User Manual

Logtalk features

• Integration of logic and object-oriented programming
• Integration of event-driven and object-oriented programming
• Support for both prototype and class-based systems
• Support for multiple object hierarchies
• Separation between interface and implementation
• Private, protected and public inheritance
• Private, protected and public object predicates
• Parametric objects
• Smooth learning curve
• Compatibility with most Prologs and the ISO standard

Message sending

• Operators used in message sending
• Sending a message to an object
• Broadcasting
• Sending a message to self
• Calling an overridden predicate definition
• Message sending and event generation

Objects

• Objects, prototypes, classes and instances
• Defining a new object
• Parametric objects
• Finding defined objects
• Creating a new object in runtime
• Abolishing an existing object
• Object directives
Object initialization
Dynamic objects
Object dependencies
Object documentation
• Object relationships
• Object properties
• The pseudo-object user

Protocols

• Defining a new protocol
• Finding defined protocols
• Creating a new protocol in runtime
• Abolishing an existing protocol
• Protocol directives
Protocol initialization
Dynamic protocols
Protocol documentation
• Protocol relationships
• Protocol properties
• Implementing protocols

Categories

• Defining a new category
• Finding defined categories
• Creating a new category in runtime
• Abolishing an existing category
• Category directives
Category initialization
Dynamic categories
Category dependencies
Category documentation
• Category relationships
• Category properties
• Importing categories

Predicates

• Declaring predicate
Scope directives
Mode directive
Metapredicate directive
Discontiguous directive
Dynamic directive
Operator directive
Documenting directive
• Defining predicates
Object predicates
Category predicates
• Built-in object predicates (methods)
Local methods
Database methods
All solutions methods
Reflection methods
• Predicate properties
• Finding declared predicates

Inheritance

• Protocol inheritance
Search order for prototype hierarchies
Search order for class hierarchies
• Implementation inheritance
Search order for prototype hierarchies
Search order for class hierarchies
Inheritance versus predicate redefinition
• Public, protected and private inheritance
• Composition versus multiple inheritance

Event-driven programming

• Definitions
Event
Monitor
• Event generation
• Communicating events to monitors
• Performance concerns
• Monitor semantics
• Activation order of monitors
• Event handling
Finding defined events
Defining new events
Abolishing defined events
Defining event handlers

Error handling

• Compiler warnings and errors
Unknown entities
Singleton variables
Redefinition of Prolog built-in predicates
Redefinition of Logtalk built-in predicates
Redefinition of Logtalk built-in methods
Misspell calls of local predicates
Portability warnings
Other warnings and errors
• Runtime errors
Logtalk built-in predicates
Logtalk built-in methods
Message sending

Documenting Logtalk programs

• Documenting directives
Entity directives
Predicate directives
• Processing and viewing documenting files

Configuring Logtalk

• Hardware & software requirements
Computer and operating system
Prolog compiler
• Configuration file contents

Installing and running Logtalk

• Installing Logtalk
Directories and files organization
Configuration files
Logtalk compiler and runtime
Library
Examples
Logtalk source files
Loader utility files
• Running a Logtalk session
Starting Logtalk
Compiling and loading your programs
Compiler option flags
Smart compilation of source files
• Using Logtalk for batch processing

Programming in Logtalk

• Logtalk scope
• Writing programs
Source files
Portable programs
Avoiding common errors