Does functional programming work?

[bearophile]

grauzone:
> That's all gone in modern Pascal dialects. Delphi is very similar to D; 
> it's practically a Pascal version of D. The OOP features are the same, 
> except for some small differences, which make Delphi a bit more flexible 
> (virtual and named constructors...).

And as you know, C# was partially designed by the same people :-)

About Delphi virtual constructors:
http://www.felix-colibri.com/papers/oop_components/delphi_virtual_constructor/delphi_virtual_constructor.html

About Delphi named constructors:
http://stackoverflow.com/questions/1758917/delphi-pascal-overloading-a-constructor-with-a-different-prototype/1759217#1759217

In Table 2-1 shows a list of some Delphi features:
http://oreilly.com/catalog/delphi/chapter/ch02.html
Beside virtual methods there are dynamic methods too, that are unrelated to dynamic methods of C#:
>Instead of using the virtual directive, you can also use the dynamic directive. The semantics are identical, but the implementation is different. Looking up a virtual method in a VMT is fast because the compiler generates an index directly into a VMT. Looking up a dynamic method is slower. Calling a dynamic method requires a linear search of a class's dynamic method table (DMT). If the class does not override that method, the search continues with the DMT of the base class. The search continues with ancestor classes until TObject is reached or the method is found. The tradeoff is that in a few circumstances, dynamic methods take up less memory than virtual methods. Unless you are writing a replacement for the VCL, you should use virtual methods, not dynamic methods. See Chapter 3 for a complete explanation of how dynamic and virtual methods are implemented.<


There are even metaclasses (from the same document):
>A class, too, is a distinct entity (as in Java, but unlike C++). Delphi's representation of a class is a read-only table of pointers to virtual methods and lots of information about the class. A class reference is a pointer to the table. (Chapter 3, Runtime Type Information, describes in depth the layout of the class tables.) The most common use for a class reference is to create objects or to test the type of an object reference, but you can use class references in many other situations, including passing class references as routine parameters or returning a class reference from a function. The type of a class reference is called a metaclass.<

In C++/D to do something similar to metaclasses you use templates:
http://marcin.wudarczyk.pl/education/tipstricks/metacls.htm


> The only thing that was really lacking in Delphi are templates. But for 
> compensation, it had powerful RTTI.

About Delphi RTTI, this document is not new (it seems updated to Delphi 4, that's a bit ancient) but it looks well written:
http://www.blong.com/Conferences/BorConUK98/DelphiRTTI/CB140.htm

Bye,
bearophile