================================================================= Logtalk - Object oriented extension to Prolog Release 2.22.1 Copyright (c) 1998-2004 Paulo Moura. All Rights Reserved. ================================================================= This folder contains several examples of Logtalk programs. A brief description of each example is included below. Each example folder contains a NOTES file and a loader helper file which may be used to load all the example entities. In addition, most examples contain a SCRIPT file with instructions on how to load the example and sample queries for your to try. Most of these examples need objects, protocols, and categories which are defined in the Logtalk standard library or in other examples. See the NOTES files inside the library folder and the NOTES and SCRIPT files inside each example folder). Some examples may redefine objects already loaded from other examples. You may want to restart Logtalk after trying each example. Some of the examples code have been adopted from public available Prolog code and from known Prolog text books and are copyrighted by the respective authors. These are programming examples, meaning that you should study the source files to fully understand them. All examples are formatted using four spaces tabs. By default, compiling an example generates a .xml documenting file for each compiled entity (object, category, or protocol). See the xml folder for instructions on how to browse the .xml files for on-line reading or how to convert the files to a print-ready format such as PDF. Here is a short description of each included example: aliases example of using the alias/3 predicate directive to provide alternative names to inherited predicates in order to improve readability benchmarks simple benchmarks for for helping measuring performance of Logtalk message seding between Prolog compilers and for comparing message sending with predicate calls in plain Prolog and with calls to modules predicates birds bird identification expert system example adopted from the Adventure in Prolog Amzi! book bricks example of representation and handling of relations using events classvars example of implementation of class variables (as found in Smalltalk) dcgs examples of using DCG rules inside objects and categories diamonds examples of problems and solutions for the "diamond problem" (multi-inheritance conflicts and ambiguities) dynpred example of using some of the built-in database handling methods engines example of category composition (importation of categories by other categories) using car engines errors example showing the Logtalk compiler warning and error reporting hello_world the unavoidable hello world programming example inheritance examples of public, protected and private inheritance with both prototypes and classes/instances instmethods example of instance defined methods lo examples adopted from the Francis G. McCabe L&O system logic example of a translator of logic propositions to clauses in conjunctive normal form lpa examples adopted from the LPA Prolog++ system metapredicates example of using metapredicates in Logtalk objects metainterpreters some examples of simple metainterpreters mi multi-inheritance examples miscellaneous unsorted examples msglog example of using events and monitors for recording, replaying, and printing user messages operators example of using operators local to objects and categories parametric simple example of parametric objects poem examples adopted from the Ben Staveley-Taylor POEM system points example adopted from SICStus Objects documentation polygons example of representation and handling of relations using events profiling examples of using of events and monitors to implement profilers puzzles several examples of logical puzzles reflection example of a simple class-based reflective system relations objects implementing predicates for dealing with relations and constrained relations between objects roots objects, protocols and categories needed by most of the other examples searching state-space searching framework example adopted from Ivan Bratko's "Prolog Programming for Artificial Intelligence" book shapes geometric shapes implemented as both a prototype hierarchy and a class hierarchy sicstus examples adopted from SICStus Objects documentation symdiff example of using parametric objects to implement symbolic expression differentiation and simplification viewpoints example on how to implement property and value sharing with prototypes