Yesod.Routes.TH.Types

The details of a ResourceParent gathered for a flattened resource: the parent's name, its path pieces, and the route attributes it contributes to its descendants.

The type arguments of a route datatype, paired with the source Name each was derived from. A monomorphic site like App has NoTyArgs; a parameterized one like MySub subsite has SomeTyArgs.

Carrying the (non-)emptiness in the type — rather than as a bare list with a separate null check — keeps "are there type args?" and "what are they?" a single fact, so the populated branch hands you the NonEmpty directly.

Build TyArgs from a list of (type, source-name) pairs.

The type arguments as a plain list (empty for NoTyArgs).

Just the Types of the arguments, in order.

Just the source Names of the arguments, in order.

How many type arguments there are.

Whether there are any type arguments (i.e. the site is parameterized).

Apply the type arguments to a head type (e.g. a route/subroute type constructor), left to right. This replaces the ad-hoc foldl' AppT con (fst <$> tyargs) that recurred across the generators.