ocaml/Changes

Objective Caml 3.03:
--------------------

Language:
- Switched the default behaviour to labels mode (labels are compulsory),
  but allows omitting labels when a function application is complete.
  -nolabels mode is available but deprecated for programming.
  (See also scrapelabels and addlabels tools lower)
- Removed all labels in the standard libraries, except labltk.
  Labelized versions are kept for ArrayLabels, ListLabels, StringLabels
  and UnixLabels. "open StdLabels" gives access to the first three.
- Extended polymorphic variant type syntax, allowing union types and
  row abbreviations for both sub- and super-types. #t deprecated in types.

Type-checker:
- Fixed obscure bug in module typing causing the type-checker to loop
  on signatures of the form
        module type M
        module A: sig module type T = sig module T: M end end
        module B: A.T
- Improved efficiency of module type-checking via lazy computation of
  certain signature summary information.

Byte-code compiler:
- Protect against VM stack overflow caused by module initialization code
  with many local variables.
- Support for dynamic loading of the C part of mixed Caml/C libraries.

Native-code compiler:
- Attempt to recover gracefully from system stack overflow.  Currently
  works on x86 under Linux and BSD.
- Alpha: work around "as" bug in Tru64 5.1.

Toplevel environment:
- Revised printing of inferred types and evaluation results
  so that an external printer (e.g. Camlp4's) can be hooked in.

Tools:
- New tool ocamlmklib to help build mixed Caml/C libraries.
- New tool scrapelabels and addlabels, to either remove (non-optional)
  labels in interfaces, or automatically add them in the definitions.
  They provide easy transition from classic mode ocaml 3.02 sources,
  depending on whether you want to keep labels or not.
- ocamldep: added -pp option to handle preprocessed source files.

Run-time system:
- Support for dynamic loading of the C part of mixed Caml/C libraries.
  Currently works under Linux, FreeBSD, Windows, Tru64, Solaris and Irix.
- Implemented registration of global C roots with a skip list,
  runs much faster when there are many global C roots.
- Autoconfiguration script: fixed wrong detection of Mac OS X; problem
  with the Sparc, gcc 3.0, and float alignment fixed.

Other libraries:
- All libraries revised to allow dynamic loading of the C part.
- Graphics under X Windows: revised event handling, should no longer lose
    mouse events between two calls to wait_next_event(); wait_next_event()
    now interruptible by signals.

Windows port:
- Fixed broken Unix.{get,set}sockopt*

Objective Caml 3.02:
--------------------

Both compilers:
- Fixed embarrassing bug in pattern-matching compilation
  (affected or-patterns containing variable bindings).
- More optimizations in pattern-matching compilation.

Byte-code compiler:
- Protect against VM stack overflow caused by functions with many local
  variables.

Native-code compiler:
- Removed re-sharing of string literals, causes too many surprises with 
  in-place string modifications.
- Corrected wrong compilation of toplevel "include" statements.
- Fixed bug in runtime function "callbackN_exn".
- Signal handlers receive the conventional signal number as argument
  instead of the system signal number (same behavior as with the
  bytecode compiler).
- ARM port: fixed issue with immediate operand overflow in large functions.

Toplevel environment:
- User-definer printers (for #install_printer) now receive as first argument
  the pretty-printer formatter where to print their second argument.
  Old printers (with only one argument) still supported for backward
  compatibility.

Standard library:
- Module Hashtbl: added Hashtbl.fold.

Other libraries:
- Dynlink: better error reporting in add_interfaces for missing .cmi files.
- Graphics: added more drawing functions (multiple points, polygons,
    multiple lines, splines).
- Bytecode threads: the module Unix is now thread-safe, ThreadUnix is
    deprecated.  Unix.exec* now resets standard descriptors to blocking mode.
- Native threads: fixed a context-switch-during-GC problem causing
    certain C runtime functions to fail, most notably input_value.
- Unix.inet_addr_of_string: call inet_aton() when available so as to
    handle correctly the address 255.255.255.255.
- Unix: added more getsockopt and setsockopt functions to get/set
    options that have values other than booleans.
- Num: added documentation for the Big_int module.

Tools:
- ocamldep: fixed wrong dependency issue with nested modules.

Run-time system:
- Removed floating-point error at start-up on some non-IEEE platforms
  (e.g. FreeBSD prior to 4.0R).
- Stack backtrace mechanism now works for threads that terminate on
  an uncaught exception.

Auto-configuration:
- Updated config.guess and config.sub scripts, should recognize a greater
  number of recent platform.

Windows port:
- Fixed broken Unix.waitpid.  Unix.file_descr can now be compared or hashed.
- Toplevel application: issue with spaces in name of stdlib directory fixed.

MacOS 9 port:
- Removed the last traces of support for 68k


Objective Caml 3.01:
--------------------

New language features:
- Variables are allowed in "or" patterns, e.g.
     match l with [t] | [_;t] -> ... t ...
- "include <structure expression>" to re-export all components of a
  structure inside another structure.
- Variance annotation on parameters of type declarations, e.g.
    type (+'a,-'b,'c) t (covariant in 'a, contravariant in 'b, invariant in 'c)

New ports:
- Intel IA64/Itanium under Linux (including the native-code compiler).
- Cygwin under MS Windows.  This port is an alternative to the earlier
  Windows port of OCaml, which relied on MS compilers; the Cygwin
  Windows port does not need MS Visual C++ nor MASM, runs faster
  in bytecode, and has a better implementation of the Unix library, 
  but currently lacks threads and COM component support.

Type-checking:
- Relaxed "monomorphic restriction" on type constructors in a 
  mutually-recursive type definition, e.g. the following is again allowed
    type u = C of int t | D of string t and 'a t = ...
- Fixed name-capture bug in "include SIG" and "SIG with ..." constructs.
- Improved implicit subtypes built by (... :> ty), closer to intuition.
- Several bug fixes in type-checking of variants.
- Typing of polymorphic variants is more restrictive:
   do not allow conjunctive types inside the same pattern matching.
   a type has either an upper bound, or all its tags are in the lower bound.
  This may break some programs (this breaks lablgl-0.94).

Both compilers:
- Revised compilation of pattern matching.
- Option -I +<subdir> to search a subdirectory <subdir> of the standard
  library directory (i.e. write "ocamlc -I +labltk" instead of 
  "ocamlc -I /usr/local/lib/ocaml/labltk").
- Option -warn-error to turn warnings into errors.
- Option -where to print the location of the standard library directory.
- Assertions are now type-checked even if the -noassert option is given,
  thus -noassert can no longe change the types of modules.

Bytecode compiler and bytecode interpreter:
- Print stack backtrace when a program aborts due to an uncaught exception
  (requires compilation with -g and running with ocamlrun -b or
   OCAMLRUNPARAM="b=1").

Native-code compiler:
- Better unboxing optimizations on the int32, int64, and nativeint types.
- Tail recursion preserved for functions having more parameters than
  available registers (but tail calls to other functions are still
  turned off if parameters do not fit entirely in registers).
- Fixed name-capture bug in function inlining.
- Improved spilling/reloading strategy for conditionals.
- IA32, Alpha: better alignment of branch targets.
- Removed spurious dependency on the -lcurses library.

Toplevel environment:
- Revised handling of top-level value definitions, allows reclaimation
  of definitions that are shadowed by later definitions with the same names.
  (E.g. "let x = <big list>;; let x = 1;;" allows <big list> to be reclaimed.)
- Revised the tracing facility so that for standard library functions,
  only calls from user code are traced, not calls from the system.
- Added a "*" prompt when within a comment.

Runtime system:
- Fixed portability issue on bcopy() vs memmove(), affecting Linux RedHat 7.0
  in particular.
- Structural comparisons (=, <>, <, <=, >, >=, compare) reimplemented
  so as to avoid overflowing the C stack.
- Input/output functions: arrange so that reads and writes on closed
  in_channel or out_channel raise Sys_error immediately.

Standard library:
- Module Gc: changed some counters to float in order to avoid overflow;
    added alarms
- Module Hashtbl: added Hashtbl.replace.
- Module Int64: added bits_of_float, float_of_bits (access to IEEE 754
    representation of floats).
- Module List:  List.partition now tail-rec; 
    improved memory behavior of List.stable_sort.
- Module Nativeint: added Nativeint.size (number of bits in a nativeint).
- Module Obj: fixed incorrect resizing of float arrays in Obj.resize.
- Module Pervasives: added float constants "infinity", "neg_infinity", "nan";
    added a "classify_float" function to test a float for NaN, infinity, etc.
- Pervasives.input_value: fixed bug affecting shared custom objects.
- Pervasives.output_value: fixed size bug affecting "int64" values.
- Pervasives.int_of_string, {Int32,Int64,Nativeint}.of_string:
  fixed bug causing bad digits to be accepted without error.
- Module Random: added get_state and set_state to checkpoint the generator.
- Module Sys: signal handling functions are passed the system-independent
  signal number rather than the raw system signal number whenever possible.
- Module Weak: added Weak.get_copy.

Other libraries:
- Bigarray: added Bigarray.reshape to take a view of the elements of a
  bigarray with different dimensions or number of dimensions;
  fixed bug causing "get" operations to be unavailable in custom
  toplevels including Bigarray.
- Dynlink: raise an error instead of crashing when the loaded module
  refers to the not-yet-initialized module performing a dynlink operation.
- Bytecode threads: added a thread-safe version of the Marshal module;
    fixed a rare GC bug in the thread scheduler.
- POSIX threads: fixed compilation problem with threads.cmxa.
- Both thread libraries: better tail-recursion in Event.sync.
- Num library: fixed bug in square roots (Nat.sqrt_nat, Big_int.sqrt_big_int).

Tools:
- ocamldep: fixed missing dependencies on labels of record patterns and
    record construction operations

Win32 port:
- Unix.waitpid now implements the WNOHANG option.

Mac OS ports:
- Mac OS X public beta is supported.
- Int64.format works on Mac OS 8/9.


Objective Caml 3.00:
--------------------

Language:
- OCaml/OLabl merger:
  * Support for labeled and optional arguments for functions and classes.
  * Support for variant types (sum types compared by structure).
  See tutorial (chapter 2 of the OCaml manual) for more information.
- Syntactic change: "?" in stream error handlers changed to "??".
- Added exception renaming in structures (exception E = F).
- (OCaml 2.99/OLabl users only) Label syntax changed to preserve
  backward compatibility with 2.0x (labeled function application
  is f ~lbl:arg instead of f lbl:arg).  A tool is provided to help
  convert labelized programs to OCaml 3.00.

Both compilers:
- Option -labels to select commuting label mode (labels are mandatory,
  but labeled arguments can be passed in a different order than in
  the definition of the function; in default mode, labels may be omitted,
  but argument reordering is only allowed for optional arguments).
- Libraries (.cma and .cmxa files) now "remember" C libraries given
  at library construction time, and add them back at link time.
  Allows linking with e.g. just unix.cma instead of
  unix.cma -custom -cclib -lunix
- Revised printing of error messages, now use Format.fprintf; no visible
  difference for users, but could facilitate internationalization later.
- Fixed bug in unboxing of records containing only floats.
- Fixed typing bug involving applicative functors as components of modules.
- Better error message for inconsistencies between compiled interfaces.

Bytecode compiler:
- New "modular" format for bytecode executables; no visible differences
  for users, but will facilitate further extensions later.
- Fixed problems in signal handling.

Native-code compiler:
- Profiling support on x86 under FreeBSD
- Open-coding and unboxing optimizations for the new integer types
  int32, int64, nativeint, and for bigarrays.
- Fixed instruction selection bug with "raise" appearing in arguments
  of strict operators, e.g. "1 + raise E".
- Better error message when linking incomplete/incorrectly ordered set
  of .cmx files.
- Optimized scanning of global roots during GC, can reduce total running
  time by up to 8% on GC-intensive programs.

Interactive toplevel:
- Better printing of exceptions, including arguments, when possible.
- Fixed rare GC bug occurring during interpretation of scripts.
- Added consistency checks between interfaces and implementations
  during #load.

Run-time system:
- Added support for "custom" heap blocks (heap blocks carrying
  C functions for finalization, comparison, hashing, serialization
  and deserialization).
- Support for finalisation functions written in Caml.

Standard library:
- New modules Int32, Int64, Nativeint for 32-bit, 64-bit and
  platform-native integers
- Module Array: added Array.sort, Array.stable_sort.
- Module Gc: added Gc.finalise to attach Caml finalisation functions to
  arbitrary heap-allocated data.
- Module Hashtbl: do not bomb when resizing very large table.
- Module Lazy: raise Lazy.Undefined when a lazy evaluation needs itself.
- Module List: added List.sort, List.stable_sort; fixed bug in List.rev_map2.
- Module Map: added mapi (iteration with key and data).
- Module Set: added iterators for_all, exists, filter, partition.
- Module Sort: still here but deprecated in favor of new sorting functions
  in Array and List.
- Module Stack: added Stack.top
- Module String: fixed boundary condition on String.rindex_from
- Added labels on function arguments where appropriate.

New libraries and tools:
- ocamlbrowser: graphical browser for OCaml sources and compiled interfaces,
  supports cross-referencing, editing, running the toplevel.
- LablTK: GUI toolkit based on TK, using labeled and optional arguments,
  easier to use than CamlTK.
- Bigarray: large, multi-dimensional numerical arrays, facilitate
  interfacing with C/Fortran numerical code, efficient support for
  advanced array operations such as slicing and memory-mapping of files.

Other libraries:
- Bytecode threads: timer-based preemption was broken, works back again;
  fixed bug in Pervasives.input_line; exported Thread.yield.
- System threads: several GC / reentrancy bugs fixed in buffered I/O
  and Unix I/O; revised Thread.join implementation for strict POSIX
  conformance; exported Thread.yield.
- Graphics: added support for double buffering; added, current_x, current_y,
  rmoveto, rlineto, and draw_rect.
- Num: fixed bug in Num.float_of_num.
- Str: worked around potential symbol conflicts with C standard library.
- Dbm: fixed bug with Dbm.iter on empty database.

New or updated ports:
- Alpha/Digital Unix: lifted 256M limitation on total memory space 
  induced by -taso
- Port to AIX 4.3 on PowerPC
- Port to HPUX 10 on HPPA
- Deprecated 680x0 / SunOS port

Macintosh port:
- Implemented the Unix and Thread libraries.
- The toplevel application does not work on 68k Macintoshes; maybe
  later if there's a demand.
- Added a new tool, ocamlmkappli, to build an application from a
  program written in O'Caml.


Objective Caml 2.04:
--------------------

- C interface: corrected inconsistent change in the CAMLparam* macros.
- Fixed internal error in ocamlc -g.
- Fixed type-checking of "S with ...", where S is a module type name
  abbreviating another module type name.
- ocamldep: fixed stdout/stderr mismatch after failing on one file.
- Random.self_init more random.
- Windows port:
  - Toplevel application: fixed spurious crash on exit.
  - Native-code compiler: fixed bug in assembling certain
    floating-point constants (masm doesn't grok 2e5, wants 2.0e5).

Objective Caml 2.03:
--------------------

New ports:
- Ported to BeOS / Intel x86 (bytecode and native-code).
- BSD / Intel x86 port now supports both a.out and ELF binary formats.
- Added support for {Net,Open}BSD / Alpha.
- Revamped Rhapsody port, now works on MacOS X server.

Syntax:
- Warning for "(*)" and "*)" outside comment.
- Removed "#line LINENO", too ambiguous with a method invocation;
  the equivalent "# LINENO" is still supported.

Typing:
- When an incomplete pattern-matching is detected, report also a 
  value or value template that is not covered by the cases of 
  the pattern-matching.
- Several bugs in class type matching and in type error reporting fixed.
- Added an option -rectypes to support general recursive types,
  not just those involving object types.

Bytecode compiler:
- Minor cleanups in the bytecode emitter.
- Do not remove "let x = y" bindings in -g mode; makes it easier to
  debug the code.

Native-code compiler:
- Fixed bug in grouping of allocations performed in the same basic block.
- Fixed bug in constant propagation involving expressions containing
  side-effects.
- Fixed incorrect code generation for "for" loops whose upper bound is
  a reference assigned inside the loop.
- MIPS code generator: work around a bug in the IRIX 6 assembler.

Toplevel:
- Fixed incorrect redirection of standard formatter to stderr
  while executing toplevel scripts.

Standard library:
- Added List.rev_map, List.rev_map2.
- Documentation of List functions now says which functions are
  tail-rec, and how much stack space is needed for non-tailrec functions.
- Wrong type for Printf.bprintf fixed.
- Fixed weird behavior of Printf.sprintf and Printf.bprintf in case of
  partial applications.
- Added Random.self_init, which initializes the PRNG from the system date.
- Sort.array: serious bugs fixed.
- Stream.count: fixed incorrect behavior with ocamlopt.

Run-time system and external interface:
- Fixed weird behavior of signal handlers w.r.t. signal masks and exceptions
  raised from the signal handler.
- Fixed bug in the callback*_exn() functions.

Debugger:
- Fixed wrong printing of float record fields and elements of float arrays.
- Supports identifiers starting with '_'.

Profiler:
- Handles .mli files, so ocamlcp can be used to replace ocamlc (e.g. in a
  makefile).
- Now works on programs that use stream expressions and stream parsers.

Other libraries:
- Graphics: under X11, treat all mouse buttons equally; fixed problem
  with current font reverting to the default font when the graphics
  window is resized.
- Str: fixed reentrancy bugs in Str.replace and Str.full_split.
- Bytecode threads: set standard I/O descriptors to non-blocking mode.
- OS threads: revised implementation of Thread.wait_signal.
- All threads: added Event.wrap_abort, Event.choose [].
- Unix.localtime, Unix.gmtime: check for errors.
- Unix.create_process: now supports arbitrary redirections of std descriptors.
- Added Unix.open_process_full.
- Implemented Unix.chmod under Windows.
- Big_int.square_big_int now gives the proper sign to its result.

Others:
- ocamldep: don't stop at first error, skip to next file.
- Emacs mode: updated with Garrigue and Zimmerman's snapshot of 1999/10/18.
- configure script: added -prefix option.
- Windows toplevel application: fixed problem with graphics library
  not loading properly.


Objective Caml 2.02:
--------------------

* Type system:
  - Check that all components of a signature have unique names.
  - Fixed bug in signature matching involving a type component and
    a module component, both sharing an abstract type.
  - Bug involving recursive classes constrained by a class type fixed.
  - Fixed bugs in printing class types and in printing unification errors.

* Compilation:
  - Changed compilation scheme for "{r with lbl = e}" when r has many fields
    so as to avoid code size explosion.

* Native-code compiler:
  - Better constant propagation in boolean expressions and in conditionals.
  - Removal of unused arguments during function inlining.
  - Eliminated redundant tagging/untagging in bit shifts.
  - Static allocation of closures for functions without free variables,
    reduces the size of initialization code.
  - Revised compilation scheme for definitions at top level of compilation
    units, so that top level functions have no free variables.
  - Coalesced multiple allocations of heap blocks inside one expression
    (e.g. x :: y :: z allocates the two conses in one step).
  - Ix86: better handling of large integer constants in instruction selection.
  - MIPS: fixed wrong asm generated for String.length "literal".

* Standard library:
  - Added the "ignore" primitive function, which just throws away its
    argument and returns "()".  It allows to write
    "ignore(f x); y" if "f x" doesn't have type unit and you don't
    want the warning caused by "f x; y".
  - Added the "Buffer" module (extensible string buffers).
  - Module Format: added formatting to buffers and to strings.
  - Added "mem" functions (membership test) to Hashtbl and Map.
  - Module List: added find, filter, partition.
    Renamed remove and removeq to remove_assoc and remove_assq.
  - Module Marshal: fixed bug in marshaling functions when passed functional
    values defined by mutual recursion with other functions.
  - Module Printf: added Printf.bprintf (print to extensible buffer);
    added %i format as synonymous for %d (as per the docs).
  - Module Sort: added Sort.array (Quicksort).

* Runtime system:
  - New callback functions for callbacks with arbitrary many arguments
    and for catching Caml exceptions escaping from a callback.

* The ocamldep dependency generator: now performs full parsing of the
    sources, taking into account the scope of module bindings.

* The ocamlyacc parser generator: fixed sentinel error causing wrong
    tables to be generated in some cases.

* The str library:
  - Added split_delim, full_split as variants of split that control
    more precisely what happens to delimiters.
  - Added replace_matched for separate matching and replacement operations.

* The graphics library:
  - Bypass color lookup for 16 bpp and 32 bpp direct-color displays.
  - Larger color cache.

* The thread library:
  - Bytecode threads: more clever use of non-blocking I/O, makes I/O
    operations faster.
  - POSIX threads: gcc-ism removed, should now compile on any ANSI C compiler.
  - Both: avoid memory leak in the Event module when a communication
    offer is never selected.

* The Unix library:
  - Fixed inversion of ctime and mtime in Unix.stat, Unix.fstat, Unix.lstat.
  - Unix.establish_connection: properly reclaim socket if connect fails.

* The DBM library: no longer crashes when calling Dbm.close twice.

* Emacs mode:
  - Updated with Garrigue and Zimmerman's latest version.
  - Now include an "ocamltags" script for using etags on OCaml sources.

* Win32 port:
  - Fixed end-of-line bug in ocamlcp causing problems with generated sources.


Objective Caml 2.01:
--------------------

* Typing:
  - Added warning for expressions of the form "a; b" where a does not have
    type "unit"; catches silly mistake such as
    "record.lbl = newval; ..." instead of "record.lbl <- newval; ...".
  - Typing bug in "let module" fixed.

* Compilation:
  - Fixed bug in compilation of recursive and mutually recursive classes.
  - Option -w to turn specific warnings on/off.
  - Option -cc to choose the C compiler used with ocamlc -custom and ocamlopt.

* Bytecode compiler and bytecode interpreter:
  - Intel x86: removed asm declaration causing "fixed or forbidden register
    spilled" error with egcs and gcc 2.8 (but not with gcc 2.7, go figure).
  - Revised handling of debugging information, allows faster linking with -g.

* Native-code compiler:
  - Fixed bugs in integer constant propagation.
  - Out-of-bound accesses in array and strings now raise an Invalid_argument
    exception (like the bytecode system) instead of stopping the program.
  - Corrected scheduling of bound checks.
  - Port to the StrongARM under Linux (e.g. Corel Netwinder).
  - I386: fixed bug in profiled code (ocamlopt -p).
  - Mips: switched to -n32 model under IRIX; dropped the Ultrix port.
  - Sparc: simplified the addressing modes, allows for better scheduling.
  - Fixed calling convention bug for Pervasives.modf.

* Toplevel:
  - #trace works again.
  - ocamlmktop: use matching ocamlc, not any ocamlc from the search path.

* Memory management:
  - Fixed bug in heap expansion that could cause the GC to loop.

* C interface:
  - New macros CAMLparam... and CAMLlocal... to simplify the handling
    of local roots in C code.
  - Simplified procedure for allocating and filling Caml blocks from C.
  - Declaration of string_length in <caml/mlvalues.h>.

* Standard library:
  - Module Format: added {get,set}_all_formatter_output_functions,
    formatter_of_out_channel, and the control sequence @<n> in printf.
  - Module List: added mem_assoc, mem_assq, remove, removeq.
  - Module Pervasives: added float_of_int (synonymous for float),
    int_of_float (truncate), int_of_char (Char.code), char_of_int (Char.chr),
    bool_of_string.
  - Module String: added contains, contains_from, rcontains_from.

* Unix library:
  - Unix.lockf: added F_RLOCK, F_TRLOCK; use POSIX locks whenever available.
  - Unix.tc{get,set}attr: added non-standard speeds 57600, 115200, 230400.
  - Unix.chroot: added.

* Threads:
  - Bytecode threads: improved speed of I/O scheduling.
  - Native threads: fixed a bug involving signals and exceptions
    generated from C.

* The "str" library:
  - Added Str.string_partial_match.
  - Bumped size of internal stack.

* ocamlyacc: emit correct '# lineno' directive for prelude part of .mly file.

* Emacs editing mode: updated with Jacques Garrigue's newest code.

* Windows port:
  - Added support for the "-cclib -lfoo" option (instead of
     -cclib /full/path/libfoo.lib as before).
  - Threads: fixed a bug at initialization time.

* Macintosh port: source code for Macintosh application merged in.


Objective Caml 2.00:
--------------------

* Language:
  - New class language.  See http://caml.inria.fr/ocaml/refman/
    for a tutorial (chapter 2) and for the reference manual (section 4.9).
  - Local module definitions "let module X = <module-expr> in <expr>".
  - Record copying with update "{r with lbl1 = expr1; ...}".
  - Array patterns "[|pat1; ...;patN|]" in pattern-matchings.
  - New reserved keywords: "object", "initializer".
  - No longer reserved: "closed", "protected".

* Bytecode compiler:
  - Use the same compact memory representations for float arrays, float
    records and recursive closures as the native-code compiler.
  - More type-dependent optimizations.
  - Added the -use_runtime and -make_runtime flags to build separately
    and reuse afterwards custom runtime systems
    (inspired by Fabrice Le Fessant's patch).

* Native-code compiler:
  - Cross-module constant propagation of integer constants.
  - More type-dependent optimizations.
  - More compact code generated for "let rec" over data structures.
  - Better code generated for "for" loops (test at bottom of code).
  - More aggressive scheduling of stores.
  - Added -p option for time profiling with gprof
    (fully supported on Intel x86/Linux and Alpha/Digital Unix only)
    (inspired by Aleksey Nogin's patch).
  - A case of bad spilling with high register pressure fixed.
  - Fixed GC bug when GC called from C without active Caml code.
  - Alpha: $gp handling revised to follow Alpha's standard conventions,
    allow running "atom" and "pixie" on ocamlopt-generated binaries.
  - Intel x86: use movzbl and movsbl systematically to load 8-bit and 16-bit
    quantities, no more hacks with partial registers (better for the
    Pentium Pro, worse for the Pentium).
  - PowerPC: more aggressive scheduling of return address reloading.
  - Sparc: scheduling bug related to register pairs fixed.

* Runtime system:
  - Better printing of uncaught exceptions (print a fully qualified
    name whenever possible).

* New ports:
  - Cray T3E (bytecode only) (in collaboration with CEA).
  - PowerMac under Rhapsody.
  - SparcStations under Linux.

* Standard library:
  - Added set_binary_mode_in and set_binary_mode_out in Pervasives
    to toggle open channels between text and binary modes.
  - output_value and input_value check that the given channel is in
    binary mode.
  - input_value no longer fails on very large marshalled data (> 16 Mbytes).
  - Module Arg: added option Rest.
  - Module Filename: temp_file no longer loops if temp dir doesn't exist.
  - Module List: added rev_append (tail-rec alternative to @).
  - Module Set: tell the truth about "elements" returning a sorted list;
    added min_elt, max_elt, singleton.
  - Module Sys: added Sys.time for simple measuring of CPU time.

* ocamllex:
  - Check for overflow when generating the tables for the automaton.
  - Error messages in generated .ml file now point to .mll source.
  - Added "let <id> = <regexp>" to name regular expressions
    (inspired by Christian Lindig's patch).

* ocamlyacc:
  - Better error recovery in presence of EOF tokens.
  - Error messages in generated .ml file now point to .mly source.
  - Generated .ml file now type-safe even without the generated .mli file.

* The Unix library:
  - Use float instead of int to represent Unix times (number of seconds
    from the epoch).  This fixes a year 2005 problem on 32-bit platforms.
    Functions affected: stat, lstat, fstat, time, gmtime, localtime,
    mktime, utimes.
  - Added putenv.
  - Better handling of "unknown" error codes (EUNKNOWNERR).
  - Fixed endianness bug in getservbyport.
  - win32unix (the Win32 implementation of the Unix library) now has
    the same interface as the unix implementation, this allows exchange
    of compiled .cmo and .cmi files between Unix and Win32.

* The thread libraries:
  - Bytecode threads: bug with escaping exceptions fixed.
  - System threads (POSIX, Win32): malloc/free bug fixed; signal bug fixed.
  - Both: added Thread.wait_signal to wait synchronously for signals.

* The graph library: bigger color cache.

* The str library: added Str.quote, Str.regexp_string,
  Str.regexp_string_case_fold.

* Emacs mode:
  - Fixed bug with paragraph fill.
  - Fixed bug with next-error under Emacs 20.


Objective Caml 1.07:
--------------------

* Native-code compiler:
  - Revised interface between generated code and GC, fixes serious GC
    problems with signals and native threads.
  - Added "-thread" option for compatibility with ocamlc.

* Debugger: correctly print instance variables of objects.

* Run-time system: ported to OpenBSD.

* Standard library: fixed wrong interface for Marshal.to_buffer and
  Obj.unmarshal.

* Num library: added Intel x86 optimized asm code (courtesy of
  Bernard Serpette).

* Thread libraries:
  - Native threads: fixed GC bugs and installation procedure.
  - Bytecode threads: fixed problem with "Marshal" module.
  - Both: added Event.always.

* MS Windows port: better handling of long command lines in Sys.command

Objective Caml 1.06:
--------------------

* Language:
  - Added two new keywords: "assert" (check assertion) and "lazy"
    (delay evaluation).
  - Allow identifiers to start with "_" (such identifiers are treated
    as lowercase idents).

* Objects:
  - Added "protected" methods (visible only from subclasses, can be hidden
    in class type declared in module signature).
  - Objects can be compared using generic comparison functions.
  - Fixed compilation of partial application of object constructors.
 
* Type system:
  - Occur-check now more strict (all recursions must traverse an object).
  - A few bugs fixed.

* Run-time system:
  - A heap compactor was implemented, so long-running programs can now
    fight fragmentation.
  - The meaning of the "space_overhead" parameter has changed.
  - The macros Push_roots and Pop_roots are superseded by Begin_roots* and
    End_roots.
  - Bytecode executable includes list of primitives used, avoids crashes
    on version mismatch.
  - Reduced startup overhead for marshalling, much faster marshalling of
    small objects.
  - New exception Stack_overflow distinct from Out_of_memory.
  - Maximum stack size configurable.
  - I/O revised for compatibility with compactor and with native threads.
  - All C code ANSIfied (new-style function declarations, etc).
  - Threaded code work on all 64-bit processors, not just Alpha/Digital Unix.
  - Better printing of uncaught exceptions.

* Both compilers:
  - Parsing: more detailed reporting of syntax errors (e.g. shows
    unmatched opening parenthesis on missing closing parenthesis).
  - Check consistency between interfaces (.cmi).
  - Revised rules for determining dependencies between modules.
  - Options "-verbose" for printing calls to C compiler, "-noassert"
    for turning assertion checks off.

* Native-code compiler:
  - Machine-dependent parts rewritten using inheritance instead of
    parameterized modules.
  - GC bug in value let rec fixed.
  - Port to Linux/Alpha.
  - Sparc: cleaned up use of %g registers, now compatible with Solaris threads.

* Top-level interactive system:
  - Can execute Caml script files given on command line.
  - Reads commands from ./.ocamlinit on startup.
  - Now thread-compatible.

* Standard library:
  - New library module: Lazy (delayed computations).
  - New library module: Marshal.  Allows marshalling to strings and
    transmission of closures between identical programs (SPMD parallelism).
  - Filename: "is_absolute" is superseded by "is_implicit" and "is_relative".
    To adapt old programs, change "is_absolute x" to "not (is_implicit x)"
    (but the new "is_relative" is NOT the opposite of the old "is_absolute").
  - Array, Hashtbl, List, Map, Queue, Set, Stack, Stream:
    the "iter" functions now take as argument a unit-returning function.
  - Format: added "printf" interface to the formatter (see the documentation).
    Revised behaviour of simple boxes: no more than one new line is output
    when consecutive break hints should lead to multiple line breaks.
  - Stream: revised implementation, renamed Parse_failure to Failure and
    Parse_error to Error (don't you love gratuitous changes?).
  - String: added index, rindex, index_from, rindex_from.
  - Array: added mapi, iteri, fold_left, fold_right, init.
  - Added Map.map, Set.subset, Printexc.to_string.

* ocamllex: lexers generated by ocamllex can now handle all characters,
  including '\000'.

* ocamlyacc: fixed bug with function closures returned by parser rules.

* Debugger:
  - Revised generation of events.
  - Break on function entrance.
  - New commands start/previous.
  - The command loadprinter now try to recursively load required
    modules.
  - Numerous small fixes.

* External libraries:
  - systhreads: can now use POSIX threads; POSIX and Win32 threads are
    now supported by the native-code compiler.
  - dbm and graph: work in native code.
  - num: fixed bug in Nat.nat_of_string.
  - str: fixed deallocation bug with case folding.
  - win32unix: use Win32 handles instead of (buggy) VC++ emulation of Unix
    file handles; added gettimeofday.

* Emacs editing mode and debugger interface updated to July '97 version.

Objective Caml 1.05:
--------------------

* Typing: fixed several bugs causing spurious type errors.

* Native-code compiler: fixed instruction selection bug causing GC to
see ill-formed pointers; fixed callbacks to support invocation from a
main program in C.

* Standard library: fixed String.lowercase; Weak now resists integers.

* Toplevel: multiple phrases without intermediate ";;" now really supported;
fixed value printing problems where the wrong printer was selected.

* Debugger: fixed printing problem with local references; revised
handling of checkpoints; various other small fixes.

* Macintosh port: fixed signed division problem in bytecomp/emitcode.ml

Objective Caml 1.04:
--------------------

* Replay debugger ported from Caml Light; added debugger support in
  compiler (option -g) and runtime system. Debugger is alpha-quality
  and needs testing.

* Parsing:
  - Support for "# linenum" directives.
  - At toplevel, allow several phrases without intermediate ";;".

* Typing:
  - Allow constraints on datatype parameters, e.g. 
    type 'a foo = ... constraint 'a = 'b * 'c.
  - Fixed bug in signature matching in presence of free type variables '_a.
  - Extensive cleanup of internals of type inference.

* Native-code compilation:
  - Inlining of small functions at point of call (fairly conservative).
  - MIPS code generator ported to SGI IRIX 6.
  - Better code generated for large integer constants.
  - Check for urgent GC when allocating large objects in major heap.
  - PowerPC port: better scheduling, reduced TOC consumption.
  - HPPA port: handle long conditional branches gracefully,
    several span-dependent bugs fixed.

* Standard library:
  - More floating-point functions (all ANSI C float functions now available).
  - Hashtbl: added functorial interface (allow providing own equality
    and hash functions); rehash when resizing, avoid memory leak on
    Hashtbl.remove.
  - Added Char.uppercase, Char.lowercase, String.uppercase, String.lowercase,
    String.capitalize, String.uncapitalize.
  - New module Weak for manipulating weak pointers.
  - New module Callback for registering closures and exceptions to be
    used from C.

* Foreign interface:
  - Better support for callbacks (C calling Caml), exception raising
    from C, and main() in C. Added function to remove a global root.
  - Option -output-obj to package Caml code as a C library.

* Thread library: fixed bug in timed_read and timed_write operations;
  Lexing.from_function and Lexing.from_channel now reentrant.

* Unix interface: renamed EACCESS to EACCES (the POSIX name); added setsid;
  fixed bug in inet_addr_of_string for 64-bit platforms.

* Ocamlyacc: default error function no longer prevents error recovery.

* Ocamllex: fixed reentrancy problem w.r.t. exceptions during refill;
  fixed output problem (\r\r\n) under Win32.

* Macintosh port:
  - The makefiles are provided for compiling and installing O'Caml on
    a Macintosh with MPW 3.4.1.
  - An application with the toplevel in a window is forthcoming.

* Windows NT/95 port: updated toplevel GUI to that of Caml Light 0.73.

* Emacs editing mode and debugger interface included in distribution.


Objective Caml 1.03:
--------------------

* Typing:
  - bug with type names escaping their scope via unification with
    non-generalized type variables '_a completely fixed;
  - fixed bug in occur check : it was too restrictive;
  - fixed bug of coercion operators;
  - check that no two types of the same name are generated in a module
    (there was no check for classes);
  - "#install_printer" works again;
  - fixed bug in printing of subtyping errors;
  - in class interfaces, construct "method m" (without type) change
    the status of method m from abstract to concrete;
  - in a recursive definition of class interfaces, a class can now
    inherit from a previous class;
  - typing of a method make use of an eventual previously given type
    of this method, yielding clearer type errors.

* Compilation (ocamlc and ocamlopt):
  - fixed bug in compilation of classes.

* Native-code compilation:
  - optimization of functions taking tuples of arguments;
  - code emitter for the Motorola 680x0 processors (retrocomputing week);
  - Alpha/OSF1: generate frame descriptors, avoids crashes when e.g.
    exp() or log() cause a domain error; fixed bug with
    String.length "literal";
  - Sparc, Mips, HPPA: removed marking of scanned stack frames
    (benefits do not outweight cost).

* Standard library:
  - Arg.parse now prints documentation for command-line options;
  - I/O buffers (types in_channel and out_channel) now heap-allocated,
    avoids crashing when closing a channel several times;
  - Overflow bug in compare() fixed;
  - GC bug in raising Sys_error from I/O functions fixed;
  - Parsing.symbol_start works even for epsilon productions.

* Foreign interface: main() in C now working, fixed bug in library
  order at link time.

* Thread library: guard against calling thread functions before Thread.create.

* Unix library: fixed getsockopt, setsockopt, open_process_{in,out}.

* Perl-free, cpp-free, cholesterol-free installation procedure.


Objective Caml 1.02:
--------------------
* Typing: 
  - fixed bug with type names escaping their scope via unification
    with non-generalized type variables '_a;
  - keep #class abbreviations longer;
  - faster checking of well-formed abbreviation definitions;
  - stricter checking of "with" constraints over signatures (arity
    mismatch, overriding of an already manifest type).

* Compilation (ocamlc and ocamlopt):
  - fixed bug in compilation of recursive classes;
  - [|...|] and let...rec... allowed inside definitions of recursive
    data structures;

* Bytecode compilation: fixed overflow in linker for programs with
  more than 65535 globals and constants.

* Native-code compilation:
  - ocamlopt ported to HPPA under HP/UX, Intel x86 under Solaris 2,
    PowerMacintosh under MkLinux;
  - fixed two bugs related to floating-point arrays (one with "t array"
    where t is an abstract type implemented as float, one with
    comparison between two float arrays on 32 bit platforms);
  - fixed reloading/spilling problem causing non-termination of
    register allocation;
  - fixed bugs in handling of () causing loss of tail recursion;
  - fixed reloading bug in indirect calls.

* Windows NT/95 port:
  - complete port of the threads library (Pascal Cuoq);
  - partial port of the Unix library (Pascal Cuoq);
  - expansion of *, ? and @ on the command line.

* Standard library:
  - bug in in List.exists2 fixed;
  - bug in "Random.int n" for very large n on 64-bit machines fixed;
  - module Format: added a "general purpose" type of box (open_box);
    can output on several formatters at the same time.

* The "threads" library:
  - implementation on top of native threads available for Win32 and
    POSIX 1003.1c;
  - added -thread option to select a thread-safe version of the
    standard library, the ThreadIO module is no longer needed.

* The "graph" library: avoid invalid pixmaps when doing 
  open_graph/close_graph several times.

* The "dynlink" library: support for "private" (no re-export) dynamic loading.

* ocamlyacc: skip '...' character literals correctly.

* C interface: C code linked with O'Caml code can provide its own main()
  and call caml_main() later.


Objective Caml 1.01:
--------------------
* Typing: better report of type incompatibilities; 
  non-generalizable type variables in a struct...end no longer flagged
  immediately as an error;
  name clashes during "open" avoided.

* Fixed bug in output_value where identical data structures
  could have different external representations; this bug caused wrong
  "inconsistent assumptions" errors when checking compatibility of
  interfaces at link-time.

* Standard library: fixed bug in Array.blit on overlapping array sections

* Unmarshaling from strings now working.

* ocamlc, ocamlopt: new flags -intf and -impl to force compilation as
  an implementation/an interface, regardless of file extension;
  overflow bug on wide-range integer pattern-matchings fixed.

* ocamlc: fixed bytecode generation bug causing problems with compilation
  units defining more than 256 values

* ocamlopt, all platforms:
  fixed GC bug in "let rec" over data structures;
  link startup file first, fixes "undefined symbol" errors with some
  libraries.

* ocamlopt, Intel x86:
  more efficient calling sequence for calling C functions;
  floating-point wars, chapter 5: don't use float stack for holding
  float pseudo-registers, stack-allocating them is just as efficient.

* ocamlopt, Alpha and Intel x86: more compact calling sequence for garbage
  collection.

* ocamllex: generated automata no longer use callbacks for refilling
  the input buffer (works better with threads); character literals
  correctly skipped inside actions.

* ocamldep: "-I" directories now searched in the right order

* Thread library: incompatibilities with callbacks, signals, and
  dynamic linking removed; scheduling bug with Thread.wait fixed.

* New "dbm" library, interfaces with NDBM.

* Object-oriented extensions:
    instance variables can now be omitted in class types;
    some error messages have been made clearer;
    several bugs fixes.

Objective Caml 1.00:
--------------------

* Merge of Jerome Vouillon and Didier Remy's object-oriented
extensions.

* All libraries: all "new" functions renamed to "create" because "new"
is now a reserved keyword.

* Compilation of "or" patterns (pat1 | pat2) completely revised to
avoid code size explosion.

* Compiler support for preprocessing source files (-pp flag).

* Library construction: flag -linkall to force linking of all units in
a library.

* Native-code compiler: port to the Sparc under NetBSD.

* Toplevel: fixed bug when tracing several times the same function
under different names.

* New format for marshaling arbitrary data structures, allows
marshaling to/from strings.

* Standard library: new module Genlex (configurable lexer for streams)

* Thread library: much better support for I/O and blocking system calls.

* Graphics library: faster reclaimation of unused pixmaps.

* Unix library: new functions {set,clear}_nonblock, {set,clear}_close_on_exec,
{set,get}itimer, inet_addr_any, {get,set}sockopt.

* Dynlink library: added support for linking libraries (.cma files).

Caml Special Light 1.15:
------------------------

* Caml Special Light now runs under Windows NT and 95. Many thanks to
Kevin Gallo (Microsoft Research) who contributed his initial port.

* csllex now generates tables for a table-driven automaton.
The resulting lexers are smaller and run faster.

* Completely automatic configuration script.

* Typing: more stringent checking of module type definitions against
manifest module type specifications.

* Toplevel: recursive definitions of values now working.

* Native-code compiler, all platforms:
        toplevel "let"s with refutable patterns now working;
        fixed bug in assignment to float record fields;
        direct support for floating-point negation and absolute value.

* Native-code compiler, x86: fixed bug with tail calls (with more than
4 arguments) from a function with a one-word stack frame.

* Native-code compiler, Sparc: problem with -compact fixed.

* Thread library: support for non-blocking writes; scheduler revised.

* Unix library: bug in gethostbyaddr fixed; bounds checking for read,
write, etc.

Caml Special Light 1.14:
------------------------

* cslopt ported to the PowerPC/RS6000 architecture. Better support for
AIX in the bytecode system as well.

* cslopt, all platforms: fixed bug in live range splitting around catch/exit.

* cslopt for the Intel (floating-point wars, chapter 4):
implemented Ershov's algorithm to minimize floating-point stack usage;
out-of-order pops fixed.

* Several bug fixes in callbacks and signals.

Caml Special Light 1.13:
------------------------

* Pattern-matching compilation revised to factor out accesses inside
matched structures.

* Callbacks and signals now supported in cslopt.
Signals are only detected at allocation points, though.
Added callback functions with 2 and 3 arguments.

* More explicit error messages when a native-code program aborts due
to array or string bound violations.

* In patterns, "C _" allowed even if the constructor C has several arguments.

* && and || allowed as alternate syntax for & and or.

* cslopt for the Intel: code generation for floating-point
operations entirely redone for the third time (a pox on whomever at
Intel decided to organize the floating-point registers as a stack).

* cslopt for the Sparc: don't use Sparc V8 smul and sdiv instructions,
emulation on V7 processors is abysmal.

Caml Special Light 1.12:
------------------------

* Fixed an embarrassing bug with references to floats.

Caml Special Light 1.11:
------------------------

* Streams and stream parsers a la Caml Light are back (thanks to
Daniel de Rauglaudre).

* User-level concurrent threads, with low-level shared memory primitives
(locks and conditions) as well as channel-based communication primitives
with first-class synchronous events, in the style of Reppy's CML.

* The native-code compiler has been ported to the HP PA-RISC processor
running under NextStep (sorry, no HPUX, its linker keeps dumping
core on me).

* References not captured in a function are optimized into variables.

* Fixed several bugs related to exceptions.

* Floats behave a little more as specified in the IEEE standard
(believe it or not, but x < y is not the negation of x >= y).

* Lower memory consumption for the native-code compiler.

Caml Special Light 1.10:
------------------------

* Many bug fixes (too many to list here).

* Module language: introduction of a "with module" notation over
signatures for concise sharing of all type components of a signature;
better support for concrete types in signatures.

* Native-code compiler: the Intel 386 version has been ported to
NextStep and FreeBSD, and generates better code (especially for
floats)

* Tools and libraries: the Caml Light profiler and library for
arbitrary-precision arithmetic have been ported (thanks to John
Malecki and Victor Manuel Gulias Fernandez); better docs for the Unix
and regexp libraries.

Caml Special Light 1.07:
------------------------

* Syntax: optional ;; allowed in compilation units and structures
(back by popular demand)

* cslopt: 
generic handling of float arrays fixed
direct function application when the function expr is not a path fixed
compilation of "let rec" over values fixed
multiple definitions of a value name in a module correctly handled
no calls to ranlib in Solaris

* csltop: #trace now working

* Standard library: added List.memq; documentation of Array fixed.

Caml Special Light 1.06:
------------------------

* First public release.