<ajb@spamcop.net> wrote in message news:20060119185325.iw9di8gwcc0kkkgw@webmail.spamcop.net...
G'day all.
Quoting Benjamin Franksen <benjamin.franksen@bessy.de>:
However, not everyone in the OO camp thinks that UML is really useful:
http://archive.eiffel.com/doc/manuals/technology/bmarticles/uml/page.html
Having actually used it (once), the consensus seems to be:
1. It only applies to a "pure" OO style. Just about all useful programming languages for programming-in-the-large (Haskell included) are multi-paradigm.
2. It's difficult to refactor. This makes it useless for design purposes, especially if your development development methodology is sufficiently agile.
The upshot is that UML's only use is for docmentation after the fact, or for Big Design Up Front projects. But only if you use a strict subset of what most programming languages give you. I am no rabid UML fan, but I am reasonably familiar with it, and I have to say this is garbage. UML class diagrams are invaluable both for the conceptual analysis and design work as well as for after the fact overview of the class structure. State models are essential for designing the behavior of interesting objects. Slightly less important (IMHO) but still useful are acitivity charts (for use case flow), and interaction diagrams (although I have found them personally less useful for the initial conceptualization. I have found them more useful for explaining method interactions to someone). The fact that highly popular tools like TogetherJ put a lot of effort into recovering the class diagram and the interaction diagram from code should be some indication of their importance and usefulness. In addition, the latest MDA model compilers can generate entire applications from UML models. Some documentation that is!
I have personally noticed less of a need for modeling tools with Haskell b/c the language itself is fairly abstract, but also because i tend not to write stateful, structurally rich applications in Haskell. If the next version of Haskell does support a more convenient and extensible datatype mechanism, then i can see people using Haskell for such applications and therefore a need for some kind of diagrammatic modeling tool there too. cheers -s