root/trunk/RELEASE_NOTES.txt

================================================================
Logtalk - Open source object-oriented logic programming language
Release 2.32.1

Copyright (c) 1998-2008 Paulo Moura.  All Rights Reserved.
================================================================


RELEASE NOTES
=============


2.32.1 - July 7, 2008

    Restored the redefined entity warnings for back-end Prolog compilers 
    that support multifile predicates. Simplified updating of the runtime 
    tables when compiling and loading source files with back-end Prolog 
    compilers that don't support multifile predicates.

    Changed the representation of the runtime tables for loaded entities 
    in order to drop the need of a "functors clause" per entity. This avoids 
    some redundancy on the representation of entity functors and also helps 
    reducing a bit the size of the generated Prolog files.

    When reloading an object, also clean all entries in the event handlers 
    table where the object plays the role of a monitor.

    Modified the Logtalk runtime to clean all lookup caches when compiling 
    and loading source files (instead of doing it only when the files 
    redefine existing entities).

    Corrected a bug that prevented using predicate aliases with the :/1 
    control construct without static binding.

    Updated the CxProlog config file to take advantage and require the new 
    0.97.1 version (which implements some more ISO Prolog predicates and 
    expands support for text encodings).

    Updated the B-Prolog config file to take advantage and require the new 
    7.1 version (which adds support for the multifile/1 predicate directive).

    Updated the SWI-Prolog config file notes about possible compatibility 
    issues with the default setting of the proprietary "iso" Prolog flag 
    to "true".

    Updated the SWI-Prolog hook file, "swihook.pl", to avoid hijacking the 
    arguments of use_module/1-2 calls (which resulted in wrongly loading 
    Logtalk libraries with the same name as the SWI-Prolog library modules 
    we intended to load).

    Updated the "k6.config" config file for the K-Prolog 6.0.3 release.
    Renamed the K-Prolog 5.1.x config file from "k.config" to "k5.config" 
    to avoid being mistaken for the K-Prolog 6.0.x config file.

    Renamed the SICStus Prolog 3 config file from "sicstus.config" to 
    "sicstus3.config" to avoid being mistaken for the SICStus Prolog 4 
    config file.

    Improved the Prolog migration guide on converting code that makes use 
    of multifile predicates.

    Updated the support for the Pygments syntax highlighter to avoid marking 
    as errors non-standard directives.


2.32.0 - June 16, 2008

    Updated the Logtalk compiler and runtime to use multifile predicates for 
    the runtime tables of loaded entities and entities relations. This is 
    necessary to generate sensible intermediate Prolog code for large files 
    with tens of thousands of objects. The workaround of using the directive 
    initialization/1 is still available (for now) for Prolog compilers that 
    fail to support the thirteen years old ISO Prolog standard.

    Updated the Logtalk runtime error handler to test for non-instantiated 
    exception terms. Thanks to Joerg Schuster for the bug report.

    Corrected two bugs in the implementation of the built-in meta-predicate 
    threaded/1 when canceling individual threads. The first bug resulted from 
    out-of-order thread status messages. The second bug resulted from a leak 
    of thread results between calls to the threaded/1 predicate. Changed the 
    thread cancellation process to not automatically releasing any locks, 
    leaving that task to a catcher associated to the thread goal.

    Added a new default compiler option, multifile_directive, to all config 
    files. Possible values are "supported" and "unsupported".

    Added instructions on how to patch the Logtalk compiler in order to use 
    Quintus Prolog as the back-end compiler.

    Removed from the YAP POSIX integration script the command-line options 
    setting the initial stack, heap, and tail data area sizes. These settings
    are no longer necessary for recent YAP versions.

    Updated the Windows installer script to search the registry for the 
    location of the YAP installation (for YAP 5.1.3 or later versions).

    Added missing implementation of the predicate as_dictionary/2 to the 
    "bintree" library object. Thanks to Victor Noel for the bug report.

    Updated all the search methods in the "searching" example to delegate 
    checking for cycles to the state space being searched (thus allowing 
    state descriptions to carry additional information that should not be 
    taken into account when comparing states). Updated the "salt" example 
    to support heuristics.

    Updated the "mtbatch" example to include a benchmark test for competitive 
    or-parallelism applied to state-space search (using the resources from the
    "searching" example). Improved the example documentation.

    Added a filetype plugin for the Vim text editor. Updated the installation 
    instructions. Updated the syntax coloring support to properly highlight 
    quoted atoms and strings in the opening directive of parametric objects. 
    Fixed an auto-indentation bug when opening and closing a conditional 
    block in a single line in the last goal a predicate clause body. Thanks 
    to Victor Noel for the bug report.

    Corrected missing installation of the "VERSION.txt" file when building 
    Linux RPMs.


2.31.6 - May 26, 2008

    Fixed a Logtalk runtime bug when using the :/1 control construct to 
    call a predicate defined in a category extended by a category that 
    is imported by the object making the call.

    Fixed a Logtalk compiler bug when compiling an alias/3 predicate 
    directive within a category that extends other categories.

    Fixed a Logtalk compiler bug when compiling a class that imports a  
    category that extends other categories. Thanks to Victor Noel for 
    the bug report.

    Small performance improvement to the caching of category predicates 
    when using static binding.

    Removed from the YAP config file the definition of the forall/2 
    predicate, which have been added as a built-in predicate in YAP 
    version 5.1.3 (the current YAP CVS version must be used; the last 
    stable version, 5.1.2, is broken on Windows). Added support for 
    the proprietary if/1, else/0, elif/1, and endif/0 directives (when 
    used outside Logtalk entities).

    Updated the SWI-Prolog config file with support for the proprietary 
    if/1, else/0, elif/1, and endif/0 directives (when used outside 
    Logtalk entities).

    Improved the "complements" example, moving the category initialization 
    goal to the beginning of the example source file.

    Added support for the Pygments syntax highlighter (co-developed with 
    Clara Dimene).

    Added a new sample Logtalk source file for testing syntax coloring 
    support.

    Added missing auto-completion keywords for the ISO Prolog standard 
    arithmetic functions to the SubEthaEdit, TextMate, Notepad++, jEdit, 
    Vim, and Smultron text editors.

    Corrected a bug in the SubEthaEdit syntax coloring support for the 
    imports_category/2-3 built-in predicate. Added some missing files 
    (license and mode settings) to the SubEthaEdit mode bundle.

    Corrected a bug in the Vim syntax coloring support for the ISO Prolog 
    built-in predicate current_char_conversion/2 and added missing support 
    for for quoted atom escape sequences.

    Corrected a bug in the jEdit syntax coloring support for hexadecimal 
    numbers and added missing support for the extends_category/2-3 and 
    at_end_of_stream/0 built-in predicates.

    Added missing support for the syntax coloring of the external call 
    Logtalk control construct, {}/1, to the Highlight package. Corrected 
    a bug with 0'Char constants and with octal and hexadecimal escape 
    sequences.

    Added missing support for the syntax coloring of the external call 
    Logtalk control construct, {}/1, and for quoted atom escape sequences 
    to the TextMate text editor.

    Added missing support for the syntax coloring of quoted atom escape 
    sequences and of the built-in predicate at_end_of_stream/0 to the 
    Source-highlight package.

    Added missing support for the syntax coloring of the built-in predicate 
    at_end_of_stream/0 and of the scope operator ::/2 to the Kate text editor.
    Improved syntax coloring of parametric object opening directives.

    Added missing support for the syntax coloring of the built-in predicate 
    unify_with_occurs_check/2 to the Emacs text editor. Corrected a bug in 
    the syntax coloring of arithmetic comparison operators.

    Added missing support for the syntax coloring of quoted atom escape 
    sequences and of the built-in control construct call/1 to the 
    GtkSourceView 2.x text widget.

    Added missing support for the syntax coloring of variables, of quoted 
    atom escape sequences, of the built-in method clause/2, of the external 
    call Logtalk control construct {}/1, and of variables to the Nedit text 
    editor. Corrected a bug with 0'Char constants and corrected some typos 
    in the support for the current_event/2, implements_protocol/2-3, and 
    abolish_category/1 built-in predicates.


2.31.5 - April 29, 2008

    Added support for checking arithmetic expressions for calls to 
    non-portable functions when using the "portability" compiler flag.

    Updated the implementation of the threaded/1 built-in predicate to 
    ensure that thread creation errors (usually, virtual memory address 
    space exhaustion) result in the corresponding exception rather than 
    in a non-terminating call. Improved cancellation of all individual 
    threads when one of them terminates with an exception or a failure.

    Simplified the terms used to post individual results from threaded/1
    calls to the queue associated to the call.

    Corrected a bug in the built-in predicate threaded/1 when its argument 
    is a conjunction (disjunction) of conjunctions (disjunctions).

    Added a workaround for a mutex creation error when reloading a source 
    file with entities defining synchronized predicates.

    Updated the Logtalk runtime to unlock all mutexes hold by a thread when 
    upon thread cancellation.

    Corrected a Logtalk compiler bug that allowed a predicate to be declared 
    both dynamic and synchronized. Thanks to Paul Crocker for the bug report.

    Corrected a Logtalk compiler bug where local definition clauses for 
    dynamic predicates are being generated for categories. Thanks to Victor 
    Noel for the bug report.

    Updated the YAP and SWI-Prolog config files to set the default value of 
    the "tmpdir" flag depending on the host operating-system. Added missing
    declaration for the multi-threading predicate thread_initialization/1.

    Added missing declarations for some proprietary built-in meta-predicates 
    to the B-Prolog config file.

    Corrected a bug in the SWI-Prolog config file in the declaration of the 
    proprietary built-in meta-predicate "soft cut". Thanks to Victor Noel 
    for the bug report.

    Updated the XSB config file to use the new optimized call/N predicates 
    found on the current XSB CVS version.

    Added an integration script, "xsbmt64lgt", for using Logtalk with the 
    multi-threaded, 64 bits version of XSB.

    Simplified building of MacOS X Installer packages. Updated the Windows 
    installation script to use the "C:\lgtsvn" as base. Simplified manual 
    installation instructions.

    Updated the definitions of the predicate valid/1 for the library objects 
    "list", "list(Type)", "numberlist", "set", "set(Type)", "varlist" to fail 
    for lists with unbound tails after discussion with Jan Wielemaker and 
    Ulrich Neumerkel.

    Corrected a bug in the library object "lgtunit" when running "throws" 
    tests (make sure the generated exception is subsumed by the expected 
    exception). Added a "lgtunit_loader" loader utility file for loading 
    the Logtalk unit test library.

    Added a simple example, "debug_hooks", of using compilation hooks and 
    term expansion for conditional compilation of debug statements.

    Updated the "primes" multi-threading example to allow any number of 
    threads to be used in the computation of primes numbers.

    Added a new multi-threading example, "integration", implementing 
    Recursive Gaussian Quadrature Methods for Numerical Integration for 
    functions of a single variable, contributed by Paul Crocker.

    Added a new multi-threading example, "mtbatch", for benchmarking 
    multi-threading performance.

    Added a new example, "ack", implementing the Ackermann function (general 
    recursive function).

    Added support for using the Highlight package (version 2.6.9 or later) 
    by Andre Simon with Logtalk source files.

    Updated the TextMate Logtalk bundle and its configuration instructions 
    to make the "Compile" and "Generate ..." commands more general, making 
    it compatible with most Prolog compilers. Added syntax coloring for 
    standard arithmetic functions. Added a command for generating plain text 
    files from XML documenting files.

    Corrected a syntax coloring bug with character codes using the 0'Char 
    notation in the SubEthaEdit 2.x and Vim text editors and in the
    source-highlight package.

    Removed some redundant regular expressions from the jEdit text editor 
    syntax coloring support files.

    Corrected syntax coloring bugs with variables starting with underscores 
    (including anonymous variables) and with atoms containing an underscore 
    in the Emacs text editor. Thanks to Joerg Schuster for the bug report.

    Updated the Logtalk grammar documentation to reflect the changes to 
    category relations introduced in version 2.31.0.

    Added a "lgttxt.xsl" XSLT style-sheet and two shell scripts, "lgt2txt.sh" 
    and "lgt2txt.js", for converting XML documenting files into text files.
    Updated the "lgt2*.sh" shell scripts for POSIX compliance, removing 
    dependencies on bash shell features.

    Updated the "lgtxml.xsl" XSLT style-sheet to ensure that the generated 
    HTML files are fully compliant with the HTML 4.01 standard.

    Updated the Debian installer package shell scripts for POSIX compliance, 
    removing dependencies on bash shell features.


2.31.4 - February 20, 2008

    Optimized the performance of threaded/1 calls by using a per-call 
    message queue for collecting the individual call results and by 
    using the message queue identifier as a tag for the individual 
    calls. This solution avoids runtime synchronization of a large 
    number of threads on the same message queue, simplifies compilation 
    and runtime handling of threaded/1 calls, and simplifies thread 
    cancellation, eliminating any risk of dangling individual thread 
    results.

    Removed two redundant calls to the built-in predicate thread_exit/1 
    on the Logtalk compiler.

    Corrected a bug where a competitive or-parallelism call would 
    prematurely fail with one or more individual calls still pending.

    Corrected a bug where a competitive or-parallelism call would succeed 
    when all the individual calls had failed.

    Corrected a bug when compiling calls to the Logtalk multi-threading 
    built-in predicates made from the top-level interpreter, i.e. from 
    within the pseudo-object "user".

    Added foreach/3, forto/5, and fordownto/5 meta-predicates to the 
    library object "loop". Updated the definitions of the forto/3-4 
    and fordownto/3-4 meta-predicates to allow the use of arithmetic 
    expressions as arguments for convenience and clarity.

    Corrected a bug in the implementation of the predicate lookup/3 in 
    the library object "bintree".

    Added a multi-threading example of the Fast Fourier Transform, "fft", 
    contributed by Paul Crocker.

    Corrected a bug in the implementation of the bisection algorithm in 
    the multi-threading example "functions". Added an implementation of 
    the MATLAB humps function (contributed by Paul Crocker).

    Updated the multi-threading example "sorting" to workaround a mutex 
    performance issue with XSB when generating lists of random numbers.

    Updated support for the TextMate text editor. Added a command for 
    generating the PDF documentation of open source files. Added missing 
    tab triggers to the Logtalk snippets. Updated installation notes.

    Corrected a bug in the jEdit syntax coloring support for the is/2 
    operator.


2.31.3 - January 28, 2008

    Added a "VERSION.txt" file that is used to check compatibility between 
    an existing Logtalk user folder (whose path is stored in the LOGTALKUSER 
    environment variable) and a new Logtalk version.

    Updated the POSIX Prolog integration scripts to check for an outdated 
    Logtalk user folder, creating a new one if necessary by running the 
    "cplgtdirs" script (a backup is automatically made of the old directory).

    Updated the Windows installer to create a registry key with the Logtalk 
    version number and to check for an outdated Logtalk user folder.

    Changed the predicate used to load Prolog files, adding an additional 
    argument that represents a list of load/compile options (notably,
    encoding/1, which is necessary for supporting source files encodings 
    such as ISO-8859-X).

    Updated the SICStus Prolog 4 config file to also accept UCS-2 encodings 
    when using the encoding/1 directive (UCS-2 is subsumed by UTF-16).

    Added a workaround to the Quintus Prolog integration scripts for its 
    lack of support for expanding environment variables in file names.


2.31.2 - January 21, 2008

    Extended compatibility of the experimental Logtalk encoding/1 directive 
    to CxProlog 0.96.3 and SICStus Prolog 4.0.2 and improved support for YAP 
    and SWI-Prolog.

    Improved source file encoding handling by ensuring that a BOM present 
    in a source file being compiled is inherited by the generated Prolog 
    and XML files.

    Changed the atoms used to represent different encodings when using the 
    encoding/1 directive; Logtalk now uses the encoding names specified by 
    IANA (using the preferred MIME name whenever available).

    Updated the Logtalk compiler to throw an exception when the specified 
    encoding is not supported by the used back-end Prolog compiler.

    Updated the "encodings" example to use the new encoding names and added 
    new source files using UTF-16 and UTF-32 text encodings.

    Added POSIX and Windows integration scripts for Quintus Prolog.


2.31.1 - January 3, 2008

    Duplicated the range of threaded_call/2 tags for multi-threading Prolog 
    compilers with bounded integers.

    Updated the YAP config file to set the flag "language" to "iso". This 
    is not strictly necessary to run Logtalk with YAP but it helps prevent 
    nasty surprises when writing portable applications that rely on ISO 
    Prolog semantics.

    Updated the SWI-Prolog integration script to test for the availability of
    the XPCE library before trying to load the "xpcehook.pl" XPCE hook file.

    Updated the Linux (RMP and Debian) and MacOS X package build scripts to 
    include Prolog version compatibility information.

    Updated the "tak" multi-threading example to allow parameterization of 
    the number of threads to use.

    Updated the "sorting", "hanoi", and "fibonacci" multi-threading examples 
    to interpret the object parameter as the number of leaf threads (i.e. 
    working threads that will not recursively create additional threads).

    Updated the TextMate text editor support to include commands to compile 
    and to automatically generate the XHTML documentation of open source 
    files.


2.31.0 - December 21, 2007

    Added a new built-in protocol, "expanding", declaring goal_expansion/2
    and term_expansion/2 public predicates.

    Added compiler support for user-defined goal expansion hooks. Changed 
    the implementation of compiler term and goal expansion hooks to use 
    object-defined predicates term_expansion/2 and goal_expansion/2.
    Changed the compiler option "hook" to accept object identifiers.

    Allow a category to explicitly complement an existing object, thus 
    providing functionality similar to Objective-C categories. Added 
    complements_object/2 built-in predicate. Added a new example, 
    "complements", illustrating the new category functionality.

    When constructing a new category from other categories, the relation 
    "extends" is now used instead of the relation "imports". The relation 
    "imports" is now only used when an object imports a category. Added  
    extends_category/2-3 built-in predicates.

    Modified the built-in predicate define_events/5 to throw an existence 
    error instead of failing when the specified monitor object does not 
    exists. 

    Updated the Logtalk compiler to convert version numbers to atoms when 
    generating XML documenting files (thus avoiding problems with some 
    Prolog compilers that resulted in version numbers with a large number 
    of fractional digits).

    Improved updating of runtime bookkeeping tables when loading source 
    files.

    Renamed the predicate property "alias/1" to "alias_of/1" in order to 
    disambiguate its meaning.

    Added a new config file, "k6.config", for the K-Prolog 6.0 beta 
    version.

    Updated the B-Prolog config file to recognize mode/1 directives.
    Added some missing meta-predicate specifications to the config files 
    of XSB and YAP.

    Updated the Windows GUI installer to support running Logtalk with 
    CxProlog 0.96.1 and later versions.

    Added two new multi-threading examples, "fibonacci" and "hanoi", and 
    corrected a bug in the recursive creation of threads on the "sorting" 
    example. Updated the "primes" multi-threading example to also support 
    eight threads.

    Updated the "hooks" example for illustrating goal expansion hooks in 
    addition to term expansion hooks.

    Updated the "engines" example for compliance with the changes made 
    to category relations.

    Added syntax coloring support for the new goal_expansion/1, 
    complements_object/2, and extends_category/2-3 predicates to all 
    supported text editors.

    Updated the TextMate code snippets to use the TM_FULLNAME variable 
    instead of the deprecated "niutil" command to retrieve the user full 
    name. Thanks to Michael Sheets for the update. 


2.30.8 - November 9, 2007

    Fixed bug in the compilation of synchronized predicates that breaks 
    Logtalk on single-threaded Prolog compilers.


2.30.7 - November 5, 2007

    Updated the multi-threading built-in predicates threaded_notify/1 and 
    threaded_wait/1 to accept lists of notifications.

    Added a new read-only compiler flag, "context_switching_calls", allowing 
    context switching calls to be disabled (they are enabled by default).

    Updated the B-Prolog config file to recognize eager_consume/1 directives.
    Updated the XSB config file to recognize use_subsumptive_tabling/1,
    use_variant_tabling/1, index/1, thread_private/1, and thread_shared/1 
    directives.
    Updated the YAP config file to recognize thread_local/1 directives.
    Updated the SICStus Prolog config files to recognize volatile/1 directives.
    Updated the SWI-Prolog config file to recognize thread_local/1, index/1, 
    and hash/1 directives.

    Changed the backup directory names generated by the "cplgtdirs.*" shell 
    scripts to not include whitespace characters.

    Updated the "xsbmtlgt.sh" integration script to start XSB-MT using the 
    new command-line option "--shared_predicates" (requires current XSB CVS 
    version). Updated the Windows GUI installer to support running Logtalk 
    with XSB-MT.

    Added a multi-threading example, "barriers", of barrier synchronization.

    Updated the "functions" example sample queries for compatibility with the 
    ISO Prolog standard regarding representation of float numbers.

    Added a workaround for a parsing bug in XSB while compiling the "sicstus" 
    example.


2.30.6 - October 21, 2007

    Replaced calls to the proprietary current_thread/2 predicate in the 
    Logtalk runtime by calls to the thread_property/2 predicate as per 
    the ISO DTR on multi-threading predicates. Added a goal_expansion/2 
    clause to the SWI-Prolog config file to automatically switch between 
    the current_thread/2 and thread_property/2 predicates depending on 
    availability.

    Changed handling of the encoding/1 directive by the Logtalk compiler in 
    order to improve compatibility with YAP and SICStus Prolog. Removed from 
    the config files the now obsolete '$lgt_set_stream_encoding'/2 predicate 
    definition. Renamed the compiler option "supports_encoding_dir" to 
    "encoding_directive" and changed its possible values to "unsupported", 
    "full" (used in both Logtalk source files and compiler generated Prolog 
    files), and "source" (used only in Logtalk source files).

    Renamed compiler option "underscore_vars" to "underscore_variables".
    Renamed compiler option "supports_break_predicate" to "break_predicate".

    Improved the performance of recursive predicate definitions synchronized 
    by mutexes. Explicitly create all mutexes used by an entity at load time 
    for compatibility with XSB. Several changes to multi-threading support in 
    order to improve compatibility with current and forthcoming versions of 
    YAP, SWI-Prolog, and XSB.

    Updated the Logtalk compiler for compatibility with both logical and 
    immediate update semantics when compiling synchronized predicates.

    Updated the meta-predicate compilation sanity checks to verify the 
    existence of the minimum number of normal arguments in a clause head 
    required by the closure of maximum arity.

    Added a workaround for the lack of built-in support for character 
    unbuffered input when using the Logtalk built-in debugger to the config 
    files of ALS Prolog, B-Prolog, Ciao, CxProlog, IF/Prolog, JIProlog, 
    Prolog II+, SICStus Prolog, XSB, and YAP. Thanks to Parker Jones for the 
    bug report.

    Updated the YAP config file to auto-detect working Unicode support when 
    setting the "encoding_directive" compiler option.

    Updated the XSB config file to auto-detect multi-threading support
    when setting the "threads" compiler option. Added an integration script 
    (xsbmtlgt.sh) and supporting files for the multi-threaded version of XSB 
    (requires current development version, available from the XSB CVS server).

    Added a MacPorts portfile for building MacOS X installer packages.

    Added a BOM to the "babel.lgt" UTF-8 file in the "encodings" example in 
    order to improve compatibility with SICStus Prolog.

    Updated the library object "random" by replacing the synchronized/0 
    directive by a synchronized/1 directive listing only the predicates 
    that modify the random number seed.

    Added syntax coloring support for the GtkSourceView 2.x text widget 
    (used e.g. on the Gnome's Gedit text editor and on the MonoDevelop IDE).
    Removed syntax coloring for the obsolete atomic/1 predicate directive 
    from the support files of Source-highlight, Emacs, SubEthaEdit, jEdit, 
    and Kate. Optimized the regular expressions used in most syntax coloring 
    configuration files of supported text editors.


2.30.5 - September 19, 2007

    Added new multi-threading built-in predicates threaded_call/2, 
    threaded_once/2, threaded_exit/2, and threaded_peek/2. These new 
    predicates support the use of threaded call identifier tags in order to 
    link specific threaded_call/2 and threaded_once/2 calls to specific 
    threaded_exit/2 and threaded_peek/2 calls. Extended the "nondet" example 
    in order to illustrate the new functionality.

    Changed the implementation of the built-in predicate threaded_exit/1 in 
    order to avoid blocking when its argument is subsumed by the argument of 
    the corresponding threaded_call/1 call instead of being a variant.

    Updated the Logtalk compiler to encapsulate resource errors inside 
    error/2 exception terms (as specified in the ISO Prolog core standard).

    Corrected a bug in the library object "lgtunit" (wrong arity on two 
    failed_test/2 predicate calls).

    Corrected two problems with the "testing" example: a wrong call on the 
    object "dyn_tests" and a missing entry in the "libpaths.pl" file. Removed 
    two pointless dynamic predicate directives in the "buffer" example.

    Improved documentation of multi-threading programming and predicate 
    properties. Corrected the reference manual page describing the threaded/0 
    directive.

    Simplified installation scripts by moving shared distribution cleaning 
    code into the "cleandist.sh" script. Updated the "install.sh" script to 
    set the installation prefix to "/usr" on Debian systems. Updated the 
    Linux RPM spec file in order to clean the building directory after the 
    package creation.


2.30.4 - August 22, 2007

    Allow the argument of {}/1 calls to be a variable at compile time.

    Updated the Qu-Prolog config file to match and require version 8.1 and 
    added a "qplgt" integration script.

    Updated the XSB config file to match and require version 3.1 and to 
    take advantage of the compiler option optimize/1 when loading Logtalk 
    generated Prolog intermediate files.

    Added a new library object, "lgtunit", providing preliminary support for 
    writing and running unit tests. Added a new example, "testing", defining 
    sample unit tests.

    Added a new multi-threading example, "threads/tak", implementing the 
    Takeuchi function (recursive arithmetic).

    Updated the "threads/philosophers" example to use notifications instead 
    of a dynamic predicate for representing chopstick availability. Added an 
    alternative implementation using a parametric object. Improved example 
    documentation.

    Updated the "benchmarks" example to allow comparisons between calls to 
    imported category predicates and calls to local object predicates.

    Updated Emacs support in order to fix problems with the syntax-coloring 
    of some Logtalk built-in predicates and applied a patch contributed by 
    Nicolas Pelletier to workaround a compatibility problem with XEmacs.

    Updated jEdit support in order to fix a problem with the syntax-coloring 
    of the :/1 control construct.


2.30.3 - July 9, 2007

    Updated the multi-threading built-in predicate threaded/1 to support 
    both conjunctions of goals (akin to and-parallelism) and disjunctions 
    of goals (akin to or-parallelism) as an argument.

    Removed the experimental threaded_race/1 multi-threading built-in 
    predicate (its or-parallelism functionality is subsumed by the updated 
    threaded/1 predicate).

    Corrected a bug in the implementation of the multi-threading built-in 
    predicate threaded_exit/1 when there are more than one thread running 
    the same non-deterministic goal (the fix ensures that all alternative 
    solutions per threaded_exit/1 call come from the same computing thread). 
    Thanks to Paul Crocker for the suggested bug fix solution.

    Updated the sample queries in the "threads/buffer"/SCRIPT.txt" file to 
    match the updated entities in the example.

    Updated the "threads/functions" example to use the new version of the 
    threaded/1 multi-threading built-in predicate.


2.30.2 - June 24, 2007

    Updated the Logtalk compiler to throw a compilation error when duplicated 
    or conflicting predicate scope directives are found.

    Updated the Logtalk compiler to correct a cosmetic glitch when reporting 
    compilation errors.

    Updated the Logtalk compiler to check for mismatches between the argument 
    of this/1 calls and the parametric object identifier.

    Corrected a bug in the implementation of the multi-threading built-in 
    predicate threaded_ignore/1.

    Revamped the "threads/buffer" example to support setting the buffer 
    maximum number of items.

    Added a new DCG example, "dcgs/morse.lgt", for parsing messages in Morse 
    code.

    Extended the "parametric" example to illustrate a solution for dealing 
    with inheritance when defining "setter" predicates/methods that return 
    updated object identifiers.


2.30.1 - June 12, 2007

    Added a new, experimental control construct, :/1, for calling imported 
    category predicates without using message sending mechanisms.

    Added preliminary support for static binding when calling imported 
    category using the new :/1 control construct for categories compiled 
    and loaded using the compiler option "reload(skip)".

    Added a new control construct, <</2, which allows proving a goal within 
    the context of a specified object. Useful for debugging and for writing 
    object unit tests.

    Improved multi-threading support in order to make the built-in predicate 
    threaded_exit/1 generate an exception instead of blocking indefinitely 
    waiting for a reply from a non-existing thread.

    Updated the Logtalk compiler to generate an error when compiling from a 
    source file new definitions for built-in entities.

    Updated the Logtalk compiler to generate simpler clauses for the book-
    keeping table of local predicate definitions for parametric entities.

    Updated the config files for ECLiPSe, Ciao Prolog, SICStus Prolog, 
    SWI-Prolog, and YAP to use the renamed hook predicates introduced in 
    Logtalk 2.30.0 for parsing Prolog proprietary directives.

    Updated the "benchmarks" example to compare the performance of calls to 
    imported category predicates when using a message to "self" and a direct 
    call.


2.30.0 - May 28, 2007

    Added preliminary support for static binding when sending messages to 
    objects compiled and loaded using the compiler option "reload(skip)".

    Allow non-instantiated arguments at compile time for the multi-threading 
    built-in predicate threaded/1.

    Simplified and optimized the implementation of Logtalk multi-threading 
    support. Use a single dispatcher thread for all objects instead of each 
    object running its own dispatcher in order to minimize the number of 
    created threads (which can be problematic on 32 bits systems). Updated 
    the built-in predicate threaded/1 to make it deterministic and opaque to 
    cuts (similar to once/1).

    Updated the Logtalk built-in database methods to always interpret rules 
    whose body is the control construct true/0 as facts. Corrected a bug when 
    compiling dynamic predicates that would prevent using of the clause/2 
    built-in database method. Corrected a bug when using the Logtalk built-in 
    database method clause/2 with entities compiled in debug mode. Improved 
    predicate lookup caching when asserting and retracting dynamic facts.

    Improved detection and reporting of entity existence errors.

    Added a quit option, "q", to the Logtalk built-in debugger. Modified 
    the debugger behavior to automatically switch to trace mode when a spy 
    point is found.

    Added two new compiler options, "xmldir" and "tmpdir", allowing per 
    project definition of directories for storing XML documenting files 
    and for storing intermediate compilation files (e.g. Prolog files).
    Removed the config file predicate '$lgt_alt_directory'/2.
    Older config files are incompatible with this new Logtalk version.

    Added a shortcut to the Logtalk built-in predicate logtalk_load/1, {}/1,
    to all config files (defined there in order to be easy to comment it out 
    in case of conflict with some Prolog native feature or lack of compliance
    with the ISO Prolog standard regarding the definition of the {}/1 syntax.

    Allow the compiler flag "misspelt" to be set to "error".

    Updated the Logtalk compiler to not try to clean-up the dynamic predicates
    of redefined entities when reloading source files. Most Prolog compilers 
    already behave as expected when reloading the intermediate Prolog files 
    generated by the Logtalk compiler. For those Prolog compilers that do not 
    replace old definitions for dynamic predicates with the new ones, it is 
    not possible for Logtalk to implement a workaround that would work 
    correctly in all cases. Consult the "configs/NOTES.txt" file for more 
    information.

    Corrected a bug that prevents abolishing a dynamic entity loaded from a 
    source file. Thanks to Victor Noel for the bug report.

    Renamed the '$lgt_copy_pl_directive'/1 and '$lgt_rewrite_pl_directive'/2 
    config files predicates to '$lgt_rewrite_and_copy_pl_directive'/2 and 
    '$lgt_rewrite_and_recompile_pl_directive'/2. 

    Updated the config file for B-Prolog to match (and require) the new 7.0 
    version; updated and simplified the corresponding integration scripts.

    Updated the XSB POSIX integration script to automatically detect if we 
    are running the XSB stable version of the XSB CVS version.

    Added basic support for tabling to the config files of B-Prolog, XSB, 
    and YAP. Added a simple example of using tabling directives within 
    objects.

    Updated the SWI-Prolog and YAP config files to automatically detect if 
    the Prolog systems have been compiled with multi-threading support and 
    to set the Logtalk compiler flag "threads" accordingly.

    Corrected a bug when running Logtalk with SWI-Prolog that prevented the 
    use of alternative compilation directories (i.e. turning on the "altdirs" 
    compiler flag). Corrected a bug when running Logtalk with SWI-Prolog that 
    can prevent make/0 from recompiling and reloading modified Logtalk source 
    files. Updated the SWI-Prolog integration script, "swilgt.sh", to more 
    reliably detect the compiler executable name.

    Added a "configs/swi_set_logtalk_context.pl" file defining a useful but 
    fragile hack implementing a set_logtalk_context/1 built-in predicate for 
    switching the Logtalk top-level execution context to objects other than 
    the default pseudo-object "user" (you may use it as a debugging tool).

    Updated the CxProlog config file to use the new built-in predicates in 
    version 0.95. Added a shell script, "cxlgt.sh", for easy integration of 
    Logtalk with CxProlog on POSIX systems (with the help of Artur Miguel 
    Dias, CxProlog author).

    Updated the Ciao, K-Prolog, and ECLiPSe config files to set the default 
    value for the compiler flag "underscore_vars" to "dont_care" in order to 
    avoid spurious warnings with some of the provided examples.

    Added a config file and integration scripts for the current XSB CVS 
    version (3.0.1+), which supports some features needed by Logtalk not 
    present in the current stable version (namely, expansion of environment 
    variables).

    Added predicates depth/2 and variant/2 to the library object "term".

    Much improved "benchmarks" example, updated to allow running tests in 
    three different scenarios: event support on, event support off, and 
    using static binding. Moreover, metacalls are no longer used to run 
    the benchmark goals, resulting in more meaningful and accurate results.

    Removed all the "make_*lgt.*" and "makeall_lgt.*" shell scripts, replaced 
    by pre-made integration scripts that can be found on the new "integration"
    directory. Removed the "lgt_install.js" script. Renamed the POSIX install 
    and uninstall scripts to, respectively, "install.sh" and "uninstall.sh".
    Updated the integration, uninstall, and user-setup POSIX shell scripts 
    to use "$prefix/share/logtalk" as the default installation directory to 
    better comply with the Filesystem Hierarchy Standard 2.3 for UNIX-like 
    operating systems.

    Updated the integration scripts to automatically call the "cplgtdirs" 
    script when the Logtalk user directory cannot be located.

    Updated the integration, documentation, uninstall, and user-setup POSIX 
    shell scripts to try to locate the Logtalk installation directory and the 
    Logtalk user directory when the environment variables LOGTALKHOME and 
    LOGTALKUSER are not set.

    Updated the "install.sh" POSIX shell script to better clean and sanitize 
    the file permissions on the installation directory.

    Updated the "build_release.sh" POSIX shell script to also build a Debian 
    binary installer package (experimental).

    The Windows GUI installer no longer spans command-line shells running 
    JScript scripts to build the Prolog integration shortcuts. This hopefully 
    solves issues with security software silently blocking and breaking the 
    Logtalk installation.

    Added basic syntax coloring support for the GNU Nano 2.x text editor.


2.29.5 - March 28, 2007

    Added a new built-in predicate, threaded/1, for proving each goal in 
    a conjunction in its own thread, simplifying common multi-threading 
    tasks that previously required sequences of calls to the built-in 
    predicates threaded_call/1 and threaded_exit/1.

    Simplified and optimized the implementation of Logtalk multi-threading 
    support.

    Simplified implementation of the database built-in methods. Simplified 
    caching of dynamic predicate lookups. Improved performance of the 
    built-in methods retract/1 and retractall/1.

    Simplified the code generated when compiling entities in debugging mode.

    Corrected a bug in the built-in debugger when processing actions at a 
    port that implies reading a port action again (e.g. print exception term,
    print debugging status, and help options). Allow the debugger command 
    "skip" to work as the command "creep" in ports other than "call" and 
    "redo". Added a new debugger command, "ignore". Suspend debugging when 
    using the "break" debugger command.

    Generate a compilation error instead of just printing a warning when 
    compiling calls to the multi-threading built-in predicates within an 
    object with no threaded/0 directive present.

    Corrected a bug when compiling entities containing synchronization 
    directives on single-threaded Prolog configurations.

    Improving reporting of working directory when loading or compiling source 
    files by expanding any environment variables occurring in the path.

    Added a new compiler option, "reload", for defining the Logtalk behavior 
    when reloading source files. Valid values are "always" (default value; 
    defined in the config files) and "skip".

    Updated the programming examples to use the new "reload" compiler option 
    when loading library entities. Simplified loading of example source files 
    (by updating the utility loader files to automatically load all required 
    library files).

    Updated GNU Prolog config file to take advantage of some built-in list 
    predicates (requires version 1.2.14 or later); changed the compiler flag 
    "underscore_vars" value to "dont_care" to avoid spurious warnings with 
    some examples.

    Added a config file for B-Prolog 7.0b1.

    Updated the POSIX integration shell scripts to pass along any command 
    line options to the corresponding Prolog compiler and to prevent some 
    problems with paths containing spaces.

    Much improved syntax coloring and code completion support for the jEdit 
    text editor.

    Updated the "threads/primes" example to use the new "threaded/1" built-in 
    predicate. Updated the "threads/birthdays" example to better illustrate 
    the use of the built-in multi-threading predicates. Added a new 
    multi-threading example, "msort", implementing single-threaded and 
    multi-threaded versions of the merge sort algorithm.

    Expanded the "operators" example to illustrate a simple solution for 
    making operators local to source files (but global to all entities 
    defined within the source files).


2.29.4 - February 19, 2007

    Added a new library category, "listing", defining listing/0 and 
    listing/1 methods for helping in debugging tasks.

    Added two new experimental multi-threading predicates, threaded_wait/1 
    and threaded_notify/1, which allows suspension of a thread's goal until  
    a notification is received. Added two new examples, "threads/buffer" and 
    "threads/blackboard", illustrating the use of these predicates.

    Simplified and changed implementation of the threaded built-in 
    predicates in order to ensure that the threaded/0 directive is only 
    required on objects calling these predicates.

    Only print a warning for a missing threaded/0 directive for objects.

    Corrected a ordering bug on the entity initialization goal that 
    prevented using an object initialization goal that make use of 
    the object thread. 

    Corrected a bug when asserting rules into an object's database that 
    resulted in only the first asserted rule being visible when calling 
    the predicate through message sending. Thanks to Parker Jones for 
    the bug report.

    Corrected a bug when compiling dynamic entities (defined in source 
    files using the dynamic/0 directive) where declared predicates would 
    be wrongly compiled as static instead of dynamic.

    Updated the "make_xsblgt.sh" integration script again to fix an 
    additional problem resulting from the lack of support in XSB for 
    using environment variables in file paths.

    Added minimal support for using Exuberant Ctags with Logtalk.

    Added auto indent support to the jEdit text editor.

    Added support for listing public predicates in the "Functions" window 
    of the SuperEdi text editor.

    Converted TextMate code snippets from the old Property List format 
    to XML in order to provide compatibility with the "e" Windows text
    editor.

    New example: 99 bottles of beer on the wall! Sing along!


2.29.3 - January 15, 2007

    Corrected a bug in the Logtalk compiler optimizer code which was 
    discarding some declaration and definition catchall clauses needed 
    by the Logtalk built-in database methods when there is no initial 
    declaration and definition for the referenced dynamic predicates.
    Thanks to Parker Jones for the bug report.

    Corrected a bug in the compilation of empty, standalone protocols 
    and categories.

    Updated the "make_xsblgt.sh" integration script to workaround 
    the lack of support in XSB for using environment variables in 
    the argument of the reconsult/1 predicate.

    Corrected a bug in the "potions.lgt" example puzzle that prevented 
    its solution of being found.


2.29.2 - January 10, 2007

    Silently compile synchronized predicates as normal predicates on 
    single-threaded Prolog compilers.

    When using the threaded_race/1 predicate, competing threads are 
    now created detached.

    Corrected a bug that resulted in a loading error when reloading 
    source files defining threaded objects.

    Corrected a bug in the implementation of the built-in predicate 
    threaded_peek/1 that prevented alternative solutions from being 
    retrieved using the built-in predicate threaded_exit/1. Removed 
    the built-in predicate threaded_discard/1.

    The library object "random" is now a synchronized object. Updated 
    the "philosophers" multi-threading example accordingly.

    Dropped loading of broken "cleanup" library from the YAP config file 
    (the call_cleanup/2 predicate, required for Logtalk multi-threading, 
    is now available as a built-in predicate in the YAP CVS version).


2.29.1 - December 28, 2006

    Added a Logtalk version of John Fletcher's Prolog XML parser (see the 
    folder "contributions/xml_parser").

    Added shell scripts for helping building the distribution files of a 
    new Logtalk release. Updated the MacOS X installer package to set 
    default values for the Logtalk environment variables. Corrected a bug 
    in the "logtalk.spec" file where the default value for the LOGTALKUSER 
    environment variable only worked for the user doing the RPM installation.

    Corrected a bug in the reporting of the line number where a compilation 
    error (or warning) occurred. Extended support for reporting warning and 
    error line numbers to Quintus Prolog, Ciao Prolog, Qu-Prolog, and 
    ECLiPSe.

    Corrected a bug when using partial lists with the predicates nth0/3-4 
    and nth1/3-4 provided by the "list" library object.

    Improved "philosophers" multi-threading programming example.


2.29.0 - December 18, 2006

    Added a new built-in, empty object named "logtalk", which can play the 
    role of both a class and a prototype. It may be used to define class 
    hierarchies without forcing the use of metaclasses or reflective 
    designs.

    Added a built-in protocol named "monitoring" with declarations for 
    the before/3 and after/3 public event handler predicates. Updated 
    the Logtalk compiler to print a warning when defining an event handler 
    with no reference to the "monitoring" protocol.

    The default value of the compiler flag events/1 is now off. As most 
    applications do not use events, this setting ensures the best possible 
    message processing performance for those applications.

    Removed the experimental threaded_call/2 and threaded_exit/2 thread 
    predicates, replaced by new threaded_once/1, threaded_ignore/1, 
    threaded_race/1, threaded_peek/1, and threaded_discard/1 predicates.
    Renamed predicate directive atomic/1 to synchronized/1. Added new 
    entity directive synchronized/0. Added support for new "synchronized" 
    and "threaded" entity properties.

    Corrected a bug when using threaded calls as initialization goals 
    within threaded objects.

    Corrected an elusive bug in the Logtalk compiler where a source file 
    may not be properly closed when it contains a syntax error (thanks 
    to Robert Shiplett for the bug report).

    Corrected a bug in the implementation of the built-in methods retract/1 
    and retractall/1 that could result in unexpected exceptions. Updated 
    the built-in method assertz/1 to always use the lookup cache.

    Corrected a bug in the compilation of empty classes that are not 
    instances of a metaclass.

    Corrected a bug in the built-in method predicate_property/2 where some 
    predicate properties may not be returned when enumerating properties 
    using backtracking.

    Modified the SWI-Prolog config file and integration scripts to set 
    the flag "iso" to "true". Corrected an elusive bug in the definition 
    of predicate '$lgt_directory_exists'/1 that resulted in "library not 
    found" errors when loading Logtalk source files from within the