StrPair = tuple[k, v: string]

Context = object
  position*: int
  accept*: bool
  log*: ref string
  headers*: List[StrPair]

Handler = proc (req: ref Request; ctx: Context): Future[Context]

proc reject(ctx: Context): Context {.
raises: [], tags: []
.}

proc addPosition(ctx: Context; n: int): Context {.
raises: [], tags: []
.}

proc withPosition(ctx: Context; n: int): Context {.
raises: [], tags: []
.}

proc withLogging(ctx: Context; s: ref string): Context {.
raises: [], tags: []
.}

proc withHeaders(ctx: Context; hs: openArray[StrPair]): Context {.
raises: [], tags: []
.}

proc handle(h: Handler): auto {.
raises: [], tags: []
.}

proc `~`(h1, h2: Handler): Handler {.
raises: [], tags: []
.}

proc `->`(h1, h2: Handler): Handler {.
raises: [], tags: []
.}

proc serve(server: AsyncHttpServer; port: Port; handler: Handler; address = ""): Future[
    void] {.
raises: [FutureError], tags: [WriteIOEffect, ReadIOEffect, RootEffect]
.}

iterator items[A](list: List[A]): A

template `[]`(h1, h2: Handler): auto