This documentation contains work-in-progress information for future Elastic Stack and Cloud releases. Use the version selector to view supported release docs. It also contains some Elastic Cloud serverless information. Check out our serverless docs for more details.

« Stemmer token filter Stop token filter »

› › ›

Stemmer override token filter

edit

Stemmer override token filter

edit

Overrides stemming algorithms, by applying a custom mapping, then protecting these terms from being modified by stemmers. Must be placed before any stemming filters.

Rules are mappings in the form of token1[, ..., tokenN] => override.

Setting	Description
`rules`	A list of mapping rules to use.
`rules_path`	A path (either relative to `config` location, or absolute) to a list of mappings.

Here is an example:

resp = client.indices.create(
    index="my-index-000001",
    settings={
        "analysis": {
            "analyzer": {
                "my_analyzer": {
                    "tokenizer": "standard",
                    "filter": [
                        "lowercase",
                        "custom_stems",
                        "porter_stem"
                    ]
                }
            },
            "filter": {
                "custom_stems": {
                    "type": "stemmer_override",
                    "rules_path": "analysis/stemmer_override.txt"
                }
            }
        }
    },
)
print(resp)

response = client.indices.create(
  index: 'my-index-000001',
  body: {
    settings: {
      analysis: {
        analyzer: {
          my_analyzer: {
            tokenizer: 'standard',
            filter: [
              'lowercase',
              'custom_stems',
              'porter_stem'
            ]
          }
        },
        filter: {
          custom_stems: {
            type: 'stemmer_override',
            rules_path: 'analysis/stemmer_override.txt'
          }
        }
      }
    }
  }
)
puts response

const response = await client.indices.create({
  index: "my-index-000001",
  settings: {
    analysis: {
      analyzer: {
        my_analyzer: {
          tokenizer: "standard",
          filter: ["lowercase", "custom_stems", "porter_stem"],
        },
      },
      filter: {
        custom_stems: {
          type: "stemmer_override",
          rules_path: "analysis/stemmer_override.txt",
        },
      },
    },
  },
});
console.log(response);

PUT /my-index-000001
{
  "settings": {
    "analysis": {
      "analyzer": {
        "my_analyzer": {
          "tokenizer": "standard",
          "filter": [ "lowercase", "custom_stems", "porter_stem" ]
        }
      },
      "filter": {
        "custom_stems": {
          "type": "stemmer_override",
          "rules_path": "analysis/stemmer_override.txt"
        }
      }
    }
  }
}

Where the file looks like:

running, runs => run

stemmer => stemmer

You can also define the overrides rules inline:

resp = client.indices.create(
    index="my-index-000001",
    settings={
        "analysis": {
            "analyzer": {
                "my_analyzer": {
                    "tokenizer": "standard",
                    "filter": [
                        "lowercase",
                        "custom_stems",
                        "porter_stem"
                    ]
                }
            },
            "filter": {
                "custom_stems": {
                    "type": "stemmer_override",
                    "rules": [
                        "running, runs => run",
                        "stemmer => stemmer"
                    ]
                }
            }
        }
    },
)
print(resp)

response = client.indices.create(
  index: 'my-index-000001',
  body: {
    settings: {
      analysis: {
        analyzer: {
          my_analyzer: {
            tokenizer: 'standard',
            filter: [
              'lowercase',
              'custom_stems',
              'porter_stem'
            ]
          }
        },
        filter: {
          custom_stems: {
            type: 'stemmer_override',
            rules: [
              'running, runs => run',
              'stemmer => stemmer'
            ]
          }
        }
      }
    }
  }
)
puts response

const response = await client.indices.create({
  index: "my-index-000001",
  settings: {
    analysis: {
      analyzer: {
        my_analyzer: {
          tokenizer: "standard",
          filter: ["lowercase", "custom_stems", "porter_stem"],
        },
      },
      filter: {
        custom_stems: {
          type: "stemmer_override",
          rules: ["running, runs => run", "stemmer => stemmer"],
        },
      },
    },
  },
});
console.log(response);

PUT /my-index-000001
{
  "settings": {
    "analysis": {
      "analyzer": {
        "my_analyzer": {
          "tokenizer": "standard",
          "filter": [ "lowercase", "custom_stems", "porter_stem" ]
        }
      },
      "filter": {
        "custom_stems": {
          "type": "stemmer_override",
          "rules": [
            "running, runs => run",
            "stemmer => stemmer"
          ]
        }
      }
    }
  }
}

« Stemmer token filter Stop token filter »