Bengali analyzer
The built-in bengali analyzer can be applied to a text field using the following command:
PUT /bengali-index
{
"mappings": {
"properties": {
"content": {
"type": "text",
"analyzer": "bengali"
}
}
}
}
Stem exclusion
You can use stem_exclusion with this language analyzer using the following command:
PUT index_with_stem_exclusion_bengali_analyzer
{
"settings": {
"analysis": {
"analyzer": {
"stem_exclusion_bengali_analyzer": {
"type": "bengali",
"stem_exclusion": ["কর্তৃপক্ষ", "অনুমোদন"]
}
}
}
}
}
Bengali analyzer internals
The bengali analyzer is built using the following components:
-
Tokenizer:
standard -
Token filters:
- lowercase
- decimal_digit
- indic_normalization
- normalization (Bengali)
- stop (Bengali)
- keyword
- stemmer (Bengali)
Custom Bengali analyzer
You can create a custom Bengali analyzer using the following command:
PUT /bengali-index
{
"settings": {
"analysis": {
"filter": {
"bengali_stop": {
"type": "stop",
"stopwords": "_bengali_"
},
"bengali_stemmer": {
"type": "stemmer",
"language": "bengali"
},
"bengali_keywords": {
"type": "keyword_marker",
"keywords": []
}
},
"analyzer": {
"bengali_analyzer": {
"type": "custom",
"tokenizer": "standard",
"filter": [
"lowercase",
"decimal_digit",
"indic_normalization",
"bengali_normalization",
"bengali_stop",
"bengali_keywords",
"bengali_stemmer"
]
}
}
}
},
"mappings": {
"properties": {
"content": {
"type": "text",
"analyzer": "bengali_analyzer"
}
}
}
}
Generated tokens
Use the following request to examine the tokens generated using the analyzer:
POST /bengali-index/_analyze
{
"field": "content",
"text": "ছাত্ররা বিশ্ববিদ্যালয়ে পড়াশোনা করে। তাদের নম্বরগুলি ১২৩৪৫৬।"
}
The response contains the generated tokens:
{
"tokens": [
{"token": "ছাত্র","start_offset": 0,"end_offset": 7,"type": "<ALPHANUM>","position": 0},
{"token": "বিসসবিদালয়","start_offset": 8,"end_offset": 23,"type": "<ALPHANUM>","position": 1},
{"token": "পরাসোন","start_offset": 24,"end_offset": 32,"type": "<ALPHANUM>","position": 2},
{"token": "তা","start_offset": 38,"end_offset": 43,"type": "<ALPHANUM>","position": 4},
{"token": "নমমর","start_offset": 44,"end_offset": 53,"type": "<ALPHANUM>","position": 5},
{"token": "123456","start_offset": 54,"end_offset": 60,"type": "<NUM>","position": 6}
]
}