import enso
import std/[os, strformat, sugar]

proc unsafe_void(str: string) =
  echo str

proc unsafe_int(str: string): int =
  echo str
  result = 1

func check_file(name: string): IO[string] =
  proc(): string =
    if fileExists(name):
      result = readFile(name)
    else:
      result = "Not found"

func main() =
  run strput("Hello from Enso!")

  let
    out_void: IO[void] = lift () => unsafe_void("void")
    out_int:  IO[int]  = lift () => unsafe_int("int")

  out_void()
  run strput(fmt"{out_int()}")

  let get_filename: IO[string] =
    proc(): string =
      let name: IO[string] = readstr(STDIN)
      echo "Enter the file name:"
      name()

  let
    nested: IO[IO[string]] = get_filename.map(check_file)
    joined: IO[string]     = nested.join

  run strput(joined())

  let flat: IO[string] = get_filename.flatmap(check_file)
  run strput(flat())

when isMainModule:
  main()