9.3. A General Model for Maintainable Perl Programs

Set aside all the wisecracks about Perl being unmaintainable or useful only for small scripts. Also be prepared to renounce the widely held assumption that it's not a truly object-oriented language. In this section we will develop a general Perl framework that will let you quickly add new features to applications and adapt applications to changing database structures.

The code that follows is complex and requires an in-depth knowledge of Perl. Among the features of Perl we exploit are references, recursion, variable type checking, function argument manipulation (the $_[0] syntax), dynamic array building through push statements, and multidimensional hashes—and of course, lots of object-oriented techniques. These features are amply explained in other Perl books, notably Programming Perl by Larry Wall, Tom Christiansen, and Jon Orwant (O'Reilly).