MLton 20070826 MLtonStructure
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The MLton structure contains a lot of functionality that is not available in the Basis Library. As a warning, please keep in mind that the MLton structure and its substructures do change from release to release of MLton.
structure MLton:
   sig
      val eq: 'a * 'a -> bool
      val isMLton: bool
      val share: 'a -> unit
      val shareAll: unit -> unit
      val size: 'a -> int

      structure Array: MLTON_ARRAY
      structure BinIO: MLTON_BIN_IO
      structure CharArray: MLTON_MONO_ARRAY where type t = CharArray.array
                                            where type elem = CharArray.elem
      structure CharVector: MLTON_MONO_VECTOR where type t = CharVector.vector
                                              where type elem = CharVector.elem
      structure Cont: MLTON_CONT
      structure Exn: MLTON_EXN
      structure Finalizable: MLTON_FINALIZABLE
      structure GC: MLTON_GC
      structure IntInf: MLTON_INT_INF
      structure Itimer: MLTON_ITIMER
      structure LargeReal: MLTON_REAL where type t = LargeReal.real
      structure LargeWord: MLTON_WORD where type t = LargeWord.word
      structure Platform: MLTON_PLATFORM
      structure Pointer: MLTON_POINTER
      structure ProcEnv: MLTON_PROC_ENV
      structure Process: MLTON_PROCESS
      structure Profile: MLTON_PROFILE
      structure Random: MLTON_RANDOM
      structure Real: MLTON_REAL where type t = Real.real
      structure Real32: sig
                           include MLTON_REAL
                           val castFromWord: Word32.word -> t
                           val castToWord: t -> Word32.word
                        end where type t = Real32.real
      structure Real64: sig
                           include MLTON_REAL
                           val castFromWord: Word64.word -> t
                           val castToWord: t -> Word64.word
                        end where type t = Real64.real
      structure Rlimit: MLTON_RLIMIT
      structure Rusage: MLTON_RUSAGE
      structure Signal: MLTON_SIGNAL
      structure Socket: MLTON_SOCKET
      structure Syslog: MLTON_SYSLOG
      structure TextIO: MLTON_TEXT_IO
      structure Thread: MLTON_THREAD
      structure Vector: MLTON_VECTOR
      structure Weak: MLTON_WEAK
      structure Word: MLTON_WORD where type t = Word.word
      structure Word8: MLTON_WORD where type t = Word8.word
      structure Word16: MLTON_WORD where type t = Word16.word
      structure Word32: MLTON_WORD where type t = Word32.word
      structure Word64: MLTON_WORD where type t = Word64.word
      structure Word8Array: MLTON_MONO_ARRAY where type t = Word8Array.array
                                             where type elem = Word8Array.elem
      structure Word8Vector: MLTON_MONO_VECTOR where type t = Word8Vector.vector
                                               where type elem = Word8Vector.elem
      structure World: MLTON_WORLD
   end

Substructures

Values

Example of MLton.size

This example, size.sml, demonstrates the application of MLton.size to many different kinds of objects.

fun 'a printSize (name: string, min: int, value: 'a): unit=
   if MLton.size value >= min
      then
         (print "The size of "
          ; print name
          ; print " is >= "
          ; print (Int.toString min)
          ; print " bytes.\n")
   else ()

val l = [1, 2, 3, 4]

val _ =
   (
    printSize ("a char", 0, #"c")
    ; printSize ("an int list of length 4", 48, l)
    ; printSize ("a string of length 10", 24, "0123456789")
    ; printSize ("an int array of length 10", 52, Array.tabulate (10, fn _ => 0))
    ; printSize ("a double array of length 10",
                 92, Array.tabulate (10, fn _ => 0.0))
    ; printSize ("an array of length 10 of 2-ples of ints",
                 92, Array.tabulate (10, fn i => (i, i + 1)))
    ; printSize ("a useless function", 0, fn _ => 13)
    )

(* This is here so that the list is "useful".
 * If it were removed, then the optimizer (remove-unused-constructors)
 * would remove l entirely.
 *)
val _ = if 10 = foldl (op +) 0 l
           then ()
        else raise Fail "bug"
   
local
   open MLton.Cont
in
   val rc: int option t option ref = ref NONE
   val _ =
      case callcc (fn k: int option t => (rc := SOME k; throw (k, NONE))) of
         NONE => ()
       | SOME i => print (concat [Int.toString i, "\n"])
end

val _ =
   (print "The size of a continuation option ref is "
    ; if MLton.size rc > 1000
         then print "> 1000.\n"
      else print "< 1000.\n")

val _ =
   case !rc of
      NONE => ()
    | SOME k => (rc := NONE; MLton.Cont.throw (k, SOME 13))

Compile and run as usual.

% mlton size.sml
% ./size
The size of a char is >= 0 bytes.
The size of an int list of length 4 is >= 48 bytes.
The size of a string of length 10 is >= 24 bytes.
The size of an int array of length 10 is >= 52 bytes.
The size of a double array of length 10 is >= 92 bytes.
The size of an array of length 10 of 2-ples of ints is >= 92 bytes.
The size of a useless function is >= 0 bytes.
The size of a continuation option ref is > 1000.
13
The size of a continuation option ref is < 1000.


Last edited on 2007-08-23 03:45:32 by MatthewFluet.