gistfile1.txt

Error: This expression has type
         string Async.Std.Pipe.Reader.t option ->
         Async.Std.Socket.Address.Inet.t ->
         Cohttp_async.Request.t ->
         Cohttp_async.Server.response Async.Std.Deferred.t
       but an expression was expected of type
         body:string Async.Std.Pipe.Reader.t option ->
         Async.Std.Socket.Address.Inet.t ->
         Cohttp_async.Request.t ->
         Cohttp_async.Server.response Async.Std.Deferred.t

gistfile2.txt

open Core.Std
open Async.Std
open Async_extra
open Cohttp
open Cohttp_async


let where_to_listen =
  Tcp.Where_to_listen.create
    ~socket_type:Socket.Type.tcp
    ~address:(Socket.Address.Inet.create_bind_any ~port:4566)
    ~listening_on:(fun (`Inet (_, port)) -> port)

let server (body:string Pipe.Reader.t option) (address:Socket.Address.Inet.t) (req:Cohttp_async.Request.t)  = Server.respond_with_string ~headers:(Header.init ()) ~code:(`Code 200) "foo"

let () =
  Server.create ~max_connections:10 ~max_pending_connections:10 ~on_handler_error:`Raise
                where_to_listen server;
  never_returns (Scheduler.go ());