ocaml/Changes

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

* Language:
  - New class language.  See http://...
    for an overview, and the manual for reference.
  - 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: simplified code generation for jump tables.
  - 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 with 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 @).
  - Oo.copy removed.
  - 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, tie, 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.

* 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.