In other languages, the builder pattern usually consists of just methods on a builder object that manipulate internal state until you 'build' an instance. Funct

In other languages, the builder pattern usually consists of just methods on a builder object that manipulate internal state until you 'build' an instance. Function builders on the other hand support building of a strong type. The builder can convert expressions into components that are then assembled into results. Some applications want to be able to represent the result as a strong generic type. As an example of this, imagine if let releaseName = releaseName { Div("Release \(releaseName)") else { Blink("Prerelease") } might be captured by such a builder as an Either<Div, Blink>.