Problem when looping over arrays with objects

gistfile1

# Adding a tweet with an array of tags and an array with weights for each detected language.
curl -XPUT http://localhost:9201/twitter/tweet/1 -d ' 
{
"tags" : ["foo", "bar"],
"weights" : [{"lang":"eng", "weight":0.97}, {"lang":"swe", "weight":0.03}]
}
'
{"ok":true,"_index":"twitter2","_type":"tweet","_id":"1","_version":1}

--------


# Looping over the tags-array works as expcted and sets the tmp-variable to 'loop ok'
curl -XGET http://localhost:9201/twitter/tweet/_search?pretty=true -d '
{
    "query": {
                "match_all": {}
    },
     "script_fields" : {
	"foo" : {
		"script":"tmp = ''; for(item : doc['tags'].values){tmp = 'loop ok'}; return tmp"
	}
    }
}
'

Returns:

{
  "took" : 4,
  "timed_out" : false,
  "_shards" : {
    "total" : 5,
    "successful" : 5,
    "failed" : 0
  },
  "hits" : {
    "total" : 1,
    "max_score" : 1.0,
    "hits" : [ {
      "_index" : "twitter",
      "_type" : "tweet",
      "_id" : "1",
      "_score" : 1.0,
      "fields" : {
        "foo" : "loop ok"
      }
    } ]
  }
}


---------
# Looping over the array named weights, which is an array of objects, does not work
curl -XGET http://localhost:9201/twitter/tweet/_search?pretty=true -d '

{
    "query": {
                "match_all": {}
    },
     "script_fields" : {
	"foo" : {
		"script":"tmp = ''; for(item : doc['weights'].values){tmp = 'loop ok'}; return tmp"
	}
    }
}
'

Returns :
{
  "took" : 11,
  "timed_out" : false,
  "_shards" : {
    "total" : 5,
    "successful" : 4,
    "failed" : 1,
    "failures" : [ {
      "status" : 500,
      "reason" : "CompileException[[Error: No field found for [weights]]\n[Near : {... tmp = ''; for(item : doc['weig ....}]\n             ^\n[Line: 1, Column: 1]]; nested: ElasticSearchIllegalArgumentException[No field found for [weights]]; "
    } ]
  },
  "hits" : {
    "total" : 1,
    "max_score" : 1.0,
    "hits" : [ ]
  }
}


The stack trace can be found here: https://gist.github.com/1414981

-------


Mapping for this index and type:
curl -XGET http://localhost:9201/twitter/tweet/_mapping?pretty=true

returns this:

{
  "tweet" : {
    "properties" : {
      "tags" : {
        "type" : "string"
      },
      "weights" : {
        "dynamic" : "true",
        "properties" : {
          "weight" : {
            "type" : "double"
          },
          "lang" : {
            "type" : "string"
          }
        }
      }
    }
  }
}

FYI: I get the same result with foreach...