/time/DateInterval.php
index c9ca935..210e6ba 100644
--- a/php/src/php/time/DateInterval.php
+++ b/php/src/php/time/DateInterval.php
@@ -29,7 +29,7 @@ class DateInterval extends \DateInterval {
   }
 
   function __construct($duration) {
-    if (is_int($duration)) $duration = "PT${duration}S";
+    if (is_numeric($duration)) $duration = "PT${duration}S";
     if ($duration instanceof \DateInterval) {
       $this->y = $duration->y;
       $this->m = $duration->m;
diff --git a/php/src/php/time/Delay.php b/php/src/php/time/Delay.php
index 14a5307..4afcf37 100644
--- a/php/src/php/time/Delay.php
+++ b/php/src/php/time/Delay.php
@@ -3,6 +3,7 @@ namespace nulib\php\time;
 
 use DateTimeInterface;
 use InvalidArgumentException;
+use nulib\ValueException;
 
 /**
  * Class Delay: une durée jusqu'à un moment destination. le moment destination
@@ -115,6 +116,10 @@ class Delay {
     $this->repr = $repr;
   }
 
+  function __clone() {
+    $this->dest = clone $this->dest;
+  }
+
   function __serialize(): array {
     return [$this->dest, $this->repr];
   }
@@ -130,7 +135,7 @@ class Delay {
   }
 
   function addDuration($duration) {
-    if (is_int($duration) && $duration < 0) {
+    if (is_numeric($duration) && $duration < 0) {
       $this->dest->sub(DateInterval::with(-$duration));
     } else {
       $this->dest->add(DateInterval::with($duration));
@@ -138,7 +143,7 @@ class Delay {
   }
 
   function subDuration($duration) {
-    if (is_int($duration) && $duration < 0) {
+    if (is_numeric($duration) && $duration < 0) {
       $this->dest->add(DateInterval::with(-$duration));
     } else {
       $this->dest->sub(DateInterval::with($duration));