Celestin Apprentice 4/Apprentice-Release4.iso/Source Code/C/Applications/SML⁄NJ 93+/Documentation/bugs/NEWS

Text File | 1995-12-30 | 129.2 KB | 3,628 lines | [TEXT/R*ch]

-------------------------------------------------------------------------
Standard ML of New Jersey, Version 0.93, February 1, 1992

This release is mostly bug fixes. Considerable effort has been put
into making the HPPA more robust.

Bug fixes:

489. exportFn image size too large
593. Compiler bug from bad overload declaration
671. visibility of parameter in functor signature
673. failure of type propagation with higher-order functors
674. System.Env.filterEnv raises exception IntmapF
676. Out of order record field evaluation.
677. memory leak
679. "Compiler bug: addObject" while compiling the Edinburgh library
680. Bad vertical alignment prettyprinting case expression.
681. building on SGI Indigos with cc version 3.10
682. excess newlines in compiler warning message
683. Compiler bug: Extern: update_structure 2
684. Compiler bug: checkList
685. loss of line numbers loading with System.Compile
686. floating-point divide by zero is broken on SGI
687. src/Makefile is out of date.
688. profiler doesn't compile
689. Compiling lambda prolog fails with compiler bug "adjust_variable".
690. maskSignals breaks interactive input
691. Compiler bug: ModuleUtil: lookFormalBinding 1
692. signal handling on 386 can dump core
694. System.Compile.execute provokes compiler bug ModuleComp.getImport
695. segmentation fault involving System.Ast
696. Type system error in "includes" of signatures
697. wrong Subscript exception in ByteArray
699. "Compiler bug: ModuleUtil: lookFormalBinding 1" (secondary)
700. wrong printing with toplevel vector pattern
701. wrong types printed for top-level exception declarations
703. betaexpand in cpsopt goes into infinite loop
704. System.Unsafe.SysIO.access raises exception instead of returning false
707. overloading in the profiler
708. array too large

-------------------------------------------------------------------------
Standard ML of New Jersey, Version 0.92, November 18, 1992

This is a prerelease version that is being made available for testing
in preparation for the next public release, which is expected to
be 0.93.  The public release should follow in about a month, depending
on the extent of problems discovered with this version.  This is still
a development version, but we think it is fairly solid.  The known
bugs are listed in the openbugs and masterbugs files available in
the ftp "working" directory at research.att.com.

Ports:

*  IBM RS6000 workstations under AIX by Lal George.  Use makeml option
   "-rs6000 aix".

*  AUX 3.0 on the Macintosh II family thanks to Thomas Eberhardt
   ([e-mail]).  Use makeml option "-m68 aux".

*  Mark Leone has improved Guttesen's I386 port and has provided support
   for BSD/386, and Mach operating systems.  Use makeml options
   "-i386 bsd", "i386 -bsd386", or "i386 mach".

*  Andrew Tolmach has provided runtime support for the Sequent Symmetry
   running under the Dynix 3 operating system.  Work is continuing on
   support for the MP interface and for the Dynix/PTX operating system.
   Use option "-sequent dynix3" with makeml.

We hope to have a working port for HP-PA systems by 0.93.


New Features:

======================================================================
* No more infixes in signatures
======================================================================

Infix directives in signatures are no longer recognized. This allows
the parser to be more independent from the elaboration. The only thing
it needs is an environment containing the top-level fixity bindings.
The spurious TAB binding used to represent fixity information has
disappeared.  The parser issues no complaints except when it detects a
syntax error.

If you took advantage of this unofficial feature, redefine the infix
properties after each open of the structures concerned.


======================================================================
* Syntax trees
======================================================================

"Unelaborated" syntax trees are provided in the structure System.Ast.
These can be produced from source text using System.Compile.parse and
can be compiled using System.Compile.compileAst.


======================================================================
* Better Match and bind exception messages (Pierre Cregut)
======================================================================

If the file containing the definition of the binding or the match that has
caused the exception has been compiled with line numbers, then the reference
System.errorMatch will contain a string giving the position of the failure
at Runtime.  This information is automatically displayed at toplevel if the
program aborts with an uncaught Match or Bind exception.


======================================================================
* Vector expressions and patterns
======================================================================

The notation #[e1,...,en] denotes a vector value.  Similarly
#[p1,...,pn] is a vector pattern with element patterns p1 through pn.


======================================================================
* First-class environments
======================================================================

System.Env: ENVIRONMENT provides access to the environments used by
the compiler.  See doc/compile.doc.


======================================================================
* Compilation interface
======================================================================

System.Compile: COMPILE provides access to basic compilation functions.
See doc/compile.doc.


======================================================================
* Printing cyclic values
======================================================================

It is now possible to print values containing cycles because of the use
of references or arrays.

The object beginning the loop is printed as

  <object> as %<number>

and occurrences inside its definition are printed as %<number>.

This feature can be turned off by setting the flag System.Print.printLoop
(: bool ref) to false.


======================================================================
* Printing arrays
======================================================================

The contents of arrays are now printed.  Delimiters are [| and |] (the
contents of vectors were already printed).  The array delimiters don't
work for input.


======================================================================
* Print control
======================================================================

System.Print : PRINTCONTROL replaces System.Control.Print (which is
temporarily retained and defined to be equal to System.Print).
The definition of PRINTCONTROL is

  signature PRINTCONTROL =
  sig
    type outstream
    val printDepth : int ref
    val printLength : int ref
    val stringDepth : int ref
    val printLoop : bool ref
    val signatures : int ref
    val pathnames : int ref
    val out : outstream ref
    val linewidth : int ref
    val say : string -> unit
    val flush: unit -> unit
  end

Almost all printing by the SML system (except for some diagnostic printing
that is normally disabled) uses System.Print.say.  The destination for
printing can be changed by redefining System.Print.out.  For instance,

  System.Print.out := open_out "/dev/null";

will suppress printing.  System.Print.flush flushes output to the
stream in System.Print.out.


======================================================================*
* Pretty Printing  (Konrad Slind)
======================================================================

There is a new facility for installing user-defined prettyprinters
over (monomorphic) user-defined types for use by the top-level loop of
the SML compiler.  The user can also directly use the prettyprinting
functions provided in System.PrettyPrint.  See doc/prettyprint.doc
for details.


======================================================================
* Higher-order modules (Pierre Cregut)
======================================================================

As an experimental extension of the module system, functors may now be
defined in structures and functor signatures may be defined and
referred to in structure signatures.  See doc/modules.doc.


======================================================================
* Info  (Pierre Cregut)
======================================================================

A utility in tools/info is now available for displaying information on
bindings.  The file tools/info/info.sml contains the definition of a
structure Info that provides two basic functions:

- info: string list -> unit
Takes the full path of an object and search informations on that
object (same kind as what is displayed when the object was defined).

- search: string -> unit
Takes a string and looks for all visible bindings containing
that string as a substring.  It walks through the full environment
tree (i.e. top-level environment, top-level structures, their
substructures, etc.).

Example:

- Info.info ["+"];
val + : 'a * 'a -> 'a as + : int * int -> int + : real * real -> real

infix 6 +

val it = () : unit
- Info.info ["Array"];
structure Array :
  sig
    eqtype 'a array
    exception Size
    exception Subscript
    val array : int * '1a -> '1a array
    val arrayoflist : '1a list -> '1a array
    val length : 'a array -> int
    val sub : 'a array * int -> 'a
    val tabulate : int * (int -> '1a) -> '1a array
    val update : 'a array * int * 'a -> unit
  end

val it = () : unit
- Info.search "compile";
variable or constructor NewJersey.System.Compile.compile
variable or constructor NewJersey.System.Compile.compileAst
variable or constructor System.Compile.compile
variable or constructor System.Compile.compileAst
val it = () : unit


======================================================================
* makeml man page
======================================================================

A revised man page for makeml is provided in the doc directory.


======================================================================


Performance
===========

Space usage for compilation and user programs is significantly lower.
Speed of generated code is somewhat slower, partly as a consequence of
fixing some space safety problems.


Looking Ahead
=============

After 0.93 the next big change is that the batch compiler will
disappear and the SourceGroup separate compilation system will be used
to compile the compiler.  A single type secure linkage mechanism will
be used by the interactive top-level, separate compilation, and
bootstrapping.  The System.Compile interface will change substantially.

"Or" patterns will be supported (e.g. "fn ((nil,x) | (x,nil)) => x").



Bugs fixed since 0.91
=====================
(see masterbugs for descriptions)

657. vector values not prettyprinted
661. prettyprinter -- Compiler bug: PPTable.install_pp
663. gc loop on illegal character
664. installing on Sony RISC NEWS (? not checked)
665. Compiler bug: getSymbols on opening nonexistent structures.
667. Compiler bug: getvars(STRdec)/fn opening a structure
668. missing info in syntax error messages
669. redundant rule added in some matches
670. missing indicators in redundant match warning messages
672. start() in i386 Mach
-------------------------------------------------------------------------
Standard ML of New Jersey, Version 0.91, October 26, 1992
Added to this version are:

- The runtime has been ported to AUX 3.0

- New monomorphic weak pointer abstraction (see perv.sig and perv.sml)

======================================================================
Higher Order Functors
---------------------
A new "curried" notation for functor is available:

  functor f <par1>....<parn> = <structure def>

where <pari> is as usual :
  (<id>:<signature>)
or
  (<signature body>)
A corresponding functor signature can be defined by:
  funsig f <par1> ... <parn> = <signature def>

functor application is also available:

  f (<arg1>) ... (<argn>)

with <argi> as usual (structure def or structure body).

The abstract syntax has been a little cleaned up to accomodate those
new changes.

strexp = ...
       | AppStr of path * (strexp * bool) list (* application *)

The boolean just states if the structure or just its body was given

fctexp = ...
       | FctFct of  {                     (* definition of a functor *)
             params     : (symbol option * sigexp) list,
             body       : strexp,
             constraint : sigexp option}

fsigexp = ...
        | FsigFsig of {param: (symbol option * sigexp) list, def:sigexp}
                                                  (* defined funsig *)

The symbol option contains the name of the parameter if it was named.

======================================================================
Parser
------
Infix notations in signatures are no more recognised. This allows the
parser to be more independant from the elaboration. The only thing it
needs is an environment containing the top-level fixity bindings.  The
spurious TAB binding used to represent fixity information has
disappeared.  The parser issues no more complaints except if it
detects a syntax error.

If you took advantage of this unofficial feature, redefine the infix properties
after each open of the structures concerned.

======================================================================
Printing
--------
It is now possible to print objects containing loops because of the use
of references or arrays.

The object begining the loop is printed as
<object> as %<number>
and its occurence inside its definition are printed as %<number>.

This feature can be turned off by togling the flag
System.Control.Print.printLoop (bool ref) to false.

The contents of arrays are now printed.  Delimiters are [| and |] (the
contents of vectors were already printed).

======================================================================
Match and bind exception
------------------------
If the file containing the definition of the binding or the match that has
caused the exception has been compiled with line numbers, then the reference
System.errorMatch will contain a string giving the position of the failure
at Runtime. This information is automatically displayed at toplevel if the
program aborts with an uncaught Match or Bind exception.

======================================================================
Info
----
A utility in tools/info is now available for displaying information on
bindings.  The file tools/info/info.sml contains the definition of a
structure Info that provides two basic functions:

- info: takes the full path of an object and search informations on that
object (same kind as what is displayed when the object was defined).

- search: takes a string and looks for all visible bindings containing that
string as a subpart. It walks through the full tree.

Example:

- Info.info ["+"];
val + : 'a * 'a -> 'a as + : int * int -> int + : real * real -> real

infix 6 +

val it = () : unit
- Info.info ["Array"];
structure Array :
  sig
    eqtype 'a array
    exception Size
    exception Subscript
    val array : int * '1a -> '1a array
    val arrayoflist : '1a list -> '1a array
    val length : 'a array -> int
    val sub : 'a array * int -> 'a
    val tabulate : int * (int -> '1a) -> '1a array
    val update : 'a array * int * 'a -> unit
  end

val it = () : unit
- Info.search "compile";
variable or constructor NewJersey.System.Compile.compile
variable or constructor NewJersey.System.Compile.compileAst
variable or constructor System.Compile.compile
variable or constructor System.Compile.compileAst
val it = () : unit

                        -- cregut
======================================================================

Pretty Printing

There is a new facility for installing user-defined prettyprinters
over (monomorphic) user-defined types for use by the top-level loop of
the SML compiler. The underlying algorithm is that of Oppen (1980).
There are more expressive prettyprinting languages around, notably
that of PPML, but the Oppen interface has the benefit of being
efficiently implementable---it runs in constant space. Thus it is a
good option for modest prettyprinting tasks that need to be quick,
such as the printing of SML values.

The high-level view is that the user will define a prettyprinter for a
datatype and install it in a prettyprinter table.  When it comes time for
the compiler to print a value, it looks first in the prettyprinter
table, to see if a prettyprinter is installed for that type.  If so, it
calls the prettyprinter on the value, otherwise, it calls the default
printing routine.

The Oppen algorithm provides a {\em block} abstraction:  a block
establishes a level of indentation. Since blocks can be nested and
offset from one another, levels of indentation can be achieved.  A block
can be broken up by one or more {\em breaks}, which mark possible places
to add carriage returns. There are two styles of block: CONSISTENT
and INCONSISTENT.  If a consistent block does not fit completely
onto the current line, a carriage return will be added after each
component of the block.  If an INCONSISTENT block does not fit completely
onto the current line, a carriage return is added after the last
item that does fit on the line; this style of block conserves on
vertical space.


The Signature
-------------

The pervasive structure System.PrettyPrint has the following signature:

signature PRETTYPRINT =
sig
  datatype break_style = CONSISTENT | INCONSISTENT
  val begin_block : break_style -> int -> unit
  val end_block : unit -> unit
  val add_break : (int*int) -> unit
  val add_string : string -> unit
  val add_newline : unit -> unit
  val reset_pp : unit -> unit
  val flush_output : unit -> unit
  val set_line_width : int -> unit
  val set_pp_output_function : (string -> unit) -> (string -> unit)
  val install_pp : string list -> ('1a -> unit) -> unit
  val pp : (string -> unit) -> ('a -> unit) -> 'a -> unit
  val pp_to_string : ('a -> unit) -> 'a -> string
end

datatype break_style = CONSISTENT | INCONSISTENT

  This defines the type of breaks.

val install_pp (path: string list) (ppfn: 'a -> unit) : unit  (* unsafe! *)

  The first argument is a path designating a nullary type constructor in
  the current interactive top-level environment.  This must be
  generative, i.e. it must be a datatype or abstype constructor.  The
  second argument is a prettyprinting function for that type.  Note that
  this connection between the type constructor designated by the path
  and the printing function cannot be enforced by type checking, so this
  operation is unsafe.

  The function ppfn is installed in the interactive system's
  prettyprinter table and it will be used when printing values of
  the designated type.

  The facility will be extended to allow nonnullary type constructors
  in the future.

val pp (consumer: string -> unit) (ppfn: 'a -> unit) (v: 'a) : unit

  This takes a value v and a prettyprinter function ppfn for the type of
  v and applies the prettyprinter to the value, with the result directed
  to the consumer function.  This is useful when one wants to prettyprint
  values as a computation progresses, rather than just at the end.

val begin_block : break_style -> int -> unit

  This begins a new level of indentation, at the current offset from the
  left margin. The first argument determines how the block is to be
  broken. The second argument determines the new offset if the block
  gets broken.

val end_block ()

  Prettyprinting reverts to the previous level of indentation.

val add_break (size:int, offset:int): unit

  Notify the prettyprinting engine that a carriage return is possible.
  The argument to this function is a pair; the first member is the
  size of the break, the second member is an offset. This
  ``break'' offset is used for finer control over indentation than that
  offered by the block offset. The current block style and the size of
  the block determine what action is to be taken:

    * block_style = CONSISTENT and the entire block fits on the
    remainder of the current line: output size spaces.

    * block_style = CONSISTENT and the block does not fit on the rest
    of the line:  add a carriage return after each component in the block
    and add the block offset to the current indentation level.  Each
    component will be further indented by offset spaces.

    * block_style = INCONSISTENT and the next component of the
    current block fits on the rest of the line: Output size spaces.

    * block_style = INCONSISTENT and the next component doesn't
    fit on the rest of the line:  output a carriage return and indent to
    the current indentation level plus the block offset plus offset
    extra spaces.

  size is taken into account when determining if there is enough room
  to print the next component in the block.

val add_string (s: string) : unit

  Outputs the given string.

val add_newline () : unit

  Forces the output of a carriage return.

val set_line_width (line_width: int) : unit

  Allows the user to change the prettyprinting engine's notion of how
  wide the line is. This call re-allocates the token buffer used by the
  prettyprinting engine, and so should only be called when
  prettyprinting is not happening. The initial line width is 70
  characters.

val set_pp_output_function :(string -> unit) -> (string -> unit)

  Prettyprinting eventually boils down to the output of strings;
  blocks and breaks are just instructions for artfully arranging the
  strings. This function allows one to change the output function that
  gets applied to strings. The returned value is the current output
  function. The initial output function is

      fn s => output(std_out,s).


Example
-------

open System.PrettyPrint;

datatype Num = Zero | Suc of Num;

fun pp_Num Zero = add_string "Z"
  | pp_Num (Suc n) = ( pp_Num n; add_string "'" );

val _ = install_pp ["Num"] pp_Num;

datatype Nexp
  = Atom of Num
  | Add of (Nexp*Nexp);

fun pp_Nexp ne =
    let fun pr (Atom a) = pp_Num a
          | pr (Add(a1,a2)) =
          (pr a1;
               add_string " +";
               add_break(1,0);
               pr a2)
     in begin_block CONSISTENT 0;
        pr ne;
        end_block()
    end;

val _ = install_pp ["Nexp"] pp_Nexp;

- val A = Add (Atom(Suc(Suc(Suc(Suc(Suc(Suc(Zero))))))),
               Atom(Suc(Suc(Suc(Suc(Suc(Suc(Zero))))))));

val A = Z'''''' + Z'''''' : Nexp
- set_line_width 20;
val it = () : unit
- A;
val it =
  Z'''''' + Z''''''
  : Nexp
- set_line_width 10;

- A;
val it =
  Z'''''' +
  Z''''''
  : Nexp
- Add(A,A);
val it =
  Z'''''' +
  Z'''''' +
  Z'''''' +
  Z''''''
  : Nexp
-

======================================================================

Bug Fixes:
449. poor error message for mismatching datatype spec
469. infix precedence bound
473. inadequate error message
480. Exit status of makeml is 1.
489. exportFn image size too large
495. inaccurate emacs info file
501. out of date yacc example code
505. bad datatype definition accepted
507. most negative integer causes compiler bug (see also 630, 632)
511. dying on interupt with SIGEMT (same as 484, 518)
513. not waiting for execute children
517. type errors in examples/cat.sml
532. squaring big real number dumps core on sparc (see also 638)
536. twig out of date
541. warnings while compiling runtime
544. poor error message
549. Match exception while compiling
552. Error message line numbers from std_in (see also 575)
553. incorrect syntax accepted (not a bug)
554. unused token constructor QUERY
566. An addition to sun2hp.el
582. interaction of open declarations and eval_stream
602. uncaught exception UnboundTable using System.Env.describe
608. minor error in runtime
609. include syntax
610. changeLvars broken
613. Compiler bug message on occurence of typevar in signature
616. overloading versus user-bound type variable
617. interpreter fails with "no default in interp"
622. Bus error on DECstation 5000/200
623. wildcard is equivalent to a serie of wildcards (see also 629)
624. System.Env.filterEnv causes Compiler bug: copystat.
625. Runbind exception still being raised.
633. space leak
635. byteArray.update and ByteArray.sub raise Ord
636. Vector patterns don't work at top level
638. subnormal numbers
640. flakiness of System.Env (particularly filterEnv)
642. Sourcegroup 2.1 dependency analysis fails (see also bug 649)
643. building smld produces Compiler bug: DebugError: ...
645. Compiler bug from bugs 183,228,343 code: CoreInfo.coreLty3
646. module test tile mod14.sml fails with Compiler bug: ModuleUtil: getFctStamp
647. PWR_2_CALLEESAVE not defined in some cases
649. too strong optimization of datatype constructor (same as 642)
650. Real.realfloor has wrong type
651. System.Directory.cd fails on numbers as directory names
652. Compiler bug: contmap enterv 123 building HOL
653. VECTOR signature isn't pervasive (unlike ARRAY)
654. System.Directory.cd fails on valid pathnames (same as 651)
655. Compiling Isabelle-92 generates a bus error
656. Excessive dead code
657. vector values not prettyprinted
658. Compiler bug: PrintVal.switch: none of the datacons matched

xxx uncaught exception SpillFreemap in closure profiling
-------------------------------------------------------------------------
Standard ML of New Jersey, Version 0.90 September 22, 1992


60 files changed and 16 new files were added to this version.

---Bug Fixes---
Appel:

469    infix precedence bound
507     most negative integer causes compiler bug (see also 630, 632)
532      squaring big real number dumps core on sparc (see also 638)
541     warnings while compiling runtime
554     unused token constructor QUERY
566      An addition to sun2hp.el (?)
609     include syntax
617     interpreter fails with "no default in interp"
638    subnormal numbers

Jhr:

633    space leak bug
636      top-level vector pattern bug
635    inline bytearray ops bug

Cregut:
623     wildcard is equivalent to a series of wildcards (see also 629)
646    test file mod14.sml fails with Compiler bug: ModuleUtil: getFctStamp
642    Sourcegroup 2.1 dependency analysis fails

---Changes---
Jhr:

    Made Real.abs an inline operation

Zhong:

          The new cps/convert.sml now generates multi-argument cps escaping
          functions and propagates the appropriate type information into the
          back end if the System.Control.CG.representation tag is turned on.
          The new cpsopt and closure modules dealing with multi-argument
          escaping user and continuation functions are expected soon.

Leone:
    Rewrote Guttesen's Windows i386 code generator resulting
    in a 20% reduction in code size and 25% improvement in running
    speeds (at least on the SX chip). Ported the runtime to Mach
    and BSD/386.

Lal:
    Removed the branch delayed architecture assumption from the
    scheduler. Scheduling is now driven by latencies associated
    with each instruction. (This change will affect anyone writing
    a code generator.)

    Implemented the RS6000 code generator. Some preliminary numbers:

    All times in seconds.
    --------------------------------------------------------------------
           IBM RS6000 (v0.88) | SPARC (v0.86)     | RATIO sparc/rs6k
    ==============================|===================|==================
    Program:   compile  execute   | compile  execute  | compile  execute
    ------------------------------|-------------------|------------------
    boyer          19.97     2.51    |  31.32    3.80    |   1.57     1.51
    life         5.51    22.39    |   7.90   22.13    |   1.43     0.99
    k-bendix    14.59    16.39    |  24.69   25.67    |   1.69     1.57
    simple      37.95    54.62    |  89.35   72.28    |   2.35     1.32
    mandelbrot   0.90    23.88    |   0.90   30.24    |   1.00     1.26
    lexgen      28.68    17.8     |  50.64   19.27    |   1.77     1.08
    vliw       107.34    31.44    | 171.39   40.96    |   1.60     1.30
    yacc       134.10     5.63    | 252.56    8.05    |   1.88     1.42
    cml-sieve   24.09    25.75    |  38.92   39.60    |   1.61     1.54

---Changed Files---
all
makeml
basics/access.sml
basics/primop.sig
boot/makemos.sml
boot/math.sml
boot/perv.sml
build/index.sml
build/linkage.sml
codegen/interp.sml
coder/coder.sml
coder/machinstr.sig
cps/cmachine.sig
cps/convert.sml
cps/cps.sml
cps/cpscomp.sml
cps/cpsopt.sml
cps/expand.sml
cps/generic.sml
cps/limit.sml
elaborate/elabcore.sml
env/environ.sml
env/prim.sml
m68/m68.sml
m68/m68ascode.sml
m68/m68coder.sig
m68/m68mcode.sml
mips/mips.sml
mips/mipsas.sml
mips/mipsdepend.sml
mips/mipsinstr.sml
mips/mipsmc.sml
modules/applyfct.sml
parse/astutil.sig
parse/astutil.sml
parse/ml.grm
parse/ml.grm.sig
parse/ml.grm.sml
print/printdec.sml
runtime/MIPS.prim.s
runtime/Makefile
runtime/allmo.c
runtime/cfuns.c
runtime/cstruct.c
runtime/exncode.c
runtime/export.c
runtime/fpregs.h
runtime/linkdata.c
runtime/ml_os.h
runtime/ml_state.h
runtime/run_ml.c
runtime/signal.c
runtime/sun2hp.el
sparc/sparc.sml
sparc/sparcas.sml
sparc/sparcinstr.sml
sparc/sparcmc.sml
translate/inlineops.sml
translate/tempexn.sml
vax/vax.sml


---New Files---
rs6000/rs6000.sml
rs6000/rs6000as.sml
rs6000/rs6000depend.sml
rs6000/rs6000glue.sml
rs6000/rs6000instrset.sml
rs6000/rs6000mc.sml

i386/i386.sml
i386/i386ascode.sml
i386/i386coder.sig
i386/i386glue.sml
i386/i386jumps.sig
i386/i386jumps.sml
i386/i386mcode.sml

runtime/RS6000.prim.s
runtime/I386.prim.s
runtime/export-rs6000-aix

-------------------------------------------------------------------------
Standard ML of New Jersey, Version 0.89, September 4, 1992

63 files were changed and 2 new ones added in this version 89.
1 file (translate/mcopt.sml) is deleted from 88.

Main Changes:

1) The intermediate lambda language (basics/lambda.sml) is modified to
   carry type information from the front end to the back end for the
   purpose of implementing representation analysis. This includes
   corresponding changes of abstract syntax, type checker, match compiler,
   linking interfaces between different modules, thinning interfaces, the
   translate module, and the convert module. The new flag System.Control.
   CG.representations which activates representation analysis is currently
   turned off in this version. All type information are temporarily thrown
   away after the convert phase.

2) A much cleaner and faster closure module closure.sml. The calleesaves
   and non-calleesavees are merged more elegantly; calleesaves 1 works
   now; in compiling the compiler, the new closure modules is about 44%
   faster than the old one in version 88.

3) Fixes the following bug:

     461. overloading and weak polymorphism
     539. weak typing bug
     607. weak typing
     612. bad lambda depth calculated in type checker
     614. high-order-functor thinning-in
     618. LOOKUP FAILS, Compiler bug: 110 in CPSgen
     619. Compiler bug: Escapemap on xxxx
     620. higher-order functor causes Compiler bug
     621. polymorphic equality not eliminated as often as it should be
     624. System.Env.filterEnv causes Compiler bug: copystat.
     626. extra spaces in SPARC.prim.s

--------------------------------------------------------------------------
cps/closure.sml:
cps/contmap.sml
    A much cleaner version (than 87) by Trevor: the calleesaves and
    non-calleesavees are merged more elegantly; calleesaves 1 works
    now; the closure phase is about 30% faster than 86.
    Zhong merges the ebtest function in closure.sml into contmap.sml.
    This results in another 18% speedup for the closure phase.
    Zhong fixed the single element closure problem and also the
    fillin bug.

--------------------------------------------------------------------------
Mark's Changes:

modules/applyfct.sml
modules/abstractfct.sml
elaborate/elabstr.sml
basics/typesutil.sig
basics/typesutil.sml
runtime/SPARC.prim.s
typing/typecheck.sml

     Fixes the following bug:
        461. overloading and weak polymorphism
        539. weak typing bug
        607. weak typing
        612. bad lambda depth calculated in type checker
        622. extra spaces in SPARC.prim.s

--------------------------------------------------------------------------
Pierre's Changes:

elaborate/elabstr.sml:
       same as Mark's changes. Fixes an old bug of type-checking.
       The local declarations in a top-level local were considered
       as top level.

modules/applyfct.sml:

     The thinning computed in the thinning of the argument = pair
     parameter-parent. But what we want is the thinning of the
     parameter only. This code extracts it.

modules/instantiate.sml:

     Except the pleasure of fixing a partial match, these changes provide
     a fix to a bug in functor signature instantiation. To instantiate the
     body, you need to give to elabstr a predicate identifying stamps
     belonging to the argument in the template body. The function provided
     so far was wrong because it didn't distinguished global stamps from
     local ones: e.g.,
                 funsig f() = struct val x:int end
     couldn't be instantiated correctly because it believed that int was
     declared in the argument of f. Having the right function is a little
     complex because the argument is the parameter + .... the parent, which
     is the body of the embedding functor and its argument and so on.

env/environ.sml:

     Getbindings was completely wrong. In fact the old version relied on
     the assumption that there was a binding per symbol, so when you
     used it you could merge the list of symbols and the list of bindings
     This is no more true, (we can have 0 (nothing found but no error
     raised in the filtering) 1 old case or 2 (an object and its fixity
     info)) So we keep the symbols with it. In fact fixity info are kept
     in a separate list.

boot/system.sig
boot/perv.sml
parse/ast.sml
./all

     fixes the "exporting the AST" bug. see comments in ast.sml.

--------------------------------------------------------------------------
Zhong's Changes:

./all
     Add transtypes.sml and transbinding.sml. And change the compilation
     order of several files because of the new dependencies.

absyn/absyn.sml
     Change the definition of the abstract syntax, more specifically
      (1) VARexp of var ref * ty option
            if "var" has polymorphic type, "ty option" specifies its
            corresponding type instance at this place; if "var" has
            monomorphic type, "ty option" is NONE.

      (2) CONexp of datacon * ty option
          CONpat of datacon * ty option
          APPpat of datacon * ty option * pat
            if "datacon" has polymorphic type, "ty option" specifies
            its corresponding type instance at this place; if "datacon"
            has monomorphic type, "ty option" is NONE.

      (3) FNexp of rule list * ty
            "ty" specifies the argument type of this function.

      (4) RAISEexp of exp * ty
            "ty" specifies the result type of this RAISEexp.

      (5) VECTORpat of pat list * ty
            "ty" specifies the type of the contents in the vector.


       Files affected by this:
         absyn/printabsyn.sml
         build/index.sml
         build/linkage.sml
         build/prof.sml
         debug/debugger.sml
         debug/dprintabsyn.sml
         debug/instrum.sml
         debug/queries.sml
         debug/static.sml
         debug/util.sml
         elaborate/elabcore.sml
         elaborate/elabutil.sml
         elaborate/misc.sml
         print/printdec.sml
         translate/mc.sml
         translate/mccommon.sml
         translate/nonrec.sml
         translate/tempexpn.sml
         translate/translate.sml
         typing/typecheck.sml

basic/lambda.sml
     The new intermediate lambda language. More specifically,
      (1) Add a notion of lambda type --- the new datatype lty.
          The translation from ML types to Lambda.lty is defined
          in translate/transtypes.sml and translate/transbinding.sml.
          (for more doc, see basics/lambda.sml itself)

      (2) Remove the record tag from the lambda language, add a new
          constructor called VECTOR. This still distinguishes VECTOR
          and RECORD in translate phase. The lambda types for VECTOR
          and RECORD are different, one is BOXEDty while another is
          RECORDty.

      (3) Add new constructors WRAP and UNWRAP.

      (4) Add lty information into the dataconstr type

      (5) In FN(v,t,_), t is the type of v; in FIX(fl,tyl,_,_), tyl
          is a list of types for fl; in RAISE(e,t), t is the result
          type of the expression RAISE(e,t); in PRIM(p,t), t is the
          type of the primitive p.

      (6) BOGUSty is a place holder.

      Files affected by this:
        build/compile.sml
        build/computil.sml
        build/evalloop.sml
        build/process.sml
        codegen/interp.sml
        codegen/lambdaopt.sml
        codegen/opt.sml
        codegen/reopen.sml
        cps/convert.sml
        translate/equal.sml
        translate/inlineops.sig
        translate/inlineops.sml
        translate/mc.sml
        translate/mccommon.sml
        translate/mcprint.sml
        translate/reorder.sml
        translate/translate.sml
        translate/unboxed.sml

basics/typesutil.sig
basics/typesutil.sml
     Add a function getRecTyvarMap : int * Types.ty -> (int -> bool);
     This function check whether a bound tyvar has occurred in some
     datatypes whose type constructor has an non-zero arity, e.g.,
     'a list. This is useful for representation analysis.

boot/perv.sig
boot/perv.sml
build/batch.sml
     Add a new flag System.Control.CG.representations used to turn on
     or off all representation analysis code.

build/batch.sml
build/boot.sml
build/compile.sml
build/computil.sml
build/evalloop.sml
build/process.sml
     Add the inverseEnv to be part of the arguments in the function
     "process". InverseEnv is useful for finding out the type of an
     arbitrary lvar. Add a new function called gengetty in the
     computil.sml, this function returns a lambda type for each lvar.

cps/convert.sml
     Fix the bug 618 and 619. No CPS.SELp is allowed before cpsopt phase.
     Partially add in the new converter which can take advantage of the
     type information when the System.Control.CG.representations flag
     is turned on. A new and cleaner convert module is expected in the
     next release.

codegen/opt.sml
     Change the linking interface, add appropriate type information
     in the closestr and closetop functions.

env/coreinfo.sig
env/coreinfo.sml
     Add a new coreLty reference cell which will tell you the type of
     the module Core. This is useful to find the type of any components
     in Core.

env/invenv.sml
     Add a Lambda.lty to the componantId type in the inverse
     environment.

env/environ.sml
     Change the function makeStaticEnv, VARbind is now also included
     in the inverse environment. This is useful when given a lvar at
     the linking interface, we need find out its static types.
     The function filterEnv now also takes the inverse environment.
     Originally the inverse is set to be empty.

env/prim.sml
     Let the function "special" return true for all inline primops.

modules/representation.sml
     Change the representation of the thinning interface to
     add appropriate type coercions when doing signature matching.

     Files affected by this:
        elaborate/elabstr.sml
        modules/moduleutil.sml
        modules/sigmatch.sml
        translate/translate.sml

modules/representation.sml
modules/abstractfct.sml
modules/applyfct.sml
basics/printbas.sml
translate/transbinding.sml
     Add a "fullstr" field to the body of the raw functor FCT in
     representation.sml. This field records the body signatures
     of any arbitrary raw functors. This info is useful for the
     representation analysis.

translate/transbinding.sml
translate/transtypes.sml
     Add utility functions on the new lambda types lty. All front end
     static information are converted by utility functions defined in
     these files into lambda types lty.

translate/mccommon.sml
translate/mc.sml
translate/tempexpn.sml
     Add appropriate type information into the decision tree in the
     match compiler. Coercions are inserted whenever to DECON a
     polymorphic data constructor (DELTAPATH).

translate/translate.sml
     The new translate module which produces the new intermediate
     lambda language. While compiling the whole compiler, the time
     spent in the translate phase in 89 is about same as that in 88.
     Also the bug 621 is fixed.

typing/typecheck.sml
typing/typecheck.sig
elaborate/elabstr.sml
     Change the type-checker to produce the new abstract syntax tree
     annotated with type information.
     The typecheck function decType now not only does the typechecking
     but also modifies the abstract syntax which carries the appropriate
     type information into the translate module and the backend.

--------------------------------------------------------------------------
Summary:


1 file (translate/mcopt.sml) was deleted from 88.
2 new files (translate/transtypes.sml,
             translate/transbinding.sml) were added into 89.
63 files were changed

List of files changed:

./all
absyn/absyn.sml
absyn/printabsyn.sml
basics/lambda.sml
basics/printbas.sml
basics/typesutil.sig
basics/typesutil.sml
boot/perv.sml
boot/system.sig
build/batch.sml
build/boot.sml
build/compile.sml
build/computil.sml
build/evalloop.sml
build/index.sml
build/linkage.sml
build/process.sml
build/prof.sml
codegen/interp.sml
codegen/lambdaopt.sml
codegen/opt.sml
codegen/reopen.sml
cps/closure.sml
cps/contmap.sml
cps/convert.sml
cps/cps.sml
debug/debugger.sml
debug/dprintabsyn.sml
debug/instrum.sml
debug/queries.sml
debug/static.sml
debug/util.sml
elaborate/elabcore.sml
elaborate/elabstr.sml
elaborate/elabutil.sml
elaborate/misc.sml
env/coreinfo.sig
env/coreinfo.sml
env/environ.sml
env/invenv.sml
env/prim.sml
modules/abstractfct.sml
modules/applyfct.sml
modules/instantiate.sml
modules/moduleutil.sml
modules/representation.sml
modules/sigmatch.sml
parse/ast.sml
print/printdec.sml
runtime/SPARC.prim.s
translate/equal.sml
translate/inlineops.sig
translate/inlineops.sml
translate/mc.sml
translate/mccommon.sml
translate/mcprint.sml
translate/nonrec.sml
translate/reorder.sml
translate/tempexpn.sml
translate/translate.sml
translate/unboxed.sml
typing/typecheck.sig
typing/typecheck.sml

(END OF NEWS.89)
--------------------------------------------------------------------------

-------------------------------------------------------------------------
Standard ML of New Jersey, Version 0.88, August 14, 1992


116 files were changed and 5 new ones added in this version.

1) Added support runtime support for RS6000

2) Closures are no longer created in the machine assembly files,
   but are created in C (see cstruct.c)

    - Lal
--------------------------------------------------------------------------

1) Changed the representation of labels used by the scheduler.

    - Andrew
--------------------------------------------------------------------------

1) Made vector into a primitive builtin type (to support typechecking
   of vector patterns and exprressions).

2) Removed uses of "syscall" in boot/perv.sml to improve portability.
   Added additional functions to runtime/cfuns.c to support the
   system calls that were previously implemented using syscall.

3) Added a tag to the RECORD constructor in the lexp and cps datatypes.
   This tag distinguishes records from vectors, so that vector expressions
   of length 2 get the right tag (i.e., they don't get the pair tag).

    - John
--------------------------------------------------------------------------

    Previously, when two user specified explicit type variables with
the same name occured in the same scope with different weakness or
equality requirements (i.e., both '1a and '2a in same scope), they were
considered different variables.  This is no longer the case.  Such
occurences now generate errors.

    A spurious duplicate type variable message is no longer printed.

    A new function, PrintType.tyvar_printname returns the print name
of a type variable as a string.  I.e., "'1a", etc.  This is now used
consistenly throughout the compiler to print out type variables.  This
had the result of removing a few inconsistenes like user bound variables
being printed without the U on the end and underscores not always being
used correctly when System.Control.weakUnderscores was true.

    - Mark
--------------------------------------------------------------------------
1) Change in the interface of CompileAst:

CompileAst doesn't require anymore to have the information about the fixity
of objects currently compiled because it rebuilds it and give it back
in its result.

Parse still gives back info about the fixity of objects compiled. It is
necessary only if the parser is called immediately on other files.

2) Changes in the treatment of signatures:

The behaviour of include in presence of type redefinition has been changed.
The redefinition of a type is authorised as long as it is not in conflict
with the previous definition on arity.

The purpose is to allow the inclusion of multiple signatures refering to a same
type not yet defined.

signature a = sig datatype 'a t = c of 'a val x: int t end
signature b = sig type 'a t val y: bool t end
signature c = sig type t end
signature d = sig datatype 'a t = c of 'a end
signature e = sig type 'a t val x: int t end

signature b' = sig include a include b end    O.K.
signature c' = sig include a include c end    error: arity of t
signature d' = sig include a include d end    error: redefinition by datatype
signature e' = sig include a include e end    error: redefinition of x

3) first class environment:

There is a new function filterStaticEnv: staticEnv * symbol list -> staticEnv
System.Env.filterEnv takes care of infixes.

4) bug fixes:

- the Ast is always marked even if System.Control.markAbsyn is set to false
so the compiler can give relevant error messages
- the printed name of types coming from a functor argument has been improved
- no more second effect bug when an object defined by the specification of
a functor body is in fact undefined in this body.
- System.Symbol.makestring is fixed

    - Cregut
--------------------------------------------------------------------------
1) Cleaned up and improved the pattern matcher.

2) Allowed for vector patterns and vector expressions.
   Vector expressions and patterns are introduced using #[.. ]

3) Provided hooks for templates.

    - Aitken
      (more details to be provided.)
--------------------------------------------------------------------------
all
build/debugger.sml -> debug/debugger.sml
  Moved to a more convenient subdir.

debug/debugger.sml
dbguser/commands.sml
dbguser/emacs.sml
dbguser/interface.sml
debug/exec.sml
debug/motions.sml
  Changed interface to interpolations.  Routine to set an interpolation now
returns normally; dbguser/commands.sml then arranges to execute the
interpolation immediately by performing a jump.

all
build/computil.sml
build/evalloop.sml [new]
build/inithooks.sml
build/interact.sml
cps/shareglue.sml
debug/debugger.sml
  Created a new EvalLoop structure to contain the guts of interactive
loop processing.  Routines in this structure take a large parameter record.
The Interact and Debugger functors now invoke these routines with
appropriate parameters.

dbguser/commands.sml
dbguser/interface.sml
debug/bindings.sml
debug/debugger.sml
debug/instrum.sml
debug/motions.sml
debug/queries.sml
debug/static.sml
  Changes to support breakpoints at "fine-grained" events, not just the heads
of coalesced event lists ("evn"s).  Instrumenter now produces an array of all
fine-grained events; type place (=int) point into this array.
Coalesced events are now represented as lists of places, and places are
by query routines in dbguser/interface.sml. Last binding event numbers are
no longer computed by instrum.sml nor stored by static.sml.

debug/instrum.sml
debug/static.sml
elaborate/elabutil.sml
parse/ml.grm*
  VAL, VALREC, RAISE, LET, and LOCAL events are reported at more
sensible locations; some additional marking of absyn is required.
Events from rules automatically added to raise Match exceptions or
complete handle matches are now located after last character of
previous rule, and are no longer returned by eventPlacesAfter/Before.

all
basics/symbol.sig
env/env.sml
debug/env.sml
modules/tabify.sml [new]
  Added support for debugger emulation of TABspaces, using
functions in tabify.sml to convert ordinary module bindings
into TAB bindings.  TABspace is split into four sub-spaces for
different module types.

boot/perv.sml
boot/system.sig
codegen/interp.sml
  Added cases to interpret SUBSCRIPTV, FSUBSCRIPTd, FUPDATEd, GETHDLR,
and SETHDLR to the interpreter.  This required adding all five of these
to System.Unsafe, and the latter two to the type-safe version of Inline.

debug/debugger.sml
debug/static.sml
  Fixed problem with maintenance of current index.

dbguser/debugperv.sml
dbguser/hstore.sml
  Fixed types of HistoricalArray functions.
  Removed tentative versions of HistoricalByteArray and HistoricalRealArray.

modules/debugmod.sml
  Fixed check for anonymous parameter name.

debug/debugger.sml
  Added type constraint case for ABSTYPEdecs.

dbguser/load.sml
  Revised and commented load sequence.

    - Tolmach-------------------------------------------------------------------------
Standard ML of New Jersey, Version 0.87, July 31, 1992

cps/closure.sml
   Reverted to its state as of 0.85.

runtime/SPARC.prim.s
   Fixed function logb to return 0 on argument of zero.

runtime/cfuns.c
   Fixed bugs in ml_blast_out and ml_exec.

All the other changes have to do with the debugger:

build/interact.sml
build/debugger.sml
cps/nullglue.sml
cps/shareglue.sml
debug/interface.{sig,sml} (removed)
m68/m68glue.sml
mips/mipsglue.sml
sparc/sparcglue.sml
vax/vaxglue.sml

A new file build/debugger.sml, defining a funsig DEBUGGER and functors
BogusDebugger and RealDebugger, now controls "top-level" features for
the debugger.  It replaces the existing debug/interface file and code
that was originally folded into build/interact.sml.
It uses the guts of interact and eval_stream in build/interact.sml, which
have been factored out and exported as routines interact0 and eval_stream0.
A DEBUGGER is now a parameter to IntShare; as before, the bogus version is
used when debugger support is excluded.  The per-architecture glue modules
have been changed accordingly.

env/dynenv.sig
env/dynenv.sml
env/invenv.sig
env/invenv.sml

  "Special" dynenv's and invenv's have been added to match special statenv's;
they are used by the debugger's interactive loop.

dbguser/userlevel.sml
dbguser/load.sml
makeml

  userlevel has been renamed to load, and makeml adjusted accordingly.

debug/calctype.sml (removed)
modules/debugmod.sml
typing/dyntype.sml

  File debug/calctype.sml has been replaced with two new
files supporting type reconstruction.  debugmod.sml is mostly hooks for
future.  dyntype.sml implements dynamic type reconstruction using callbacks
to obtain static types of actual arguments to polymorphic functions.

build/computil.sml
build/interact.sml
coder/coder.sml
cps/cpscomp.sml

  Changed signature of timemsg and added new utility function infomsg.

absyn/absyn.sml
absyn/printabsyn.sml
boot/perv.sml
build/index.sml
elaborate/elabcore.sml
print/printdec.sml
translate/translate.sml

   A new field ident is added to EBgen's to contain the expression to be
written into the exception ref.   This is explicitly filled by elabcore
to be the normal thing, i.e., the constructor name; translate now just
translates the expression normally.  Under the debugger, instrum.sml
alters the ident field to be a record consisting of (name,time created).
This allows the debugger to determine the type of the constructor argument
and print it correctly if an uncaught exception occurs.
File boot/perv.sml:exn_name has been altered to distinguish these two cases,
(the definition of the Tags structure has been moved up to make it useable
within PreLim.) Other files were changed to reflect adding ident.

debug/*
dbguser/*
  Added proper support for signals and for user-interpolated code fragments.
  Revised type reconstruction algorithm to obtain static types of arguments
  via explicit type annotations rather than (partially) reconstructing them
  at runtime.  Integrated support for most compiler changes since
  the late 0.60's  (but type reconstruction based on functor argument types
  still doesn't work).   Numerous bug-fixes.

elaborate/elabstr.sml
elaborate/frontend.sml
build/process.sml
build/compile.sml
build/interact.sml

  Added a "translate" pass to the parsing process, which occurs after
elaboration but before type-checking.  This allows the debugger to insert
explicit type constraints into the syntax to support dynamic type
reconstruction. Everywhere else, an identity transform is inserted.


parse/ml.grm
   Restored various forms of source marking that had disappeared since 0.75.

build/process.sml
   Added case to function comp to allow batch compilation of funsigs.

util/arrayext.sml
   Added new reset and refill functions; made minor efficiency hacks;
   removed misleading comments on "where used".

The following outdated or experimental files have been removed from
the release:

dbguser/normperv.sml
dbguser/system.sml
dbguser/timeit.sml
dbguser/usercommands.sml
dbguser/userlevel.sml
debug/bindings.sml.save
debug/bogusdebug.sml
debug/calctype.sml
debug/commands.sml
debug/historyio.sml
debug/historystore.sml
debug/instrumr.sml
debug/interface.{sig,sml}
debug/nstatic.sml
debug/nkernel.sml
debug/ninstrum.sml
debug/nbindings.sml
debug/nrun.sml


Why:

-------------------------------------------------------------------------
Standard ML of New Jersey, Version 0.86, July 22, 1992

From Appel:

Beware that the sparc,m68,and vax mo files each contain only enough
to build a self-compiler (batch or interactive), not a cross-compiler.
Beware also that the mo.mipsb are as compiled by a slightly earlier
version so you won't get fixed points equal to what's there.

The last remaining vax in our department is down indefinitely,
so I haven't tested the vax version (though the mo files are there).

The profiler now works.  see src/profile/README.

0.86 boots on the mipsb, sparc, and NeXT; and compiles itself on the mipsb.
I haven't done other tests.

Andrew's Changes from version 0.85 -> 0.86:

cps/generic.sml, util/intmap.sig, util/intmap.sml:
    Added new function "Intmap.clear" to delete all the entries
    from an intmap; generic now calls this from time to time,
    which cuts down greatly on its memory usage.

mips/instrset.sml, mips/mipsmc.sml, mips/mips.sml, etc.
    Made "register" an abstract type, so that it can be represented
    more compactly and thus save space during scheduling.

print/printdec.sml:
    Added a space to a string that was being printed.

cps/cmachine.sig, cps/generic.sml, mips/mips.sml, mips/instrset.sml,
    sparc/sparcdepend.sml, sparc/sparc.sml, vax/vax.sml,
    m68/m68.sml, runtime/MIPS.prim.s, runtime/SPARC.prim.s,
    runtime/M68.prim.s, runtime/VAX.prim.s, runtime/callgc.c,
    runtime/cfuns.c, runtime/run_ml.c:

    The register masks no longer sit right before the back-pointer.
    Instead, they are passed in a special register (on the stack
    for the VAX) to the g.c. routine.  This will make it easier
    (soon) to get rid of the backpointers entirely.

cps/eta.sml:
    Changed the uncurry optimization so that
        fun f(x) = let fun g(y) =  . . .
                        in g
                       end
        won't be uncurried if g is recursive.  Surprisingly, this worked
    in CPS; but it wasn't necessarily a useful optimization!

runtime/signal.c:
    Changed default handler for SIG_VTALRM per Tolmach's suggestion.

runtime/M68.prim.s:
    Made some changes that should have been made
    when version 0.84 with trapless g.c. was made.

basics/conrep.sml, boot/system.sig, boot/perv.sml, build/batch.sml:
    Added a flag "newconreps" to allow compiling with the
    new, more compact (but not quite Standard) constructor representations.

coder/machinstr.sig:
    deleted "eqtype register" which nobody used.

cps/closure.sml: [Zhong Shao, modifying Trevor's changes to closure.sml
         listed below]
    Eliminated closures of size one.

cps/knownfiddle.sml, cps/cpscomp.sml:
    New optimization, performed just before the closure phase,
    tries to avoid fetching variables from closures unless they're
    really needed.

cps/expand.sml, cps/cpsopt.sml:
    Improved "loop unrolling."
    Also, get rid of loop-invariant arguments of loop functions.
    If !System.Control.CG.unroll=false and CG.invariant=false
    then it should be equivalent to the old way.

profile/profile.sml, profile.profperv.sml, profile/script, profile/README
    Code to be loaded into an interactive system to enable use
    of the profiler.

runtime/Makefile:
    Added some missing dependencies.
-------------------------------------------------------------------------
Standard ML of New Jersey, Version 0.85, July 17, 1992

Major user visible changes:

    - The behavior of the type checker on flexible records has been
fixed.  This required altering how flex records were represented
internally.  Flex record types now in addition to having a weakness
level, also have an equality flag and a depth level (used to determine
when to generalize type variables).  This information is now displayed
when flex types are printed.  Sample outputs:

        {x:int,'a...}        1 field, x of int type,
                    not necessarily an equality type,
                    not weak
        {x:int,''a...}        as above but an equality type
        {x:int,'5a...}        as first one but at weakness
                    level 5
        {x:int,'a...[3]}    as first, depth is 3.  The depth
                    information is only printed when
                    System.Control.internals is true
                    and the depth is not infinity.

    The variable name before the "..." is to make it possible to
tell when two types contain the same flex record.  This is necessary,
for example, to tell where circularity occurs.

    - As part of the fix to flex records, a new unifier has been
installed.  The new unifier is somewhat better at preserving type
abbreviations during unification.  Other minor differences may be
noticeable causing slightly different but equivalent types to be
returned.

    - When expressions fail to type check, they are assigned type
WILDCARDty (previously called ERRORty) which matches anything.  This
allows type checking to proceed without causing redundant/spurious error
messages.  This type used to print as "error".  It now prints as "_" to
better reflect its meaning.

    - Non-strict type abbreviations are handled differently to avoid
some subtle bugs (see bug #'s 573 & 589 for example).  Whenever a type
defined using a non-strict type abbreviation is entered, the non-strict
arguments to the abbreviation are changed to wildcard types (_'s).  This
effects nothing except internal processing and how the type prints out
since those arguments go away anyway when the abbreviation is expanded
out.  Example:

        - type ('a,'b) FOO = 'a;    (* second arg. non-strict *)
        type ('a,'b)  FOO = 'a
        - fn x : ('a,'b) FOO => x;
        val it = fn : ('a,_) FOO -> ('a,_) FOO

    - type variables are now considered equal iff their name parts,
weakness parts, and equality parts are equal instead of if their input
forms where equal.  I.e., '01a and '1a are now equal whereas before they
were not.

    - the lexical definition of type variables have been changed to
prevent confusing cases such as '_1a.  The grammar is now:

    type_variable_name ::= '[']{weakness}{identifier}
    weakness ::= _ | <number> | <empty>
    identifier ::= <letter><alphanumeric(includes ', _)>*

    Examples:
        'a
        ''a
        '_abc            (* this is same as '1abc *)
        '45bc
        '_this_is_weak
        'not'this'one

    - When System.Control.weakUnderscore is true, all type variables now
have their weakness numbers (if any) replaced by "_" when printing.
Previously this only happened for some type variables (the IBOUND ones).


Major internal changes to the compiler:

    - The representation of types (type ty) was reorganized.  The IBOUND
case was made a type instead of a kind of variable since it is never
instantiated and does not need equality, weakness, etc., information
associated with it.  The FLEXRECORD case was made into a kind of
variable from a kind of type since it does get instantiated and does
need equality, weakness, etc., information.

    Variable information was reorganized to put the common
information (eq, weakness, depth) in the top level, instead of
duplicated in each of the cases to make processing easier and more
uniform.  ERRORty was renamed to WILDCARDty (see user changes for why).

    - To implement fixing the non-strict type abbreviations, a new
function TypesUtil.mkCONty was introduced.  This must be used to
construct CONty types anytime the tycon could be a DEFtyc or an ERRORtyc.
Failure to do this is an programming error.

    This routine when given a DEFtyc takes care of changing the
non-strict arguments to WILDCARDty's.  It does this using the strict
field of the DEFtyc which is now a bool list instead of just a bool,
telling exactly which arguments are non-strict.  When given an ERRORtyc,
mkCONty returns WILDCARDty.  This causes ERRORtyc to have the proper
matching behavior, etc.

    Note that this change fixes many (unreported) internal bugs.
This is because now expanding out type abbrievations and ERRORtyc's does
not alter the set of type variables in a type.  This means that, for
example, occurs checks can be done without needing to expand the type
abbreviation.  Since WILDCARDty's match anything & esp. themselves,
argumentwise comparison of two CONty's with the same DEFtyc is now
legal.  Also, routines scanning down types should never have to deal
with ERRORtyc anymore.

    - UBOUND variable names no longer contain the weakness and equality
info, only the name part.  (i.e., ''15abc has name "abc" instead of the
old "'15abc")

    - When a type constructor in a functor application fails to match
the specification, an ERRORtyc is stored instead of the constructor.
Specification matching has been fixed to allow WILDCARDty's to match
anything, removing some spurious error messages that used to be produced.

    - Two new utility functions were introduced:

    listofarray in ArrayExt
    zip2 in List2


Bug fixes:
    482. "constant" unary type abbreviations in signature matching
    468. extra comma in printing unit record
    521. type checking flex records
    533. typing record types
    569. failed type inference with flexible records
    570. flexrecord equality types
    571. no occurs check when instantiating flexrecords
    572. unify doesn't update depth for flex record types
    573. unifier detects spurious cycles with type abbrevs
    580. compileUnit bug in separate compilation
    588. wrong printing of flex records with no fields
    589. occurs check with nonstrict type abbreviations
    590. Some user type variable names are handled incorrectly.

-------------------------------------------------------------------------
Standard ML of New Jersey, Version 0.84, July 5, 1992

Andrew's Changes June 1992:

cps/expand.sml:
    Changed into a two-pass algorithm:  First try ONLY loop
    unrolling; then try everything else.
    If !System.Control.CG.unroll=false then it should be equivalent
    to the old way.

boot/system.sig, boot/perv.sml:
    Added new CG flag "unroll", doesn't do anything yet.
    Moved things to Hooks that should have been there already.
    Deleted the Profile and ProfileInternals structures.
    Deleted System.Unsafe.isolate.

build/interact.sml:
    Made a local version of "isolate" that checks for escaping
    top-level continuations.  (The old System.Unsafe.isolate
    did that PLUS made sure extra variables didn't put in the
    closure; the new safe-for-space system does that to every
    closure automatically.)

build/prof.sml, boot/loader.sml, build/interact.sml, build/computil.sml,
runtime/run.c
    New version of profiler no longer builds a lambda expression
    that returns (executable,profileInfo).  Now only the executable
    is returned; the profileInfo is automatically installed by the
    executable itself when it is run.

runtime/signal.c, boot/perv.sml, boot/system.sig
    Added SIGPROF and SIGVTALRM as ML signals.

blast_write returns size in bytes; blast_read now takes size in bytes:
Note for compatibility:
   fun old_blast_write(f,a) = (blast_write(f,a); ())
   fun old_blast_read(f) = blast_read(f, can_input f)


codegen/lambdaopt.sml:
Made lambdaopt accomplish what it has to do in one round instead of two.

cps/cpsopt.sml:
Eliminated the two rounds of contract before eta, no longer necessary
given trevor's eta-optimization in convert.

boot/math.sml
improved speed and accuracy of sine and cosine (except on vax)

boot/perv.sml:
improved speed of doing input(f,k) for very large k from quadratic to linear
    on NFS.  (Was already good on non-NFS filesystems)

env/prim.sml:
made INLUPDATE on integers avoid updating the store list

cps/reorder.sml: moved to translate/reorder.sml

translate/reorder.sml: see trevor's changes below; then I made it safe
for space by never moving a SELECT to the right of an APP.

build/computil.sml, coder/coder.sml, build/interact.sml, etc:
Improved gathering of timing statistics for summary.


Trevor's Changes June 1992:

CHANGED build/computil to print out versions of lambda if saveLambda
  is set.  There ought to be another flag for this.


CHANGED codegen/opt.sml: the function closestr defined in opt.sml sets
  up the header for the free structures referenced in a piece of
  lambda.  But it didn't check for duplicates; I fixed this.
  Also, the function "root" was duplicated as the function "last"; I
  removed "last".


Problem with codegen/lambdaopt.sml:
  lambdaopt will never remove a select, even if the result is not used.


LambdaOpt (codgen/lambdaopt.sml) is where the names of functions
  are getting lost: if they are used only once, it inlines them,
  completely losing the name (since functions are allowed to be
  nameless in the lambda language).


TO DO: at least rationalize the lambda printing a bit.  It shouldn't
  be controlled by saveLambda; there ought to be another variable.
  It would be nice if we could control just how far the compiler went
  (have it stop at any phase) and control exactly which phases
  do printing.


CHANGED cps/convert.sml: Newly-introduced eta-redexes are reduced
as soon as they are made, which makes the output of convert.sml 17% smaller.


CHANGED translate/mc.sml and translate/mcopt.sml so that the function
  for a rhs of a pattern which binds only one variable does not take a
  record of that one value as an argument, but rather just the value
  itself.  The change to mcopt was merely to a type definition, and the
  changes to mc were minor, consisting of "special case" code in two
  places, and some cleaning up.


CHANGED cps/reorder.sml: always leave VARs, INTs, REALs, STRINGs alone
  when they appear in records, never reorder APP(FN _,_) case.

CHANGED translate/mcprint.sml: minor fixes.  Affected use of printLexp
  in translate/mc.sml, possibly ought to change use of printLexp and
  printFun in build/process.sml, build/computil.sml, codegen/reopen.sml.


CHANGED runtime/MIPS.prim.s, runtime/cfuns.c, runtime/mask.h
  to fix no-callee-save/no-share bug.   This bug also caused
  the failure of 0.82 on the 68020.

CHANGED boot/perv.sml: minor change to printing of parse time in
  System.Stats.summary().

CHANGED build/computil to charge codeopt for the time spent in
  LambdaOpt.lambdaopt() and Reorder.reorder().


CHANGED lots of files to modularize the cps stuff.  Previously the
  convert phase was done in build/computil.sml, with some of the lambda
  stuff.  I've removed it from there and put it in cps/cpscomp.sml.
  There were lots of bogus changes because the types of signatures
  changed.  A detailed list of changes follows:


CHANGED cps/cpscomp.sml: cleaned up printing (messages, codesize,
  and the cexp's).

CHANGED build/batch.sml: removed duplicate flags printit and ifidiom.

CHANGED cps/size.sml: to print total as well as cells, descriptors.

CHANGED build/batch.sml: it now records codesize stat, just as does
  build/interact.sml.

CHANGED build/interact.sml: the function codegen was improperly
  charging time to the codegen phase; all the timing stats are kept
  in cps/cpscomp.sml.

CHANGED all: no longer compiles cps/closure1.sml.

DELETED cps/closure1.sml
    (its functionality was merged into cps/closure.sml)

CHANGED cps/cpscomp.sml: to get rid of ClosureCallee special case.

CHANGED cps/profile.sml, cps/closure1.sml, cps/spill.sml,
        cps/cpscomp.sml, build/batch.sml, all
  Reimplemented allocation profiling; renamed profile.sml to
  allocprof.sml.  The type of closeCPS and spill have changed; they no
  longer take a profiling hook.

CHANGED runtime/run_ml.c
  To set up varptr for allocation profiling.

CHANGED makeml
  To add -g flag.

CHANGED boot/perv.sml, boot/system.sig, build/batch.sml, cps/closure1.sml
  Changed flag System.Control.CG.profile to System.Control.CG.allocprof.

CHANGED boot/perv.sml, boot/system.sig, build/batch.sml, build/computil.sml,
  Added flag System.Control.CG.printLambda.

CHANGED boot/perv.sml: loop unrolling of @, map.

CHANGED cps/generic.sml: moved code that counts known/escaping
  functions into closure.sml

CHANGED cps/contmap.sml, cps/freemap.sml: for closure changes.

---------------------------------------------

Interesting or useful things to do:

Write paper about efficient cps conversion.

Improve lookup in closure phase to make compilation faster.

Measure register targeting to see if that's really the problem.

Better optimize net size of callee-save continuations

Do safe-for-space linked closures

Fix Reppy's bug:
    For each fix F defining an escaping function whose body
    calls a known function h, inverse-eta-reduce h' in the same fix

Do better register/closure allocation.


-------------------------------------------------------------------------
Standard ML of New Jersey, Version 0.83, June 12, 1992

Higher Order Functors
---------------------

Functors can be declared inside structures. Therefore, they can be
arguments or results of other functors.

Functors can be described by functor signatures. A functor signature
is specified in the following way:

funsig <ident>(<argument specification>) = <signature body>

- <ident> identifies the name given to the functor signature,
- <argument specification> specifies the formal parameters. It has
  the same syntax as formal argument specifications in functors,
- <signature body> is a regular signature body (i.e. either a
  signature variable or a sig ... end expression).

In signatures, functor signatures must be used to specify functor components.
The syntax of a specification is the following:

functor <ident functor>: <ident funsig>
functor <ident functor> (<argument specification>) : <signature body>

A functor can now be declared in two different ways:

- full definition of the argument and the body:
functor <ident functor> (<argument specification>): <optional signature body> =
  <structure body>
- restriction of an already existing functor:
functor <ident functor> : <optional functor signature ident> = <functor ident>

They can be used either at toplevel or inside a structure.

Abstract syntax trees
---------------------

An external version of SML raw abstract syntax trees is now available.
The corresponding datatype is defined in System.Ast .

Two functions are provided to use it with the compiler. They are defined in
System.Compile .

- val parse       : source * staticEnv -> ast * staticEnv
takes a source describing an input stream and gives back the ast of the
expression contained with an environment containing informations about
the infix variables defined.

- val compileAst  : ast * staticEnv -> compUnit
takes an Ast and an environment to interpret it and produces a compiled unit
that can be executed.

Infix annotations are built by the functions infixleft and infixright.


New files to support higher-order functors and exported
abstract syntax:
  elaborate/elabcore.sig
  elaborate/elabcore.sml
  elaborate/elabsig.sig
  elaborate/elabsig.sml
  elaborate/elabstr.sml
  elaborate/elabutil.sig
  elaborate/elabutil.sml
  elaborate/frontend.sml
  elaborate/misc.sig
  elaborate/misc.sml
  elaborate/normalize.sml
  elaborate/tyvarset.sml
  modules/extern.sml
  modules/modules.sig
  modules/modules.sml
  modules/representation.sml
  parse/ast.sml
  parse/astutil.sig
  parse/astutil.sml

Deleted files:
  absyn/bareabsyn.sig
  absyn/bareabsyn.sml
  modules/sigmatch.sig
  parse/corelang.sml
  parse/misc.sig
  parse/misc.sml
  parse/normalize.sml
  parse/parse.sml
  parse/signs.sml
  parse/strs.sml
  parse/tyvarset.sml
-------------------------------------------------------------------------
Standard ML of New Jersey, Version 0.81, 15 May 1992

**************************************************************************
                WARNING
**************************************************************************
This is a development version of Standard ML of New Jersey.  As such it
is untested and may be broken in various serious ways.  For instance, this
version will not build on M680x0 based machines.  Use at your own risk.
**************************************************************************


   - New GC linkage mechanism summary:

    limit checks only on minimum feedback vertex set
    limit checks by conditional branch.  Address of saveregs at fixed
     position in stack frame.  Address of limit check in register 31
     (or %o7, or whatever).
    Register "stdlink" used to pass address of any non-continuation escaping
     function being called (also address of non-callee-save continuations
     function code pointers).  For known funcs, stdlink can be used as
     ordinary register just like stdarg, stdcont, etc.  This eliminates need
     for bltzal or call instruction to get program counter.
    For callee-save continuations, the code address is passed in the stdcont
     register (where it was already sitting).
    The closure phase now makes the stdlink register an explicit argument,
     so the arguments for standard non-continuations are:
       stdlink stdclos stdarg stdcont [ calleesave1 calleesave2 ...]
    and the arguments of standard continuations are:
       stdcont stdarg  [ calleesave1 calleesave2 ...]



  - made the objlength primop visible as System.Unsafe.objLength

  - added the Fail exception to General

  - restored "use" to General

  - new primops for handling "special" objects (weak pointers and
    suspensions).  Added the structure System.Unsafe.Susp for the
    supporting suspensions, and removed force and delay from Unsafe.

  - added gettag primop and modified polyequal to use it.  Polyequal
    is now ready for the new GC.

  - 'makeml sgi3', for SGI running IRIX 3.3.x and, 'makeml sgi'
    for ANSI C conforming IRIX (i.e. 4.0.x)

Bug fixes:
    448. failure to build on MIPS 6280
    488. wrong types in pervasives
    498. bad function type in perv.sig
    520. broken under IRIX 4.0.1
    522. redundent patterns in compiler
    546. System.architecture not initialized
    551. large integers yield Illegal instruction
    xxx. space leak.
-------------------------------------------------------------------------
Standard ML of New Jersey, version 0.80, April 2, 1992

1. WARNING!!! -- Import gone.

The "import" keyword and the old import-style separate compilation
have been removed.  src/sepcomp no longer exists.  For separate
compilation, use the new version of sourcegroup (V2.0) available soon
from CMU.  This new version will rely on the new environment and
compilation structures described below, as well as the new persistent
stamps.


2. First class environments
   System.Symbol and System.Env have been added with signatures:

    signature SYMBOL =
    sig
      type symbol
      val valSymbol : string -> symbol
      val tycSymbol : string -> symbol
      val sigSymbol : string -> symbol
      val strSymbol : string -> symbol
      val fctSymbol : string -> symbol
      val fixSymbol : string -> symbol
      val name      : symbol -> string
      val makestring: symbol -> string
      val kind      : symbol -> string
    end

    signature ENVIRONMENT =
    sig
      type environment
      type staticEnv
      val emptyEnv     : unit -> environment
      val concatEnv    : environment * environment -> environment
      val layerEnv     : environment * environment -> environment
      val staticPart   : environment -> staticEnv
      val layerStatic  : staticEnv * staticEnv -> staticEnv
      val filterEnv    : environment * symbol list -> environment
      val catalogEnv   : staticEnv -> symbol list
      val describe     : staticEnv -> symbol -> unit
      val pervasiveEnvRef : environment ref
      val topLevelEnvRef : environment ref
    end

The strings returned by Symbol.kind are a bit unwieldy.  They could be
shortened, but it may be better to externalize the namespace datatype and
have replace Env.kind with a namespace function.  See note on
Environments and Compilation (doc/compile.doc).


3. Compilation

The new structure System.Compile provides the basic hooks for separate
compilation.  These facilities should support a type secure
replacement for the current batch compiler and should be used in the
bootstrap process as well.  The signature is:

    signature COMPILE =
    sig
      structure IO : sig type instream type outstream end
      type source
      type staticUnit
      type codeUnit
      type compUnit
      exception Compile of string
      val makeSource  : string * int * IO.instream * bool * IO.outstream -> source
      val closeSource : source -> unit
      val changeLvars : staticUnit -> staticUnit
      val elaborate   : source * staticEnv -> staticUnit
      val compile     : source * staticEnv -> staticUnit * codeUnit
      val execute     : (staticUnit * codeUnit) * environment -> environment
      val eval_stream : IO.instream * environment -> environment
      val use         : string -> unit
      val use_stream  : IO.instream -> unit
    end

Note that use and use_stream have been moved to System.Compile, which
is not open by default.  An environment based eval_stream has been
added.  These three functions use the top-level evaluation loop and
can handle arbitrary ML input.  The other compilation functions
(elaborate, compile, execute) handle only module declarations.

NOTE: "use" has been bound at top level in the makeml startup script,
but "use_stream" is not bound at top level and must be referred to as
"System.Compile.use_stream."


4. Dynamic environments.

The implementation of dynamic environments (DynamicEnv in env/dynenv.*)
is slightly incomplete.  The remove function is not fully implemented.
This implementation is supposed to be replaced by a purely applicative
version of dynamic environments.


5. Persistent stamps.

Persistent stamps have been implemented by Emden Gansner.  These allow
open structures and functors (i.e. structures and functors with free
references to other modules) to be separately compiled in a type-secure
way.


5. Top level loop.

The toplevel loop in build/interact.sml has been simplified.
Debugging hooks have been deleted and will have to be restored, one
hopes in a cleaner fashion.

The isolate function is still used.  It could possibly be simplified
or eliminated, but the code to verify the top-level context of
continuations is still necessary (see bug 145).

The interface to the profiler could possibly be simplified.


6. Changed files.

The following files changed between 0.79 and 0.80.

absyn/bareabsyn.sig
absyn/bareabsyn.sml
absyn/printabsyn.sml
basics/basictypes.sig
basics/basictypes.sml
basics/symbol.sig
boot/perv.sig
boot/perv.sml
boot/system.sig
build/batch.sml
build/boot.sml
build/compile.sml
build/computil.sml
build/freelvar.sml
build/index.sml
build/inithooks.sml
build/interact.sml
build/linkage.sml
build/process.sml
codegen/opt.sml
codegen/reopen.sml
cps/shareglue.sml
debug/env.sml
env/coreinfo.sig
env/coreinfo.sml
env/dynenv.sig
env/dynenv.sml
env/env.sml
env/environ.sig
env/environ.sml
env/invenv.sig
env/invenv.sml
env/prim.sml
env/statenv.sig
env/statenv.sml
lex/ml.lex
lex/ml.lex.sml
modules/moduleutil.sig
modules/moduleutil.sml
parse/base.sml
parse/ml.grm
parse/ml.grm.sig
parse/ml.grm.sml
parse/parse.sml
print/printdec.sml
sepcomp/sepcomp.sml
translate/translate.sml
util/intmap.sig
util/intmap.sml


7. Building 0.80 booting from earlier versions

Before compiling 0.80 with an earlier version of the compiler.

1. comment out the body of the InitHooks functor in
build/inithooks.sml.

2. temporarilty redefine the Compile exception in the CompileUnit
functor as
  exception Compile of string

3. temporarily redefine the topLevelEnvRef and pervasiveEnvRef
variables as
  val topLevelEnvRef : environment ref = ref emptyEnv
  val pervasiveEnvRef : environment ref = ref emptyEnv

After compiling with ~mBoot commented out, copy the Initial.mo,
Math.mo, and CoreFunc.mo files from the earlier compiler into
the new mo directory.  Then rebuild the batch compiler

1. remove comments in build/inithooks.sml

2. restore original definition of exception Compile in build/compile.sml

3. restore original definitions topLevelEnvRef and pervasiveEnvRef in
env/environ.sml

4. remove comment from ~mBoot line in all file.

and recompile.-------------------------------------------------------------------------
Standard ML of New Jersey, Version 0.79, April 1, 1992.

New object descriptor format

Datatype representation optimization disabled

New update primops

fnegd and real primops

Polyeq now knows that 0.0 and -0.0 are equal (because of new tags).


limit checks now done by conditional branch instead of trap

most known functions don't have limit checks (or backpointers,
           or register masks) any more.

blast_write fixed to allow several sequential blasts to same file.

-------------------------------------------------------------------------
Standard ML of New Jersey, Version 0.78, February 26, 1992 (batch compiler)

1. The mips code generator has been rewritten to use a machine
independent scheduler, with a novel algorithm for scheduling
in the presence of span dependent instructions. The new code
generator is 41% faster than v0.77 and allocates 67% of the
memory allocated by v0.77.

A summary of some important numbers when  compiling the compiler
upto parse/parse.sml on a mips magnum (walrus) is shown below:

               0.75      0.76     0.77     0.78
    ---------------------------------------------------------------
    user time (sec)        1278      2500     1268      901
    sys time  (sec)          18        33       19       18
    gc time   (sec)         370       601      310      302
    minor collections        2689      4506     3563     3365
    major collections          55        70       49       60
    allocation (bytes)   8115828  17521624  9697719  6138500
    code size (bytes)    1189392   1194924  1295172  1347912

-------------------------------------------------------------------------
Standard ML of New Jersey, Version 0.77, February 24, 1992 (batch compiler)
1. Separate compilation:
The compiler now supports the separate compilation of structures,
and the loading of separately compiled modules containing free
references to other structures and functors.


2. Fixed safe-for-space bugs.
The "bugs" were:

    1.  improper hoisting in making "recordpath" optimizations in cpsopt
    2.  improper hoisting, moving SELECT expressions downward in lambdaopt
    3.  callee-save closure sharing

The graph shows the amount of live data during each phase
of the compiler.  The input file is perv.sml.  The X's show the size
of live data at a major collection during the given phase; the vertical
bars | show what happens in a different run with an improved version
of the lambdaopt and contract phases.

The *'s show what happens when the executable code for the compiler
itself has been compiled using "safe-for-space" techniques.

         each X represents 100 Kbytes of live data

parse        XXXXXXXXXXXXXXX*XXX|
semantics    XXXXXXXXXXXXXXX*XXX|
translate    XXXXXXXXXXXXXX|XXX
lamopt/cnvrt XXXXXXXXXXXXXXXXXX*XXXXXXXXX|XXX
contract     XXXXXXXXXXXXXXXXXXXXXXX*XXXXXXXXXXXX|XX
closure      XXXXXXXXXXXXXXXXXXXXXXXX*XXXXXXXXXXXXXXXXXXX|XXXX
generic      XXXXXXXXXXXXXXXXXXXXXXXXXXX*XXXXXXXXXXXXXXX|XXXXXXXXXXXX
assemble     XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX*XXXXXXXXXXXXXXXXX|X


3. Data Representation Changes:

In compiling the compiler, it appears that g.c. time goes from
846->788  (7% savings) and total execution time goes from
3839->2882 (25% savings).

-------------------------------------------------------------------------
Standard ML of New Jersey, Version 0.76, 10 October, 1991

Beta reduction of functions called only once is performed
on the lambda representation. Also functions never used are
eliminated. (See file codegen/lambdaopt.sml)

The PRIMOP constructor for cps expressions has been broken
up into BRANCH, SETTER, LOOKER, ARITH and PURE.
(See the file cps/cps.sml)

All frontend primop names have been capitalized. Some name changes have
also been made, e.g. fadd is now FADDd ..., eql is now POLYEQL,
+ is now IADD, etc. (See file basics/access.sml)

cmachine instructions cvti2d and fnegd has been introduced on all machines
except the mips. (See cps/cmachine.sig)

The real primop (int -> real) has been implemented in terms of
cvti2d but is not presently used. (See cps/generic.sml)

Bugs fixed:

455 - failure to handle Real.Div - sparc scheduling problem
456 - corrupted heap with preemptive threads - error in callee saves fp regs.
457 - type reported for Real.ceiling was wrong - no types for InLine.cast
459 - infinite loop in signature matching
460 - identical to 459
-------------------------------------------------------------------------

Standard ML of New Jersey, Version 0.75, 11 November, 1991

Bugs fixed:
451. sharing constraints
453. unhandled exception crashes sml
-------------------------------------------------------------------------

Standard ML of New Jersey, Version 0.74, 10 October, 1991

Changes since 0.70:

  System.system now has the signature
    val system : string -> int
  where it returns the Unix status code of the sub-process.

  The IO.execute function has a different signature and two forms:
    val execute : (string * string list) -> (instream * outstream)
    val execute_in_env : (string * string list * string list)
          -> (instream * outstream)
  The first of these allows command-line arguments to be passed
  to the  program; the second also allows an environment to be
  specified.  In both cases, the base name of the first argument
  is prepended to the argument list.

  The module system has been reimplemented.

  Structure Compile added to pervasives to support Gene Rollins'
  sourcegroups separate compilation system.

Bugs fixed:
253. SML Dumping core compiling mlyacc with -pervshare
274. weakness lost with flex record pattern
283. openread (run.c) checking
294. weak polymorphic types
306. list printing, printlength
321. top level polymorphic exceptions allowed
334. adjust_limit in M68.prim.s
335. Dave Berry's library won't compile
337. double error message
342. execute destroys the unix-environment
354. SIGILL bug on SPARC (actually fixed in 0.70)
393. type abbreviations not transparent
407. create_v_v for SPARC
410. inlining property not preserved in simple renaming
413. System and IO problems
414. getWD wrong
418. repeated type names in type declarations
419. Runbind
422. overflow on int to real conversion
424. IO.execute on SPARC
426. type printing
427. Compiler bug: defineEqTycon/eqtyc
431. ml_writev
432. corrupted (shell) environment
433. lexgen bug
435. patrow syntax
439. lexgen
441. parsing large positive integers
444. large constants and Overflow
447. identity type abbreviation

----------------------------------------------------------------------
Standard ML of New Jersey, Version 0.73, 10 September 1991

Changes since 0.70:

Arrays now follow the new "standard" agreed on by all implementors:
structure Array is no longer open by default, sub must be infixed
by the user. There is also a new Vector structure for immutable arrays.
See doc/array. Floating arrays have been implemented.

Two new primops have been added to support floating arrays
and an assembly routine for vector creation.

The module system is internally rewritten, and should be more
robust and efficient.

System.Control.timings used to print timings
under the title 'codegen:' twice. One was really generic
and the other was the sum from convert through to the end
of scheduling/backpatching. The first is renamed to be 'generic:'.

Large number of changes have been made to the runtime system
to support multiprocessing. The main change is that all runtime
globals have been added to the MLState vector. A pointer to the
MLState vector is saved on the stack and is now passed as an
arguement to all the runtime routines  that uses its components.

Multiprocessing specific support routines (e.g., g.c.) have
been added.


Bugs fixed:

4. duplicate specifications not checked
242. incorrect forward referencing allowed
267. sharing again
276. overriding included value spec
277. incorrect "inconsistent equality property" error
280. included infix specs not printed
281. Import bombs out when it can't find files.
296. patch for HP/MORE
301. Compiler bug: tycPath
303. bad error reporting
304. SIGEMT on sparc
307. signature matching in 0.69
319. bad weakness degree (not weak enough)
324. bulletproofWrite dies in a bad way when out of disk space
330. comments bug
349. function names in FUN not checked for uniqueness
359. indexing
361. Error: Compiler bug: Functor.applyFunctor.insttyc
365. fixed size of tuples causes bug
366. lookahead
368. missing exceptions
369. bug in MLYACC
370. Wrong definition of div & mod in perv.sml
373. bug in printing fully qualified structure names
374. mod overflows on some negative numbers
377. prop.sml has bug
378. Error: Compiler bug: Functor.applyFunctor.redoTycs 1
382. missing \n on infix echo
383. open in nested structures fails with "Runbind"
386. printing bug with abstype
391. truncate
400. problem parsing weak types
404. std_out not flushed on read from std_in
405. identifiers starting with underscores are incorrectly allowed
406. funny signatures in 0.71

--------------------------------------------------------------
Standard ML of New Jersey, Version 0.70, 1 July 1991

Changes since 0.69:

Support for NeXT version 2.0.

Callee-save registers (for 7% better performance on MIPS and 18% on SPARC).

In-line array update and subscript (for 25% better performance on
"real" programs that use arrays; program that do nothing but array accesses
are twice as fast).

Experimental new primitives "getvar" and "setvar" intended for use
in multiprocessor versions of SML/NJ.

Bug fixes:
86. incorrectly allows redefining of "="
221. profiling broken
272. generalizing user bound type variables
276. weak polymorphism
286. Compiler bug: inststr NULLstr
308. Mips RC6280 code generation bug  (but 6280 still has other problems)
309: NeXTstation exported image doesn't work
320. bad weakness degree (too weak)
347. dec function in fastlib wrong
348. connect_inet bug
351. gc messages bug
352. gc statistics bug
363. bug in 0.69 interpreter
364. bug in lexgen doc
380. regbind compiler bug
384. signal handler never re-installed
389. stats
397. Unsafe.update with constant
Various flake-outs with ML signal-handlers have been fixed.
---------------------------------------------------------------------
Standard ML of New Jersey, Version 0.69, 3 April 1991

Changes since 0.66:

Floating-point programs should run twice as fast (thanks to Lal George).

Conforms more closely to the syntax in the Definition, so that
1+if... doesn't work anymore; use parentheses:  1+(if...)
Similarly for "case" and "fn".

New primitives "capture" and "escape" that are like callcc
and throw but do NOT preserve the exception handler of the saved
continuation.

Hexadecimal integer literals like 0x5e48.

Lots of minor bug fixes:

231. equality property of DEFtyc
243. include compiler bug
288.  extraneous "match not exhaustive" warning
289. 0.65 prerelease  core dumps
295. Compiler bug: r_o in mcopt
300. uncaught exceptin RegBind
305. Strange floating point error
311. abstype bug
318. rebinding of type operator "*"
326.  very big arrays
327. large constants cause overflow in compilation
328. callcc not tail recursive
329. checkopen broken
331. type variable generalized wrongly
333. code generation bug
339. type = allowed
357. import broken
358. import & pervasives
362. missing primop in interp
367. Decstation mach recompolation to m68
372. open in signature causes compiler bug
375. overflow bugs
376b. parsing
385. SIGHUP, SIGQUIT, SIGTERM ignored sometimes
387. arrays on Sparc
388. * as label of record
392. two type constraints
394. strange message in 0.66 typechecker
396. unbound variables should have type ERRORty
399. Vax dumps core
401. Imperative types in SML/NJ 0.66
403. 0.0/0.0 not properly handled
---------------------------------------------------------------------
Standard ML of New Jersey, Version 0.66, 2 October 1990

Changes since 0.65:
1) added exception Interrupt to General.  This was done so that programs
  that use Interrupt in patterns won't break.  The exception is NEVER
  raised by the run-time.  The signals mechanism should be used to handle
  SIGINT, but see doc/SIGINT for a simple way of modifying a top-level
  loop to deal with SIGINT.

2) added the function "pause" to System.Signals.  This is essentially the
  UNIX sigpause(2) system call.  It blocks SML until a signal occurs.

3) The BASICIO signature (which was empty) was removed from perv.sig.

Bug fixes:

275. illegal token with structure named ?
277. incorrect "inconsistent equality property" error
279. big integers causing uncaught exception
287. cosine function incorrectly defined
---------------------------------------------------------------------
Standard ML of New Jersey, Version 0.65, 10 September 1990

New features:

A new outstream, std_err, has been added to the IO structure.  It is
connected to the standard UNIX error stream.

There is now a general mechanism for handling UNIX signals.  The file
doc/papers/ml-signals.ps is the postscript for a paper that describes
the mechanism (Cornell University TR 90-1144).

Bugs fixed:  (complete descriptions are in doc/masterbugs)
223. nontty standard input and uncaught exceptions
232. user bound type variable in exception declaration
234/261. Compiler Bug: abstractBody.abstractType 1
235. repeated type variables in typdesc and datdesc
241. sharing constraint error ignored
244. compiler bug on product of large integer constants on SPARC
245. NeXT installation problem
247. close_out std_out [not considered a bug]
250. interpreter broken
251. omits tests for repeated bindings
255. space leak with redeclaration of variables
256. mcopt compiler bug with improper function definition
258. System.Directory.cd failure
262. Using the LIBRARY with v0.62 (Runbind)
263. problem with input via datakit con
265. strong type variables accepted in exception declarations
266. Io exception raised by "use"
268. import, equality
269. failure in abstractBody with embedded signature
270. Compiler bug: TypesUtil.lookTycPath: NULLstr
271. secondary compiler bug

---------------------------------------------------------------------------
Standard ML of New Jersey, Version 0.64, 25 August 1990

The compiler and user programs should use a bit less memory, as the
collector finds more garbage.  Compilation is faster, and there
are significant performance improvements in the SPARC and MIPS code
generators.

A preliminary version of the ML debugger, thanks to Andrew Tolmach,
is released with this version.  See doc/debug and lib/emacs for
details.  Warning:  using the debugger increases memory requirements
and compilation time substantially.

Bugs fixed:  (complete descriptions are in doc/masterbugs)
12. loss of information in value printing
182. uncaught exception after exportFn
185. exportML size  (negative percentages in g.c. messages)
186. type error matching against bogus tycon
205. performance problem with many opens in a structure
208. bug in optimizer causing bad free variable
213. equality on int*int  (new with 0.56)
214. Compiler bug: EnvAccess.lookPath when printing  (new with 0.56)
215. sin gives incorrect values
216. floating point on SPARC
217. simultaneous opens  (new with 0.56)
218. compiler bug after unbound variable  (new with 0.57)
220. Match exception after error
225. import broken in 0.59
227. equality property of datatypes
230. printing reals on mips
231. equality property of DEFtyc
233. opening locally declared structure causes Runbind
236. Mach problems in 0.59
237. Can't parse most-negative integer constant
238. div is unreliable at extremes
239. INCONSISTENT exception raised in sharing analysis
240. concrete printing of abstype value
243. include compiler bug
248. abstract types are not abstract
249. separate compilation printing problems
252. include broken in 0.59  (simplified version of 243.)
254. failure to detect type error
260. failure to raise overflow

---------------------------------------------------------------------------
Standard ML of New Jersey, Version 0.56, April 1990

The system now runs on MIPS-based computers:
    - MIPS computers running RISCos    (makeml -mips -riscos)
    - DEC 5400, 3100, 5800, etc. running Ultrix  (makeml -mips -bsd)
    Thanks to Norman Ramsey for this implementation.

Installation note:  The makeml script has changed slightly; look at makeml.1.

We have re-arranged our initial environment to conform better to
the Definition of Standard ML.  In particular:

Arithmetic exceptions:
    Sum, Prod, Diff, Neg, Exp, Floor are all equivalent to Overflow
    Div and Mod are equivalent, distinct from Overflow
    Ln is a distinct exception; Sqrt is a distinct exception
   The exception "Real of string" is gone.  Real overflows raise Overflow,
    real underflows return 0.0 with no exception, and real divide-by-zero
    raises Div.
Div and Mod:
    Now work according to the definition, but are much slower.
    The old (faster, rounding towards zero) behavior can be had
    by using the new infixed operators, "quot" and "rem".
Input and output:
    The functions input and output are now uncurried:
        output: outstream * string -> unit
        input:  instream * int -> string
    There are two new functions:
        outputc =  curry(output)
        inputc:   a curried input function, but with a difference:
            inputc f n
            returns "" on end-of-stream, and otherwise
            returns a string of length k, 0<k<=n,
            depending on what is available and convenient.

Remaining deviations from the Definition:

- The arithmetic overflow exceptions are all identified (see above).
- Strings carried by the Io exception are more informative in SML-NJ.
- Different right-associative operators of the same precedence
    associate to the right in SML-NJ.
- The @ operator is right-associative in SML-NJ.
- "local" and "open" specs in signatures have a different semantics
        (see doc/localspec)
- The symbol "=" can be re-bound (though usually you get a warning message)
- The construct   val ... and rec ...   is not permitted; the "rec"
    must immediately follow the "val".
- The Definition prohibits some, but not all, signatures that could
    never be matched by any structure.  We are more liberal about
    such signatures.
- The initial basis is a superset of the one described in the Definition.

The System structure in the initial environment has been re-arranged
slightly; see src/boot/system.sig.  In particular, "cd" is now
accessible as System.Directory.cd.

We know of two operating system bugs:
        A floating point exception will hang the machine in Ultrix V3.1A
   (Rev. 26) on the DEC 5400. This is an older release of Ultrix,
   and newer versions fix the problem.
        The "select" system call is unreliable on pipes in RISCos 4.20;
   as a result, you may have to press carriage-return after control-C
   to generate an interrupt.  We have reported this bug to MIPS.

Bugs fixed:  (complete descriptions are in doc/masterbugs)

26. export ML within a use
36. overloading resolution and order of recursive definitions
40. Exception aliasing (match compiler)
46. equality type checking and flexrecords
68. spurious error message -- doesn't match sig spec
69. printing of exn spec in inferred signature
70, 204.  constructor shouldn't appear in printed structure signature
72. equality types with abstype declarations
80. simultaneous type declarations
85. bad error message for failed signature match
101. Duplicate labels (in either types or values) are not detected
102. One-tuples are not printed sensibly.
103. Space missing in an error message (which might be more informative).
104. Labels with leading zeroes should not be accepted
106. Something strange is happening with "it".
107. NJML disappears ... when trying to parse large real numbers
108. More faulty error recovery?
109. sharing of datatypes not handled properly
117. sharing and equality attributes
118. deviation from Definition, div and mod
119. deviation from Definition  (input and output curried)
122. Unimplemented parts of Standard  (let and local for structures)
123. error recovery
124. compiler bug after incomplete qualified identifier
126.  scope of explicit type variables
127. sharing and equality types
128. question mark as reserved word
133. overloading resolution is weaker than Edinburgh SML or Poly ML
135. eqtype vs abstype
138. numeric labels not equivalent to tuples
140. comment to end of file  (see also bug 64)
141. interrupting gc dumps core
151. can't limit length of list printed
       System.Control.Print.printLength : int ref
       now controls number of elements printed in a long list.  Default is 12.
153. interrupting coroutine loop dumps core
155. Compiler bug caused by of missing structure
160. errorty fails to match sig spec
167. repeated bound type variables in type declaration
169. inferring eqtypes in signatures
171. illegal datatype declaration accepted
172. functor subscript error
173. Runbind
174. import and types
177. clinkdata on sun 3
179. compiler bug (783 in sigmatch)
181. 8-bit characters not supported in strings
183. "raise" not synchronized with evaluation sequence
187. parsing clausal definitions with infix functions
188. infinite loop parsing simple functor declaration
190. unclosed string in interactive system
191. Real operators permuted
192. bad parsing
193. import types
194. weak type variable syntax
195. Compiler bug: abstractType
196. Compiler bug: generalizeTy -- bad arg
197. exportFn size
198. printing exception specs in signatures
200. large interger literals
203. printing of infix specs in signatures
*.   Bugs concerning the relation of functor-result signatures to
       functor-parameter signatures are fixed.
*.   The most-negative-integer can now be printed without overflowing.
*.   Warning messages from the match compiler, the overloading resolver,
       and the typechecker pinpoint the site of the error much more accurately.

Bugs re-classified:  (complete descriptions are in doc/masterbugs)
7. constructor representation
    This now gives an error message when a user stumbles across it
    (which is exceedingly rare).  Also, we believe this is an inherent
    problem with the language, not with our compiler.
10. exhaustiveness message at top-level.
    This is a feature.
20. "print" is overloaded rather than polymorphic
    This is a feature.  The Definition makes no mention of "print".
24.  incomplete write
    This is removed from the list; our new signal-handling
    system provides more appropriate primitives to solve this problem.
86, 132. incorrectly allows redefining of "="
    Perhaps we should fix this, but it's not important to us.
87. execute subprocess dies on interrupt on blocked input
    This is a feature (of Unix), not a bug.
105. Large numeric labels are disallowed.
    Tough luck.  We're not going to fix this.
110. val rec
    This is a silliness in the Definition; we're not going to "fix" it.
111. local polymorphic definitions
    This is not a bug; if we allow this, the type system is unsafe:
     local exception X of '_a in val exn0 = X(3) fun h(X(b:bool)) = b end;
     raise exn0 handle e => h(e);
115. cyclic signatures
    We reserve the right to accept some signatures, even if there's
    no structure that they could match.
116. pattern declares no variables warning (?)
    This is a feature.  Can't you tell?
120. deviation from Definition (arithmetic exceptions)
    This is fixed, after a fashion;  see above.
121. Unimplemented parts of Standard (open specs)
    See doc/localspec
122. Unimplemented parts of Standard (local specs)
    See doc/localspec
164. NS32 in makeml
    We are not currently supporting the NS32000 architecture,
    but we may again support it with cooperation from users.

The typechecker and match compiler give much more informative messages
if System.Control.markabsyn is true.  Unfortunately this requires
(even) more memory.

The debugger (courtesy of Andrew Tolmach) is present in the source, but
does not yet work and is not installed.

The internal representation of first-class continuations is more explicit
about exception-handlers; this will be useful for the new signal-handler
mechanism.

The type-checker is much cleaned up.  User-bound type variables don't appear
in global symbol tables.

Minor (unreported) bugs in the precedence parser and SPARC code generators
are fixed.

---------------------------------------------------------------------------
Standard ML of New Jersey version 0.49, 26 January 1990

New Parser:  The parser is now completely rewritten, using the parser
generator developed by David Tarditi and Andrew Appel.  It's a bit
slower and a bit bigger (though we're working on these problems), but
it generates significantly better error messages and error recovery.
It's also more maintainable.

ML now runs on 68020-based HP workstations running either HP-UX or MORE.

Making sharable images:
There is now a new version of "linkdata", called "clinkdata", that
is relatively machine- and operating-system-independent, but
is much faster than the old "slinkdata".  This will be of interest to
NeXT users, MIPS users, and other users of operating systems where
the "a.out" format is different from Berkeley Unix.  The "makeml"
file now uses "clinkdata" instead of "slinkdata" for such machines.

Bug fixes---many bugs are fixed, including:

2. (L.3):  Mispelled nonnullary constructors in patterns [parser]
8. (L.9):  interactive error recovery
11. (L.12):  poor error messages [parser]
15. (E.12):  Error message
17. (E.25):  Inaccurate line numbers
29. (E.62):  use_string in structure definition
48. printing of identity withtype declarations
63. curried, clausal def of infix function
70. (E.74) constructor shouldn't appear in printed structure signature
71. (E.75) Failure to restore enviroment after exception in "use"
73. strange function definition
77. unparenthesized infix expressions in fun lhs
79. withtype
83. unexpected parsing of erroneous datatype declaration
89. continuation line string escape at beginning of string
90. secondary prompt is not set in multi-line strings and comments.
95. infix declaration interferes with type parsing
100. constructor not printed after open declaration
112. equality of ~0.0 and ~ 0.0
113. empty declarations
117. sharing and equality attributes
134. type checking
136. linkdata problem
145. stale top-level continuations cause type bugs
150. incomplete sharing spec accepted
152. floating point errors (wasn't a bug)
154. import smashing memory (fixed in 0.44a, actually)
156. confusing parser error message
157. nested imports corrupt memory (same as 154)
162. ByteArray subscript exception expected (wasn't a bug)
163. function definition syntax
170.  error in makeml script
201. funny tycon aliasing behavior
202. type error not caught?
204. constructors printed when not accessible
. Runs on NeXT machine (there was a bug in makeml)
. Runs on HP workstation (68020-based)
. exportFn images will never include the compiler, as they sometimes did.

------------------------------------------------------------------------------
Standard ML of New Jersey version 0.44, 4 December 1989

New release:

Starting with this release, the compiler source code is covered by an AT&T
copyright notice, which is included in each source code file.  The file
doc/COPYRIGHT contains the official copyright notice, license, and
disclaimer.  The file doc/release-form contains a release form that our
lawyer would like you to sign if you contribute software or modifications
that are included in the distribution.  Whether you sign it as an
individual or get your institution to sign it is your decision, but it is
undoubtedly quicker and simpler to sign as an individual.  The release form
is not necessary for simple bug fixes.

Mailing list:

There is now a Standard ML mailing list for messages and queries of general
interest to the ML community.  You can join by sending a request to
[e-mail], and you can send a message to the list by mailing
to [e-mail].  This mailing list will be the main vehicle for
distributing announcements about Standard ML of New Jersey.

Modules:

All known major bugs in the module system have been fixed, so please report
any new bugs or old bugs we missed.  The full module syntax from the
Definition, Version 3 is now implemented with minor limitations or
extensions, including let structure expressions and local and open
signature specs (see comments in doc/localspec).  Include specs work
properly once again.

Local and open specs:

David MacQueen has some comments about "local" and "open" specifications
in signatures; see doc/localspec.

Weak type variable syntax:

Standard ML of New Jersey has a more precise system for weak typing
(i.e. typechecking of programs that use semi-polymorphic reference
variables).  Other compilers denote weak type variables with an underscore,
i.e. '_abc, while ours uses an initial integer to denote level of weakness,
i.e. '2abc.  See doc/weak-types for a fuller explanation.  However,
for compatibility:
  The notation for weak type variables using an initial underscore is now
supported for input and output.  A weak type variable of the form '_a
is equivalent to the numeric form '1a.  On output, weak type variables
are printed using an initial integer.  However, if the ref variable
System.Control.weakUnderscore is set to true, then weak type variables
of all levels are printed with an underscore.

Equality types:

Equality types are still broken.  Fixing these is the next order of business.

Import:

Nested imports do not work reliably in this version.

Optimizing compiler:

Hints on making your programs run faster are in doc/optimize.

Miscellaneous:

The SPARC code generator has been completely rewritten by John Reppy.

Bruce Duba continues to make improvements to the CPS code generator.

Andrew Appel is re-writing the parser to use David Tarditi's newest
version of the ML parser generator; this re-write is not complete but
the source files are included (along with the working recursive descent
parser) in src/parse/.

Linkdata:

The "linkdata" program, used for making a sharable version of the ML
compiler by putting all the .mo files into the text segment, did not work
on all operating systems.  There is a more portable, albeit much less
efficient, version of linkdata called "slinkdata".  Look in "src/makeml" to
see how it is used for the NeXT operating system, and you can use it that
way for your operating system too.  (Admittedly, this is very minimal
documentation!)

Bug fixes:

See latest doc/bugs file for remaining bugs.  This has been brought more or
less up to date.  We appreciate your bug reports and hope you will be
patient as we work our way through them.  There is a new version of the
bug report format file (doc/bug.form), including a new "Severity:" field
that you should use to indicate how serious the bug is from your point of
view.  We get a lot of bug reports (which is good!) but we may not assign
the right priority to them without your help.

Version 1 plan:

Our tentative schedule calls for the release of version 1 of the compiler in
mid-January 1990.  There will probably be one more beta release between now
and then.  This is a more or less arbitrary deadline, and we will try to fix
as many bugs as possible before version 1 is released.  Development of the
compiler will continue as usual following this milestone, and major, widely
publicized releases will occur on a more regular and less frequent schedule,
e.g. perhaps three times a year.  Interim developmental versions can be made
available to those who have a special need for them.

------------------------------------------------------------------------------
Standard ML of New Jersey version 0.42, 27 October 1989

Release notes by Andrew Appel, covering changes since version 0.39.

Bug fixes:

Large floating point literals do the right thing now, at least on the Vax.

Duplicate constructor names and field names are again detected.

Printing of records like {1="abc"} works correctly.

Reading 1025 bytes from standard input works.

Large list expressions of the form [(0,0),(0,0),(0,0), ..... (0,0)] no longer
   cause the compiler to blow up.

Previous versions have run on Sun-3s with Mach, this version might work
on Vaxes with Mach.  The next version should run on anything with Mach.

Compile-time processing of functors has been extensively rewritten,
and should be more robust.  There are still some remaining bugs, however,
which should now be easy to iron out.

The Io exception now carries a much more useful string value, containing
all sorts of information.

Other changes since version 0.39 are mostly of interest to implementors.
VALvars and STRvars now have qualids instead of ids, lexer interface
parametrized more cleanly.  Page-faulting is no longer used to detect
end-of-memory on most machines.

---------------------------------------------------------------------------
Standard ML of New Jersey version 0.39, 8 September 1989

This notes overlap with the 0.36 release notes, since 0.36 was not
widely distributed [neither were 0.37 or 0.38].

Release notes by Andrew Appel.

Changes since version 0.33:

1.  Support for Sun-4 (SPARC) thanks to John Reppy at Cornell;
    Encore (NS32032), NeXT (also Mach on other 68020 machines), and
    Sony NEWS (68020-based workstation), thanks to James O'Toole at MIT.

2.  An interpreter for faster compilation (4x) but slower execution (18x).
    Set System.Control.interp := true to enable this mode.  Use the -i
    or -ionly to makeml to set this option as the default.

3.  Delay and Force primitives (meant for internal use only) for research
    in lazy evaluation.

4.  Bug fixes:   reading 2049-byte files works now.  Separate compilation
    shouldn't dump core.  Miscellaneous others.

5.  A code generator generator implemented by Johan Lilius,
    Jari Porra, & Jussi Rintanen of Helsinki University of Technology
    is include in the Standard ML Software Library: see lib/twig.

6.  Various internal efficiency improvements; the CMACHINE signature was
    simplified a bit; the format of generational-gc update lists was changed;
    the CPS optimizer was beefed up.

7.  Separate compilation has been improved.  The compiled version of a
    separately compiled file has the extension ".bin", and internally
    identifies the version of SML-NJ and also the machine type it
    runs on.  The command "head -1 foo.bin" will print this information.

8.  Many functor bugs have been fixed.

9.  An improved version of ML-Yacc by David Tarditi at Princeton is provided,
    more efficient and with a better interface, and with sophisticated syntax
    error recovery.

Forthcoming in future releases:

- Mach support for Vax and other machines.

- Some work has been done on a MacIntosh II port, and we are hoping for
volunteers to continue this work.

- Our MIPS code generator almost works now (thanks to Norman Ramsey at
Princeton).

-----------------------------------------------------------------------------
What's new in SML of NJ Version 0.33, 1 April 1989

1. CPS code generator

This version uses a new CPS (Continuation Passing Style) code
generator.  The CPS code generator differs from the older code
generator in the following ways:

   (i) The code produced is about 50% faster.

   (ii) The compiler generates code about half as quickly (this should
gradually improve with future releases).

   (iii) the new code generator does not use a stack.  This makes it easier
to support experimental features like callcc and multiple processes.
It also makes efficient garbage collection even more critical.

   (iv) The cps code generator tends to build larger intermediate
representations, so tuning of the runtime system becomes more
important.  See the discussion of memory management in doc/INSTALL.


2. The runtime system

The runtime system has been extensively rewritten and cleaned up.  The
amount of assembly code has been reduced (only 220 lines for the Vax,
385 for the Sun), and the system call interface has been simplified.  The
mechanism for initiating garbage collection has been made more robust.
In the m68 version (for Sun 3), exhaustion of free space is detected
by an explicit comparison rather than by trapping a segmentation fault.
This finally eliminates persistent flakiness caused by the way the 68020
recovers from segmentation faults.

LaTeX source for a new paper describing the runtime system can be
found in doc/papers/runtime.  This is still an early draft, but it should
be helpful in understanding internals of the run time system.


3. The pervasive environment

The initial environment has been reorganized to make it possible to
build a system whose pervasives (i.e., built-in bindings) correspond
closely to those described in "The Definition of Standard ML, Version
2" by R. Harper, R. Milner, and M. Tofte (ECS-LFCS-88-62, August 1988,
hereafter referred to as the "Definition").  Note that in our humble
opinion the "standard" environment is somewhat brain-damaged and is
missing many important features (like arrays, bytearrays, etc).  See
the file doc/environ for discussion of specific deficiencies of the
environment described in the Definition and our proposed fixes, some
of which are incorporated in the "New Jersey" environment.

The default initial environment set up by the bootstrapping process is
the richer, and more efficient, New Jersey environment.  However,
loading the source file src/lib/standard.sml defines a structure named
Standard that provides a close approximation to the "standard"
environment.  Opening the structure Standard at the top level replaces
any nonstandard bindings in the New Jersey environment.  The New
Jersey environment is still there in the background, so any New Jersey
bindings not rebound in Standard will still be visible.  In the future
we may provide a mechanism (e.g. a function switchEnv: string -> unit)
for completely replacing the base environment with a different version
specified by a structure.  For example, `switchEnv "Standard"' would
replace the existing base environment with the contents of Standard.

The initial environment also contains:

(1) The signatures ARRAY, BASICIO, BITS, BOOL, BYTEARRAY, GENERAL, IO,
    INTEGER, LIST, REF, STRING, and REAL as defined in src/boot/perv.sig,
    and the signature SYSTEM as defined in src/boot/system.sig

(2) The structures Array : ARRAY, BasicIO : BASICIO, Bits : BITS, etc.
    These contain the New Jersey versions of bindings.

(3) The structure NewJersey, which contains the complete New Jersey initial
    environment except for the signatures in (1) above and the structure
    NewJersey itself.

It follows that even if Standard has been defined and opened, all New Jersey
bindings are available via the structure NewJersey, or alternatively via
the structures Array, IO, etc.

Here are some differences between the New Jersey and Standard environments:

  a.  The functions +, /, *, -, div, mod are an order of magnitude
      slower in Standard than in the New Jersey environment.  This is
      because they are required to raise distinct exceptions (according
      to the Definition), and because the treatment of negative arguments
      of div and mod doesn't match what the hardware provides; that
      complicates their implementation.  The NewJersey functions all raise
      Overflow on results that won't fit in 31 bits (and Div on zero divisor
      for div and mod).

  b.  The functions div and mod return different results.

  c.  input and output are curried in NewJersey (and in the IO structure),
      but not in Standard.

  d.  The New Jersey environment has many more functions in it, as described
      in the appendix of our reference manual or the signatures in the files
      src/boot/perv.sig and src/boot/system.sig.

The New Jersey environment has changed slightly from previous releases,
mostly to make the it more compatible with the Definition [IMPORTANT --
THESE CHANGES MAY BREAK SOME PROGRAMS]:

  a.  The exception Io_failure has been renamed Io for consistency
      with the Definition.

  b.  The exception Float has been renamed Real.  Float is still defined
      as a synonym for Real.

  c.  The identifier "length" is no longer overloaded: use "size" or
      "String.size" for string lengths, "length" or "List.length" for
      list lengths, and "Array.length" for array lengths.

  d.  The functions "cd" and "system" are now components of the
      System structure.

  e.  Various components of the System structure have been moved
      into the System.Unsafe substructure, and are not recommended for
      casual use.

  f.  The print functions (Integer.print, Real.print, String.print,
      and the overloaded print), now return unit rather than their
      argument.  This is because we found that in our code virtually
      every call of print was followed by "; ()".

We plan to provide a definition of the NewJersey structure in terms of
the "standard" environment (analogous to the definition of Standard in
lib/src/standard.sml).  This structure would enable any Standard ML
system to run programs based on the New Jersey environment.  Such
programs should not reference the System structure, of course.

4. Command line arguments and Shell environment

System.argv : unit -> string list
System.environ : unit -> string list

are new functions that return the list of command line arguments and
the Unix shell environment, respectively.

5. First-class continuations: callcc, throw, and cont (experimental)

These are new experimental primitives to allow one to capture and use
"first-class continuations".  See the file doc/callcc for
documentation of these new facilities.

6. Separate compilation (experimental)

We have integrated code written by Nick Rothwell and Mads Tofte of
Edinburgh that provides a preliminary, experimental form of secure (type
checked) separate compilation.  There is a special declaration form:

   import "filename"

where "filename" is a string literal designating either a source file
filename.sml or a binary file filename.bin.  If only the source file
exists in the current directory, then it is compiled and the binary
version is created.  If the binary version exists, it is loaded
instead of the source file.

As a consequence of adding this new facility, the identifier "import"
has become a reserved word.  This may cause incompatibilities with
existing code.

7. mlyacc

The new directory src/lib/mlyacc contains a yacc-like parser generator
written in ML, with documentation.  The parser generator is used much
like the Unix yacc utility, and the grammar specification language is
essentially that of yacc.  The parser generator was written by David
Tarditi of Princeton, based on an earlier effort by Nick Rothwell.
Other, more sophisticated, interfaces to the parser generator will
probably be provided in future releases.  As before, the directory
src/lib/lexgen contains a lexical analyzer generator.

8. Fixes

A number of things that have been broken are now fixed.  This includes
the garbage collector for the Sun 3, floating point operations on the
Sun 3, exportFn, sqrt, and execute.  Unfortunately, many old bugs
remain and the error messages are just as bad as ever.  We expect the
next release to fix many of these problems.  Bug reports are welcome as
ever, as are bug fixes.

9. Things to come

John Reppy has ported SML of NJ to the Sun 4 (SPARC) architecture and
his code generator will be included in the next release.  A port to
the MIPS architecture (DECstation 3100 under Ultrix) is in the works
at Princeton, and a NeXT port is likely.  A port to the Mac II under
the native Mac OS may also appear soon.

We are working on a new licensing scheme similar to that used by the
Free Software Foundation.  We hope to have this approved within three
months, and we will keep you informed of new developments.

------------------------------------------------------------------------------
New features of SML of NJ Version 0.24 (November 22, 1988)

1. Profiler

A call-count and statistical profiler has been implemented.  See
operating instructions in the README file, and the paper provided in
src/doc/papers/profiling.


2. Runtime reorganization

The runtime system has been reorganized to reduce the need for assembly
language and provide a standard interface for Unix system calls and
C code.  It should become possible to add special purpose C code to
the runtime system, for instance to provide an X windows interface.
Many of the assembly language functions have been replaced by more
portible C implementations and uses of the system call interface.
See src/doc/VERSION.24 for some more details.


3. Memory Management tuning

The variable

  System.Control.Runtime.ratio : int ref

can be used to control the garbage collection behavior to some extent,
in conjunction with the Unix limit variable (in the csh).  See the
discussion in README.


4. Simple gnu emacs sml mode

A simple gnu emacs sml mode was contributed by Mitch Wand.  It can be
found in src/lib/sml.el.  If you have a better mode or make improvements
on this version, please send them in to [e-mail] for
inclusion in future releases.
--------------------------------------------------------------------------
New features of SML of NJ Version 0.22 (October 10, 1988)

This file describes the most notable changes since version 0.20.  (Version 0.21
was a local version that was not distributed.)


1. Bugs

A few bugs have been fixed; exportFn works again; the system runs under the
latest version (4.0) of Sun Unix on a Sun-3.  See src/doc/bugs for the
remaining known bugs.  The next release with many more bug fixes will
probably follow fairly shortly.


2. Sharable text segments

We now have an option to run sml with the compiler read-only and sharable
(in the Unix text segment).  This should help on systems where several
people are running sml at once, and also improves garbage-collector performance.
See src/doc/INSTALL for more info.


3. CPS code generator

We are including the source code for the new cps code generator with
this release for those who would like an early look at it.  This code
generator is still under development and works only on Vaxes at this
point.


4. Installation

The maker script for building the interactive image has been reorganized
and new scripts maker.batch and maker.run have been added to simplify
making batch systems and compiling the runtime system.  See src/doc/INSTALL
and src/doc/BATCHINSTALL for details.


5. Lexer generator

The directory src/lib is a new directory for contributed software.
The programs included here do not come under the terms of the AT&T
license.  The first contributed software is a lexical analyzer
generator similar to the Unix lex utility.  It is in src/lib/lexgen.
lexgen has been used to generate a new lexical analyzer for the
compiler.  The specification is in src/lex/ml.lex.


----------------------------------------------------------------------------
New features of SML of NJ Version 0.20

This file describes the most notable changes since version 0.18.  (Version 0.19
was a local version that was not distributed.)

1. Bugs

Quite a few bugs have been fixed, mostly relating to type checking and modules.
See src/doc/bugs for the remaining known bugs.


2. Reference types

The typing of references and arrays is less restrictive.  For
instance, the following is now permitted, whereas it used to cause an
error message:

   let val r = ref [] in r := [1]; !r end;

Thus locally declared reference variables like r in this example do not
need to be explicitly constrained to have a monotype.


3. Equality types

Equality types are now implemented.  Equality types are those
"hereditarily concrete" types whose values admit structural equality.
The implementation of equality types involves the new signature
specification keyword "eqtype" indicating that the specified type
constructor admits equality, and special equality type variables
starting with double single quotes (e.g. ''a) that are restricted to
range over equality types.

An equality type is one containing only type constructors that "support
equality".  The following type constructors support equality:

   int, string, real

   any datatype whose constuctor argument types are equality types
   (disregarding parameter type variables)

   record type constructors

   type constructors from functor parameters that are specified as eqtypes

In addition, any reference or array type is an equality type.

Abstract type constructors, "->", and exn do not support equality.


4. Include specifications in signatures

Include specifications allow one to include the specifications of a previously
defined signature in a new signature.  The syntax is

   include SIG

where SIG is the name of a signature.  For example, given the declaration

   signature AA =
   sig
     type t
     val x : t
   end

the declaration

   signature BB =
   sig
     include AA
     val y : t -> int
   end

is equivalent to

   signature BB =
   sig
     type t
     val x : t
     val y : t -> int
   end


5. Free identifiers in signatures and structures

Structure definitions can now contain free identifiers of any sort
(values, constructors, exceptions, types), not just free signatures,
structures and functors.  Signature definitions can contain free
structure and type identifiers, as well as free signature identifiers.


6. Printing of signatures and structures

Signatures defined at top level are printed.  Structures defined at
top level have their signatures printed (currently in full -- in the
future only the name of the signature will be printed if it has one).
Printing of signatures can be turned off by setting the flag
System.Control.Print.signatures to false.


7. Memory management improvements

The runtime system manages memory better.  The system automatically
resizes the heap on startup and during collections, allowing the
system to perform more gracefully on systems with limited memory.

The behavior and type of the flag controlling gc messages has changed:

  System.Control.Runtime.gcmessages: int ref
    when 0, no messages are printed
    when 1, only major collections are reported
    when 2, major collections and heap resizings are reported
    when 3, minor and major collections and heap resizings are reported