MLtonPointer

MLton

signature MLTON_POINTER =
   sig
      eqtype t

      val add: t * word -> t
      val compare: t * t -> order
      val diff: t * t -> word
      val getInt8: t * int -> Int8.int
      val getInt16: t * int -> Int16.int
      val getInt32: t * int -> Int32.int
      val getInt64: t * int -> Int64.int
      val getPointer: t * int -> t
      val getReal32: t * int -> Real32.real
      val getReal64: t * int -> Real64.real
      val getWord8: t * int -> Word8.word
      val getWord16: t * int -> Word16.word
      val getWord32: t * int -> Word32.word
      val getWord64: t * int -> Word64.word
      val null: t
      val setInt8: t * int * Int8.int -> unit
      val setInt16: t * int * Int16.int -> unit
      val setInt32: t * int * Int32.int -> unit
      val setInt64: t * int * Int64.int -> unit
      val setPointer: t * int * t -> unit
      val setReal32: t * int * Real32.real -> unit
      val setReal64: t * int * Real64.real -> unit
      val setWord8: t * int * Word8.word -> unit
      val setWord16: t * int * Word16.word -> unit
      val setWord32: t * int * Word32.word -> unit
      val setWord64: t * int * Word64.word -> unit
      val sizeofPointer: word
      val sub: t * word -> t
   end

eqtype t

the type of pointers, i.e. machine addresses.
add (p, w)

returns the pointer w bytes after than p. Does not check for overflow.
compare (p1, p2)

compares the pointer p1 to the pointer p2 (as addresses).
diff (p1, p2)

returns the number of bytes w such that add (p2, w) = p1. Does not check for overflow.
get<X> (p, i)

returns the object stored at index i of the array of X objects pointed to by p. For example, getWord32 (p, 7) returns the 32-bit word stored 28 bytes beyond p.
null

the null pointer, i.e. 0.
set<X> (p, i, v)

assigns v to the object stored at index i of the array of X objects pointed to by p. For example, setWord32 (p, 7, w) stores the 32-bit word w at the address 28 bytes beyond p.
sizeofPointer

size, in bytes, of a pointer.
sub (p, w)

returns the pointer w bytes before p. Does not check for overflow.