macro proto name, [args]{
common
local count
  count = 0
  PROTO # name = 1

forward
  count = count + 1

  argPROTO # name # args = count

common
  countPROTO # name = count
}

proto MessageBox,\
    hWnd,\            ; handle of owner window
    lpText,\          ; address of text in message box
    lpCaption,\       ; address of title of message box
    uType             ; style of message box

macro adainv name, [args]
{
common
local count, passed
  count = 0

  if ~defined PROTO # name
    display "There is no procedure nor proto with name """, `name, """"
    err
  end if

forward
  if 1
  match arg ==> value, args
  \{
    if ~defined argPROTO \# name \# arg
      display \`arg, " is not an argument of ", \`name
      err
    end if

    if defined arg \# passed
      display "Argument ", \`arg, " of ", \`name, " already passed"
      err
    end if
    arg \# passed equ 1    ; To signal arg was passed

    count = count + 1
  else
  \}
    display "Invalid argument"
    err
  end if

common
local arg_list
arg_list equ

  if countPROTO # name > count
    display "At least an argument is missing"
    err
  end if

; ##### At this point we are ready to reorder the arguments (if needed) before calling the procedure/function

}

adainv MessageBox, hWnd => 0, lpText => text, lpCaption => NULL, uType => MB_ICONINFORMATION
adainv MessageBox, uType => MB_ICONINFORMATION, lpCaption => NULL, lpText => text, hWnd => 0
adainv MessageBox, lpCaption => NULL, hWnd => 0, lpText => text, uType => MB_ICONINFORMATION