# `Nous.Eval.Evaluators.Contains`
[🔗](https://github.com/nyo16/nous/blob/v0.17.1/lib/nous/eval/evaluators/contains.ex#L1)

Evaluator that checks if output contains expected substrings or patterns.

## Expected Format

The expected value can be:
- A list of strings: `["word1", "word2"]`
- A map with `:contains` key: `%{contains: ["word1", "word2"]}`
- A map with `:contains_any` key: `%{contains_any: ["word1", "word2"]}`
- A map with `:regex` key: `%{regex: ["pattern1", "pattern2"]}`

## Configuration

  * `:case_insensitive` - Ignore case (default: true)
  * `:match_all` - Require all items to match (default: true for :contains)

## Examples

    # Must contain all words
    TestCase.new(
      id: "contains_all",
      input: "What's the weather in Tokyo?",
      expected: %{contains: ["weather", "Tokyo"]},
      eval_type: :contains
    )

    # Must contain any word
    TestCase.new(
      id: "contains_any",
      input: "Say hello",
      expected: %{contains_any: ["hello", "hi", "hey"]},
      eval_type: :contains
    )

    # Regex patterns
    TestCase.new(
      id: "regex",
      input: "What is 25*4?",
      expected: %{regex: ["\\d+"]},
      eval_type: :contains
    )

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*Consult [api-reference.md](api-reference.md) for complete listing*