elasticsearch/docs/reference/analysis/tokenizers/pathhierarchy-tokenizer.asciidoc

[[analysis-pathhierarchy-tokenizer]]
=== 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.

[float]
=== Example output

[source,console]
---------------------------
POST _analyze
{
  "tokenizer": "path_hierarchy",
  "text": "/one/two/three"
}
---------------------------

/////////////////////

[source,console-result]
----------------------------
{
  "tokens": [
    {
      "token": "/one",
      "start_offset": 0,
      "end_offset": 4,
      "type": "word",
      "position": 0
    },
    {
      "token": "/one/two",
      "start_offset": 0,
      "end_offset": 8,
      "type": "word",
      "position": 0
    },
    {
      "token": "/one/two/three",
      "start_offset": 0,
      "end_offset": 14,
      "type": "word",
      "position": 0
    }
  ]
}
----------------------------

/////////////////////



The above text would produce the following terms:

[source,text]
---------------------------
[ /one, /one/two, /one/two/three ]
---------------------------

[float]
=== Configuration

The `path_hierarchy` tokenizer accepts the following parameters:

[horizontal]
`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`.

[float]
=== 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:

[source,console]
----------------------------
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"
}
----------------------------

/////////////////////

[source,console-result]
----------------------------
{
  "tokens": [
    {
      "token": "/three",
      "start_offset": 7,
      "end_offset": 13,
      "type": "word",
      "position": 0
    },
    {
      "token": "/three/four",
      "start_offset": 7,
      "end_offset": 18,
      "type": "word",
      "position": 0
    },
    {
      "token": "/three/four/five",
      "start_offset": 7,
      "end_offset": 23,
      "type": "word",
      "position": 0
    }
  ]
}
----------------------------

/////////////////////


The above example produces the following terms:

[source,text]
---------------------------
[ /three, /three/four, /three/four/five ]
---------------------------

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

[source,text]
---------------------------
[ one/two/three/, two/three/, three/ ]
---------------------------

[float]
=== Detailed Examples
See <<analysis-pathhierarchy-tokenizer-examples, detailed examples here>>.