NOTE: You are looking at documentation for an older release. For the latest information, see the current release documentation.
ICU Normalization Character Filter
editICU Normalization Character Filter
editNormalizes characters as explained
here.
It registers itself as the icu_normalizer character filter, which is
available to all indices without any further configuration. The type of
normalization can be specified with the name parameter, which accepts nfc,
nfkc, and nfkc_cf (default). Set the mode parameter to decompose to
convert nfc to nfd or nfkc to nfkd respectively:
Which letters are normalized can be controlled by specifying the
unicodeSetFilter parameter, which accepts a
UnicodeSet.
Here are two examples, the default usage and a customised character filter:
PUT icu_sample
{
"settings": {
"index": {
"analysis": {
"analyzer": {
"nfkc_cf_normalized": {
"tokenizer": "icu_tokenizer",
"char_filter": [
"icu_normalizer"
]
},
"nfd_normalized": {
"tokenizer": "icu_tokenizer",
"char_filter": [
"nfd_normalizer"
]
}
},
"char_filter": {
"nfd_normalizer": {
"type": "icu_normalizer",
"name": "nfc",
"mode": "decompose"
}
}
}
}
}
}