Result-Builders-Basics-Full.swift

@resultBuilder
struct StringBuilder {
    
    static func buildBlock(_ components: String...) -> String {
        let filtered = components.filter { $0 != "" }
        return filtered.joined(separator: "⭐️")
    }
    
    static func buildOptional(_ component: String?) -> String {
        return component ?? ""
    }

    static func buildEither(first component: String) -> String {
        return component
    }

    static func buildEither(second component: String) -> String {
        return component
    }

    static func buildArray(_ components: [String]) -> String {
        return components.joined(separator: "")
    }

    static func buildExpression(_ expression: Int) -> String {
        return "\(expression)"
    }
    
    static func buildExpression(_ expression: String) -> String {
        return expression
    }

    static func buildFinalResult(_ component: String) -> Int {
        return component.count
    }

    static func buildFinalResult(_ component: String) -> String {
        return component
    }
}


@StringBuilder func greet(name: String, countdown: Int) -> String {

    for i in (0...countdown).reversed() {
        i
    }

    "Hello"

    if !name.isEmpty {
        "to"
        name
    } else {
        "World"
    }
}
print(greet(name: "Swift Senpai", countdown: 5))


@StringBuilder var greetCharCount: Int {
    "Hello"
    "World"
}
print(greetCharCount)