@resultBuilder
struct HTMLBuilder {
static func buildBlock(_ components: String...) -> String {
components.joined(separator: "\n")
}
static func buildOptional(_ component: String?) -> String {
component ?? ""
}
static func buildEither(first component: String) -> String {
component
}
static func buildEither(second component: String) -> String {
component
}
}
func html(@HTMLBuilder content: () -> String) -> String {
"\n\(content())\n"
}
let page = html {
"Hello"
""
"Welcome
"
""
}