code:

$data = array('a' => 1, 'b' => null, 'c' => 3); var_dump($data); var_dump( $string = Spyc::yamlDump($data) ); var_dump( $data = Spyc::YAMLLoadString($string) );

Here is the output:

array(3) { ["a"]=> int(1) ["b"]=> NULL ["c"]=> int(3) } string(17) "--- a: 1 b: c: 3 " array(3) { ["a"]=> int(1) ["b"]=> string(0) "" ["c"]=> int(3) }

I would expect $data to end up how it started but b gets changed from null to ''.

The null can be represented as null or ~ and in fact both are handled find in Spyc::YAMLLoadString so I am confused as to why they are not handled in the exporter.

I think a simple fix for this is to go into _dumpNode and make a small change:

  $value  = $this->_doFolding($value,$indent);
  if (is_bool($value)) {
    $value = ($value) ? "true" : "false";
  }
  elseif (is_null($value)) { //
    $value = "null";             // this is what I added
  }                                         //

Ok, i realize why that isn't going to work and you'd have to do some refactoring to handle that case. Off to try the symphony implementation...

The bug with handling null values is now fixed in the latest SVN version. Thanks for the bug report!