ICU tokenizer

Tokenizes text into words on word boundaries, as defined in UAX #29: Unicode Text Segmentation. It behaves much like the standard tokenizer, but adds better support for some Asian languages by using a dictionary-based approach to identify words in Thai, Lao, Chinese, Japanese, and Korean, and using custom rules to break Myanmar and Khmer text into syllables.

 PUT icu_sample { "settings": { "index": { "analysis": { "analyzer": { "my_icu_analyzer": { "tokenizer": "icu_tokenizer" } } } } } } 

You can customize the icu-tokenizer behavior by specifying per-script rule files, see the RBBI rules syntax reference for a more detailed explanation.

To add icu tokenizer rules, set the rule_files settings, which should contain a comma-separated list of code:rulefile pairs in the following format: four-letter ISO 15924 script code, followed by a colon, then a rule file name. Rule files are placed ES_HOME/config directory.

As a demonstration of how the rule files can be used, save the following user file to $ES_HOME/config/KeywordTokenizer.rbbi:

 .+ {200}; 

Then create an analyzer to use this rule file as follows:

 PUT icu_sample { "settings": { "index": { "analysis": { "tokenizer": { "icu_user_file": { "type": "icu_tokenizer", "rule_files": "Latn:KeywordTokenizer.rbbi" } }, "analyzer": { "my_analyzer": { "type": "custom", "tokenizer": "icu_user_file" } } } } } } GET icu_sample/_analyze { "analyzer": "my_analyzer", "text": "Elasticsearch. Wow!" } 

The above analyze request returns the following:

 { "tokens": [ { "token": "Elasticsearch. Wow!", "start_offset": 0, "end_offset": 19, "type": "<ALPHANUM>", "position": 0 } ] }