Logtalk 2.34.0 released

[Paulo Moura]

Hi!

Logtalk 2.34.0 is now available for downloading. This release adds support for conditional compilation in source files, improves term and goal expansion mechanisms, adds a new compiler flag for identifying back-end Prolog compilers, corrects some minor bugs, and includes new and improved programming examples.

Upgrading from previous release:

* The config files from previous releases are incompatible with this new version. The config files extension is now .pl instead of .config and there is also a new compiler flag, "prolog", defined in the config files.

Known compatibility issues:

* YAP: multi-threading support is currently broken. No timeframe for fixing the current bugs. Use YAP single-threaded version until the bugs are fixed.
* XSB (CVS version): some bugs in multi-threading support prevent some thread examples from running.
* Ciao: support for multifile/1 predicate directives is broken. No reply so far to my bug report to the Ciao developers.

Follows the detailed release notes:

* Added conditional compilation support, as found in some Prolog compilers, using the new directives if/1, elif/1, else/0, and endif/0. The arguments of the if/1 and elif/1 directives are subjected to goal expansion.

* Added a "prolog" read-only compiler flag whose value is the name of the back-end Prolog compiler (an atom). This flag can be used for conditional compilation of Prolog specific code.

* Added an expand_goal/2 built-in method to support explicit calls to the goal_expansion/2 user-defined hook. Updated the term expansion mechanism to allow the expansion to be a single term instead of a list of terms. Improved the documentation of the term and goal expansion predicates.

* Simplified the implementation of the threaded/1 built-in predicate.

* Removed support for the deprecated message_queue_create/1 Prolog built-in predicate.

* Corrected a bug in the implementation of the predicate_property/2 built-in method which would return wrong meta-predicate templates for predicate aliases.

* Corrected a bug in the compilation of meta-calls to predicates defined in the pseudo-object "user".

* Corrected a bug that prevented goal expansion of source file initialization goals (expressed using the initialization/1 directive).

* Modified the "statistics" library to use the variance numerically stable algorithm to calculate accurate values for the standard deviation for both samples and populations. Thanks to Parker Jones for the bug report. Added calculation of sample and population kurtosis.

* Added predicates included/3, excluded/3, fold_left/4, and fold_right/4 to the library entities "metap" and "meta" (requested by Paul Crocker). Renamed the predicates filter/3 and succeeds/2 to included/3 and map/2, respectively (the older names are still available using aliases defined in "meta").

* Changed the file name extension of all config "*.config" files to "*.pl". Changed the file name extension of all library "*.notes" files to "*.txt".

* Updated the "metapredicates" example with Paul Crocker's contributions to illustrate the use of some of the meta-predicates implemented in the Logtalk library.

* Updated the "expansion" example to illustrate the new expand_goal/2 built-in method. Improved example documentation.

* Added an example, "cc", of using conditional compilation directives to implement a portable operating-system interface for selected back-end Prolog compilers.

* Added an example, "prototypes", illustrating the concept of "prototype".

* Added syntax coloring support for the new expand_goal/2 method and for the if/1, elif/1, else/0, endif/0, set_logtalk_flag/2, ensure_loaded/1 and, set_prolog_flag/2 directives to the supported text editors and syntax highlighters.

* Fixed a block comment syntax coloring bug in the support for the Highlight syntax highlighter with the help of André Simon.

Happy logtalking!

Paulo