type
  TokenValue = union
    intValue: Int;
    stringValue: String
  end,
  Token = record
    kind: Int;
    value: TokenValue
  end,
  FILE = record
    dummy: Int
  end;

const
  SEEK_SET = 0, SEEK_CUR = 1, SEEK_END = 2;

--
-- External procedures.
--
proc fopen(pathname: String, mode: String): pointer to FILE; extern;
proc fclose(stream: pointer to FILE): Int; extern;
proc fseek(stream: pointer to FILE, off: Int, whence: Int): Int; extern;
proc ftell(stream: pointer to FILE): Int; extern;
proc fread(ptr: pointer to Char, size: Int, nmemb: Int, stream: pointer to FILE): Int; extern;
proc write(fd: Int, buf: pointer to Char, count: Int): Int; extern;

proc malloc(size: Int): pointer to Char; extern;
proc free(ptr: pointer to Char); extern;
proc calloc(nmemb: Int, size: Int): pointer to Char; extern;

proc memset(ptr: pointer to Char, c: Int, n: Int): pointer to Char; extern;

proc strlen(ptr: pointer to Char): Word; extern;

proc exit(code: Int); extern;

--
-- Standard procedures.
--
proc write_s(value: String);
begin
  write(0, value, strlen(value))
end;

proc write_b(value: Bool);
begin
  if value then
    write_s("true")
  else
    write_s("false")
  end
end;

proc write_c(value: Char);
begin
  write(0, @value, 1)
end;

proc write_i(value: Int);
var
  digit: Int, n: Int,
  buffer: array 10 of Char;
begin
  n := 9;
  buffer[9] := '0';

  while value /= 0 do
    digit := value % 10;
	value := value / 10;

	buffer[n] := Char(Int('0') + digit);
	n := n - 1
  end;
  while n < 10 do
    n := n + 1;
    write_c(buffer[n])
  end
end;

proc write_u(value: Word);
begin
  write_i(value)
end;

--
-- End of standard procedures.
--

proc test_record();
var r: Token;
begin
  write_s("\nTest record:\n");

  r.kind := 4;
  r.value.intValue := 8;

  write_i(r.value.intValue)
end;

proc test_primitive();
begin
  write_s("\nTest primitives:\n");
  write_u(25u);
  write_c('\n');

  write_i(8);
  write_c('\n');

  write_b(true);
  write_c('\n')
end;

proc read_source(filename: String): pointer to Char;
var
  input_file: pointer to FILE,
  source_size: Int,
  input: pointer to Char;
begin
  input_file := fopen(filename, "rb");

  fseek(input_file, 0, SEEK_END);
  source_size := ftell(input_file);
  fseek(input_file, 0, SEEK_SET);

  input := calloc(source_size + 1, 1);
  fread(input, source_size, 1, input_file);

  fclose(input_file);

  return input
end;

proc compile();
var
  input: pointer to Char,
  input_pointer: pointer to Char;
begin
  input := read_source("example.elna");

  input_pointer := input;
  while input_pointer^ /= '\0' do
    write(0, input_pointer, 1);
    input_pointer := input_pointer + 1
  end;

  free(input)
end;

begin
  compile();

  test_record();
  test_primitive();

  exit(0)
end.