swift-foundation/Sources/FoundationEssentials/Predicate/Expressions/Equality.swift

//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2022-2023 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//

@available(macOS 9999, iOS 9999, tvOS 9999, watchOS 9999, *)
extension PredicateExpressions {
    public struct Equal<
        LHS : PredicateExpression,
        RHS : PredicateExpression
    > : PredicateExpression
    where
        LHS.Output == RHS.Output,
        LHS.Output : Equatable
    {
        public typealias Output = Bool
        
        public let lhs: LHS
        public let rhs: RHS
        
        public init(lhs: LHS, rhs: RHS) {
            self.lhs = lhs
            self.rhs = rhs
        }
        
        public func evaluate(_ bindings: PredicateBindings) throws -> Bool {
            try lhs.evaluate(bindings) == rhs.evaluate(bindings)
        }
    }
    
    public static func build_Equal<LHS, RHS>(lhs: LHS, rhs: RHS) -> Equal<LHS, RHS> {
        Equal(lhs: lhs, rhs: rhs)
    }
}

@available(macOS 9999, iOS 9999, tvOS 9999, watchOS 9999, *)
extension PredicateExpressions.Equal : StandardPredicateExpression where LHS : StandardPredicateExpression, RHS : StandardPredicateExpression {}

@available(macOS 9999, iOS 9999, tvOS 9999, watchOS 9999, *)
extension PredicateExpressions.Equal : Codable where LHS : Codable, RHS : Codable {}

@available(macOS 9999, iOS 9999, tvOS 9999, watchOS 9999, *)
extension PredicateExpressions.Equal : Sendable where LHS : Sendable, RHS : Sendable {}