Reverse token filteredit
Reverses each token in a stream. For example, you can use the reverse filter
to change cat to tac.
Reversed tokens are useful for suffix-based searches,
such as finding words that end in -ion or searching file names by their
extension.
This filter uses Lucene’s ReverseStringFilter.
Exampleedit
The following analyze API request uses the reverse
filter to reverse each token in quick fox jumps:
GET _analyze
{
"tokenizer" : "standard",
"filter" : ["reverse"],
"text" : "quick fox jumps"
}
The filter produces the following tokens:
[ kciuq, xof, spmuj ]
Add to an analyzeredit
The following create index API request uses the
reverse filter to configure a new
custom analyzer.
PUT reverse_example
{
"settings" : {
"analysis" : {
"analyzer" : {
"whitespace_reverse" : {
"tokenizer" : "whitespace",
"filter" : ["reverse"]
}
}
}
}
}