Codegen.Gen
type 'a fn = 'a outerfn
type implementation = unit -> Interface.t
val implement : Interface.description -> implementation
val returning : 'a Idl.Param.t -> 'b Idl.Error.t -> ( 'a, 'b ) Result.t outerfn
val (@->) : 'a Idl.Param.t -> 'b outerfn -> ( 'a -> 'b ) outerfn