(system-include "carp_io.h")

(register-type FILE)

(defmodule IO
  (doc println "prints a string ref to stdout, appends a newline.")
  (register println (Fn [(Ref String)] ()))
  (doc print "prints a string ref to stdout, does not append a newline.")
  (register print (Fn [(Ref String)] ()))
  (doc get-line "gets a line from stdin.")
  (register get-line (Fn [] String))
  (doc get-char "gets a character from stdin.")
  (register get-char (Fn [] Char) "getchar")
  (doc read-file "returns the contents of a file passed as argument as a string.")
  (register read-file (Fn [&String] String))
  (doc exit "exit the current program with a return code.")
  (register exit (Fn [Int] a))
  (register EOF Char)
  (doc EOF "the End-Of-File character as a literal.")
  (doc fopen "opens a file by name using a mode (one or multiple of [r]ead, [w]rite, and [a]ppend), returns a file pointer.")
  (register fopen (Fn [&String &String] (Ptr FILE)))
  (doc fclose "closes a file pointer.")
  (register fclose (Fn [(Ptr FILE)] ()))
  (doc fgetc "gets a character from a file pointer.")
  (register fgetc (Fn [(Ptr FILE)] Char))
  (doc fwrite "writes to a file pointer.")
  (register fwrite (Fn [a Int Int (Ptr FILE)] ()) "fwrite")

  (doc read->EOF "reads a file given by name until the End-Of-File character is reached.")
  (defn read->EOF [filename]
    (let [f (IO.fopen filename "rb")
          c (Char.from-int 0)
          r []]
      (do
        (while (do (set! c (IO.fgetc f))
                   (/= c IO.EOF))
          (set! r (Array.push-back r c)))
        (IO.fclose f)
        (String.from-chars &r))))
)