Allow URIs specified in file directives implicitly It seems to me that, by specifying that one wants to serve a given file at a specified URI, one is implying that this URI should be allowed.

con id = fold (fn nm => fn t :: Type => fn acc => [nm] ~ acc => [nm = t] ++ acc) []

con idT = id [D = int, E = float]

val idV = fn x : $idT => x.E