MLton 20210117

# MLtonPointer

    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.