---
title: "init(_:)"
framework: evaluations
role: symbol
role_heading: Initializer
path: "evaluations/evaluator/init(_:)"
---

# init(_:)

Creates an evaluator with the given evaluation closure.

## Declaration

```swift
init(_ evaluate: nonisolated(nonsending) @escaping (Input, ModelSubject<Input.ExpectedValue>) async throws -> Metric)
```

## Parameters

- `evaluate`: A closure that receives the input and subject, and returns a doc://com.apple.evaluations/documentation/Evaluations/Metric with a result value.