Functional programming: Examples, Methods and Concepts

In computer science, functional programming is a programming paradigm that treats computation as the evaluation of mathematical functions and avoids state and mutable data. It emphasizes the application of functions, in contrast with the imperative programming style that emphasizes changes in state.

The lambda calculus provides the model for functional programming. Modern functional languages can be viewed as embellishments to the lambda calculus.

While not fully functional, both the original Lisp and APL were important in the development of functional programming. Later versions of Lisp such as Scheme and variants of APL did provide full functional support. Other important functional languages include Erlang, Haskell, and ML.

Central Authentication Service – CAS: concepts and examples

The Central Authentication Service (CAS) is a single sign-on protocol for the web. Its purpose is to permit a user to log into multiple applications simultaneously and automatically. It also allows untrusted web applications to authenticate users without gaining access to a user’s security credentials, such as a password. The name CAS also refers to a software package that implements this protocol.

The Central Authentication Server (CAS) is designed as a standalone web application. It is currently implemented as several Java servlets and runs through the HTTPS server on secure.its.yale.edu. It is accessed through three URLs described below: the login URL, the validation URL, and the optional logout URL.

Swing Application Framework (JSR-296): new concepts, new features

Swing is a widget toolkit for Java. It is part of Sun Microsystems’ Java Foundation Classes (JFC) — an API for providing a graphical user interface (GUI) for Java programs.

Swing was developed to provide a more sophisticated set of GUI components than the earlier Abstract Window Toolkit. Swing provides a native look and feel that emulates the look and feel of several platforms, and also supports a pluggable look and feel that allows applications to have a look and feel unrelated to the underlying platform.

Zend Framework – ZF: Concepts, Methods and Examples

Zend Framework is an open source, object-oriented web application framework implemented in PHP 5 and licensed under the New BSD License. Zend Framework—often referred to as ZF—is developed with the goal of simplifying web development while promoting best practices in the PHP developer community.
ZF’s use-at-will architecture allows developers to reuse components when and where they make sense in their applications without requiring other ZF components beyond minimal dependencies. There is therefore no single development paradigm or pattern that all Zend Framework users must follow, although ZF does provide components for the MVC and Table Gateway design patterns which are used in most ZF applications. Zend Framework provides individual components for many other common requirements in web application development, including authentication and authorization via access control lists (ACL), application configuration, data caching, filtering/validation of user-provided data for security and data integrity, internationalization, interfaces to AJAX functionality, email composition/delivery, Lucene-format search indexing and querying, and all Google Data APIs along with many other popular web services. Because of their loosely coupled design, ZF components can be used relatively easy alongside components from other PHP web application frameworks.