ParamsFromContext pulls the URL parameters from a request context, or returns nil if none are present.

MatchedRoutePathParam is the Param name under which the path of the matched route is stored, if Router.SaveMatchedRoutePath is set.

ParamsKey is the request context key under which URL params are stored.

Param is a single URL parameter, consisting of a key and a value.

Router is a http.Handler which can be used to dispatch requests to different handler functions via configurable routes.

Params is a Param-slice, as returned by the router.