I have two files, the **generic Server** in the library, and the **App**.
Server doesn't know the concrete type of the Session, it's only defined later
in the App.
How to write such code, the way I wrote it below doesn't work as for some
reason I can't modify global var object in the closure. ( _Error: 'sessions' is
of type <var Sessions[system.string]> which cannot be captured as it would
violate memory safety, declared here: play.nim(11, 28); using
'-d:nimNoLentIterators' helps in some cases_).
# server.nim ------------------------------------------
import std/[httpcore, asynchttpserver, asyncnet, tables, asyncdispatch]
type SessionData[S] = ref object
session: S
type Sessions[S] = Table[string, SessionData[S]]
proc build_http_handler[S](sessions: var Sessions[S]): auto =
return proc (req: Request): Future[void] {.async, gcsafe.} =
let session_id = "someid"
if session_id notin sessions: sessions[session_id] = SessionData[S]()
let session = sessions[session_id]
return req.respond(Http200, $(session.session))
proc run_server*[S] =
var sessions: Sessions[S]
var server = new_async_http_server()
async_check server.serve(Port(5000), build_http_handler(sessions),
"localhost")
run_forever()
# app.nim ------------------------------------------
run_server[string]()
Run
