# EvaluatorsBuilder A result builder that enables declarative evaluator lists. ``` @resultBuilder struct EvaluatorsBuilder where Sample : SampleProtocol, Subject : EvaluationSubject ``` ## Overview Apply this builder to the `evaluators` property to remove the need for explicit array literals and type annotations: ```swift @EvaluatorsBuilder, ModelSubject> func buildEvaluators() -> [any EvaluatorProtocol, ModelSubject>] { Evaluator> { sample, subject in Metric("Match").scoring(1.0) } } ``` ## Topics ### Type Methods [`static func buildExpression(any EvaluatorProtocol) -> any EvaluatorProtocol`](/documentation/Evaluations/EvaluatorsBuilder/buildExpression(_:)) Wraps a single evaluator expression into the builder pipeline. [`static func buildOptional([any EvaluatorProtocol]?) -> [any EvaluatorProtocol]`](/documentation/Evaluations/EvaluatorsBuilder/buildOptional(_:)) Provides an empty array when an optional evaluator block is absent. [`static func buildPartialBlock(accumulated: [any EvaluatorProtocol], next: [any EvaluatorProtocol]) -> [any EvaluatorProtocol]`](/documentation/Evaluations/EvaluatorsBuilder/buildPartialBlock(accumulated:next:)-7lvjo) [`static func buildPartialBlock(accumulated: [any EvaluatorProtocol], next: any EvaluatorProtocol) -> [any EvaluatorProtocol]`](/documentation/Evaluations/EvaluatorsBuilder/buildPartialBlock(accumulated:next:)-88zf9) [`static func buildPartialBlock(first: [any EvaluatorProtocol]) -> [any EvaluatorProtocol]`](/documentation/Evaluations/EvaluatorsBuilder/buildPartialBlock(first:)-3o70b) [`static func buildPartialBlock(first: any EvaluatorProtocol) -> [any EvaluatorProtocol]`](/documentation/Evaluations/EvaluatorsBuilder/buildPartialBlock(first:)-875f9) --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)