ES5.0A2 Type keyword and Keyword analyzer

Is it possible to do something like this with the new keyword type?

PUT book
  "settings": {
    "analysis": {
      "analyzer": {
        "code": {
          "type": "custom",
          "filter": ["lowercase","asciifolding"]
  "mappings": {
    "book": {
      "properties": {
        "tags": {
          "analyzer": "code"

Note: the applied token filters do not split into multiple terms

Hi Gerald,

We would like to implement something like this, but this is not possible yet. I don't think it will make it into 5.0 but hopefully it will be implemented in one of the 5.x releases.

For reference: