Path Hierarchy Tokenizer

The path_hierarchy tokenizer takes a hierarchical value like a filesystem path, splits on the path separator, and emits a term for each component in the tree.

Example output

POST _analyze
{
  "tokenizer": "path_hierarchy",
  "text": "/one/two/three"
}

The above text would produce the following terms:

[ /one, /one/two, /one/two/three ]

Configuration

The path_hierarchy tokenizer accepts the following parameters:

delimiter

The character to use as the path separator. Defaults to /.

replacement

An optional replacement character to use for the delimiter. Defaults to the delimiter.

buffer_size

The number of characters read into the term buffer in a single pass. Defaults to 1024. The term buffer will grow by this size until all the text has been consumed. It is advisable not to change this setting.

reverse

If set to true, emits the tokens in reverse order. Defaults to false.

skip

The number of initial tokens to skip. Defaults to 0.

Example configuration

In this example, we configure the path_hierarchy tokenizer to split on - characters, and to replace them with /. The first two tokens are skipped:

PUT my_index
{
  "settings": {
    "analysis": {
      "analyzer": {
        "my_analyzer": {
          "tokenizer": "my_tokenizer"
        }
      },
      "tokenizer": {
        "my_tokenizer": {
          "type": "path_hierarchy",
          "delimiter": "-",
          "replacement": "/",
          "skip": 2
        }
      }
    }
  }
}

POST my_index/_analyze
{
  "analyzer": "my_analyzer",
  "text": "one-two-three-four-five"
}

The above example produces the following terms:

[ /three, /three/four, /three/four/five ]

If we were to set reverse to true, it would produce the following:

[ one/two/three/, two/three/, three/ ]