General Development Archive

Combining power with ease of use, the Rexx scripting language is enjoying a surge in popularity. Howard Fosdick introduces this free language and explores some of the basics you need to know before getting started. Elsewhere on that site, this chapter describes Python's built-in operators as well as the precedence rules used in the evaluation of expressions.

Algorithms can often be implemented recursively or nonrecursively; the decision rests with the programmer, who might shy away from a recursive solution because the algorithm might not terminate or that performance might be poor. In reality, recursion can allow for very elegant code as well as facilitating an interesting and economical type of code reuse. Software consultant Stephen B. Morris explores this interesting topic with a data-centric application drawn from the field of networking.

"I'm happy to announce today that ROTOR 2.0 has released to the web. You can download the release here. ROTOR contains most of the CLR and base class libraries found in our commerical product. It is released under the shared source program. There are several new things in this release: generics implementation; Lightweight Code Generation; stub-based dispatch support; new reflection and reflection emit; new C# features like Anonymous Methods, Anonymous Delegates and Generics."

"Recurring themes at this year's PyCON2006 Python conference, in Dallas, Texas, included quality control techniques for Python, and interoperable content management systems. Guido van Rossum presented some previews of features to be expected in Python 2.5, and Jim Fulton presented the 'State of Zope', with some musings on where to go from here with Zope 2 and Zope 3. Also starring at this conference was the S5 based on the Python docutils package - most of this year's talks were presented with this package, and one of the talks presented the S5 package itself."

It's all too easy to place operations code inside class definitions (that is, code that does create/delete/modify). In many cases, such an approach is not necessarily a reflection of real world objects. But there are other reasons for abstracting operation code. Stephen Morris spells out these and other advantages of using the command pattern.

"There are several possible reasons why you might choose to use the command line interface as your desktop environment. For one thing, it uses less electricity, so you could maximize battery life on your laptop computer. Secondly, it forces you to think about your operating system and directory structure in a totally different way than a GUI does; this could greatly enhance your understanding of GNU/Linux and cause you to be more creative in your technological problem solving. And thirdly, everyone will think you're a supreme computer genius for ditching X11 for the CLI. People passing by your desk will think you're some kind of computer god. Who doesn't want that?"