Shingle Token Filter

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A token filter of type shingle that constructs shingles (token n-grams) from a token stream. In other words, it creates combinations of tokens as a single token. For example, the sentence "please divide this sentence into shingles" might be tokenized into shingles "please divide", "divide this", "this sentence", "sentence into", and "into shingles".

This filter handles position increments > 1 by inserting filler tokens (tokens with termtext "_"). It does not handle a position increment of 0.

The following are settings that can be set for a shingle token filter type:

Setting Description

max_shingle_size

The maximum shingle size. Defaults to 2.

min_shingle_size

The minimum shingle size. Defaults to 2.

output_unigrams

If true the output will contain the input tokens (unigrams) as well as the shingles. Defaults to true.

output_unigrams_if_no_shingles

If output_unigrams is false the output will contain the input tokens (unigrams) if no shingles are available. Note if output_unigrams is set to true this setting has no effect. Defaults to false.

token_separator

The string to use when joining adjacent tokens to form a shingle. Defaults to " ".