-
Notifications
You must be signed in to change notification settings - Fork 507
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
- Loading branch information
Showing
170 changed files
with
5,931 additions
and
987 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
|
@@ -7,3 +7,4 @@ Gemfile.lock | |
*.iml | ||
.jekyll-cache | ||
.project | ||
vendor/bundle |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,135 @@ | ||
--- | ||
layout: default | ||
title: ASCII folding | ||
parent: Token filters | ||
nav_order: 20 | ||
--- | ||
|
||
# ASCII folding token filter | ||
|
||
The `asciifolding` token filter converts non-ASCII characters to their closest ASCII equivalents. For example, *é* becomes *e*, *ü* becomes *u*, and *ñ* becomes *n*. This process is known as *transliteration*. | ||
|
||
|
||
The `asciifolding` token filter offers a number of benefits: | ||
|
||
- **Enhanced search flexibility**: Users often omit accents or special characters when entering queries. The `asciifolding` token filter ensures that such queries still return relevant results. | ||
- **Normalization**: Standardizes the indexing process by ensuring that accented characters are consistently converted to their ASCII equivalents. | ||
- **Internationalization**: Particularly useful for applications including multiple languages and character sets. | ||
|
||
While the `asciifolding` token filter can simplify searches, it may also lead to the loss of specific information, particularly if the distinction between accented and non-accented characters in the dataset is significant. | ||
{: .warning} | ||
|
||
## Parameters | ||
|
||
You can configure the `asciifolding` token filter using the `preserve_original` parameter. Setting this parameter to `true` keeps both the original token and its ASCII-folded version in the token stream. This can be particularly useful when you want to match both the original (with accents) and the normalized (without accents) versions of a term in a search query. Default is `false`. | ||
|
||
## Example | ||
|
||
The following example request creates a new index named `example_index` and defines an analyzer with the `asciifolding` filter and `preserve_original` parameter set to `true`: | ||
|
||
```json | ||
PUT /example_index | ||
{ | ||
"settings": { | ||
"analysis": { | ||
"filter": { | ||
"custom_ascii_folding": { | ||
"type": "asciifolding", | ||
"preserve_original": true | ||
} | ||
}, | ||
"analyzer": { | ||
"custom_ascii_analyzer": { | ||
"type": "custom", | ||
"tokenizer": "standard", | ||
"filter": [ | ||
"lowercase", | ||
"custom_ascii_folding" | ||
] | ||
} | ||
} | ||
} | ||
} | ||
} | ||
``` | ||
{% include copy-curl.html %} | ||
|
||
## Generated tokens | ||
|
||
Use the following request to examine the tokens generated using the analyzer: | ||
|
||
```json | ||
POST /example_index/_analyze | ||
{ | ||
"analyzer": "custom_ascii_analyzer", | ||
"text": "Résumé café naïve coördinate" | ||
} | ||
``` | ||
{% include copy-curl.html %} | ||
|
||
The response contains the generated tokens: | ||
|
||
```json | ||
{ | ||
"tokens": [ | ||
{ | ||
"token": "resume", | ||
"start_offset": 0, | ||
"end_offset": 6, | ||
"type": "<ALPHANUM>", | ||
"position": 0 | ||
}, | ||
{ | ||
"token": "résumé", | ||
"start_offset": 0, | ||
"end_offset": 6, | ||
"type": "<ALPHANUM>", | ||
"position": 0 | ||
}, | ||
{ | ||
"token": "cafe", | ||
"start_offset": 7, | ||
"end_offset": 11, | ||
"type": "<ALPHANUM>", | ||
"position": 1 | ||
}, | ||
{ | ||
"token": "café", | ||
"start_offset": 7, | ||
"end_offset": 11, | ||
"type": "<ALPHANUM>", | ||
"position": 1 | ||
}, | ||
{ | ||
"token": "naive", | ||
"start_offset": 12, | ||
"end_offset": 17, | ||
"type": "<ALPHANUM>", | ||
"position": 2 | ||
}, | ||
{ | ||
"token": "naïve", | ||
"start_offset": 12, | ||
"end_offset": 17, | ||
"type": "<ALPHANUM>", | ||
"position": 2 | ||
}, | ||
{ | ||
"token": "coordinate", | ||
"start_offset": 18, | ||
"end_offset": 28, | ||
"type": "<ALPHANUM>", | ||
"position": 3 | ||
}, | ||
{ | ||
"token": "coördinate", | ||
"start_offset": 18, | ||
"end_offset": 28, | ||
"type": "<ALPHANUM>", | ||
"position": 3 | ||
} | ||
] | ||
} | ||
``` | ||
|
||
|
Oops, something went wrong.