Adding standard analyzer docs (#8528)

* adding standard analyzer docs Signed-off-by: Anton Rubin <[email protected]> * adding further details Signed-off-by: Anton Rubin <[email protected]> * adding more examples Signed-off-by: Anton Rubin <[email protected]> * Doc review Signed-off-by: Fanit Kolchina <[email protected]> * Apply suggestions from code review Co-authored-by: Nathan Bower <[email protected]> Signed-off-by: kolchfa-aws <[email protected]> --------- Signed-off-by: Anton Rubin <[email protected]> Signed-off-by: Fanit Kolchina <[email protected]> Signed-off-by: kolchfa-aws <[email protected]> Co-authored-by: Fanit Kolchina <[email protected]> Co-authored-by: kolchfa-aws <[email protected]> Co-authored-by: Nathan Bower <[email protected]> (cherry picked from commit b81500f) Signed-off-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
opensearch-project · Dec 10, 2024 · 2e209a3 · 2e209a3
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+---
+layout: default
+title: Standard analyzer
+nav_order: 40
+---
+
+# Standard analyzer
+
+The `standard` analyzer is the default analyzer used when no other analyzer is specified. It is designed to provide a basic and efficient approach to generic text processing.
+
+This analyzer consists of the following tokenizers and token filters:
+
+- `standard` tokenizer: Removes most punctuation and splits text on spaces and other common delimiters.
+- `lowercase` token filter: Converts all tokens to lowercase, ensuring case-insensitive matching.
+- `stop` token filter: Removes common stopwords, such as "the", "is", and "and", from the tokenized output.
+
+## Example 
+
+Use the following command to create an index named `my_standard_index` with a `standard` analyzer:
+
+```json
+PUT /my_standard_index
+{
+  "mappings": {
+    "properties": {
+      "my_field": {
+        "type": "text",
+        "analyzer": "standard"  
+      }
+    }
+  }
+}
+```
+{% include copy-curl.html %}
+
+## Parameters
+
+You can configure a `standard` analyzer with the following parameters.
+
+Parameter | Required/Optional | Data type | Description
+:--- | :--- | :--- | :--- 
+`max_token_length` | Optional | Integer | Sets the maximum length of the produced token. If this length is exceeded, the token is split into multiple tokens at the length configured in `max_token_length`. Default is `255`.
+`stopwords` | Optional | String or list of strings | A string specifying a predefined list of stopwords (such as `_english_`) or an array specifying a custom list of stopwords. Default is `_none_`.
+`stopwords_path` | Optional | String | The path (absolute or relative to the config directory) to the file containing a list of stop words.
+
+
+## Configuring a custom analyzer
+
+Use the following command to configure an index with a custom analyzer that is equivalent to the `standard` analyzer:
+
+```json
+PUT /my_custom_index
+{
+  "settings": {
+    "analysis": {
+      "analyzer": {
+        "my_custom_analyzer": {
+          "type": "custom",
+          "tokenizer": "standard",
+          "filter": [
+            "lowercase", 
+            "stop"
+          ]
+        }
+      }
+    }
+  }
+}
+```
+{% include copy-curl.html %}
+
+## Generated tokens
+
+Use the following request to examine the tokens generated using the analyzer:
+
+```json
+POST /my_custom_index/_analyze
+{
+  "analyzer": "my_custom_analyzer",
+  "text": "The slow turtle swims away"
+}
+```
+{% include copy-curl.html %}
+
+The response contains the generated tokens:
+
+```json
+{
+  "tokens": [
+    {"token": "slow","start_offset": 4,"end_offset": 8,"type": "<ALPHANUM>","position": 1},
+    {"token": "turtle","start_offset": 9,"end_offset": 15,"type": "<ALPHANUM>","position": 2},
+    {"token": "swims","start_offset": 16,"end_offset": 21,"type": "<ALPHANUM>","position": 3},
+    {"token": "away","start_offset": 22,"end_offset": 26,"type": "<ALPHANUM>","position": 4}
+  ]
+}
+```