# Array Regex Mask (ArrayRegexMaskGenerator)

The [Array Regex Mask](https://docs.tonic.ai/app/generation/generators/generator-reference/array-regex-mask) generator is a version of the Regex Mask generator that can be used for array values.

It uses regular expressions to parse strings and replace specified substrings with the output of specified generators. The parts of the string to replace are specified inside unnamed top-level capture groups.

## Link object structure <a href="#generator-api-array-regex-mask-link-object" id="generator-api-array-regex-mask-link-object"></a>

In the Array Regex Mask generator, each link object identifies a regular expression and the generators to apply to the resulting capture groups.

The generator does not in itself support consistency or allow you to configure differential privacy.

The `metadata` object for each link object is populated from the [`RegexMaskMetadata`](https://app.tonic.ai/apidocs/index.html#/models/RegexMaskMetadata) object, and includes:

* Whether to replace all matches or only the first match.
* The regular expression used to identify the capture groups to replace.
* The list of generator types to apply to each capture group. The first sub-generator is applied to the first capture group, the second generator to the second group, and so on.
* In the `captureGroupMetadata` object, the configuration for each generator in `captureGroupSubGenerators`. The sequence of the entries in `captureGroupMetadata` must match the sequence of the generators in `captureGroupSubGenerators`.

```json
{
  "schema": "string",
  "table": "string",
  "column": "string",
  "metadata": {
    "generatorId": "ArrayRegexMaskGenerator",
    "presetId": "ArrayRegexMaskGenerator",
    "replaceAllMatches": boolean,
    "pattern": "string",
    "captureGroupMetadata": [
      {
              //Metadata for a capture group generator
      }
    ]
  }
}
```

## Example replacement <a href="#generator-api-array-regex-mask-replacement" id="generator-api-array-regex-mask-replacement"></a>

The following example provides a regex pattern that produces a single capture group.

For that capture group, the Constant generator is applied. The capture group value is replaced with `test_value`.

```json
{
  "name": "character_col",
  "schema": "public",
  "table": "my_table",
  "links": [
    {
      "schema": "public",
      "table": "my_table",
      "column": "array_value",
      "metadata": {
        "generatorId": "ArrayRegexMaskGenerator",
        "presetId": "ArrayRegexMaskGenerator",
        "replaceAllMatches": true,
        "pattern": "(.*)",
        "captureGroupMetadata": [
          {
            "generatorId": "ConstantGenerator",
            "constant": "test_value"
          }
        ]
      }
    }
  ]
}
```