RE: [PEAR-DEV] New XSLT class for PEAR

I'll keep that mail and reread more carefully ;)) Thanks for the exlanation, i'll dig into that. Arnaud. > I'll have a go. Flames to /dev/null please ;-) > > A stateful object is basically an object with memory. An > object where you > get/set values that are stored within the object. This is > fine (imho) when > your object is encapsulating a piece of data - such as a > string, a file, a > XML document, and so on. Can't really have it any other way. > > On the other hand, another type of object is one that *does* > something to > datatypes. A XSLT Processor is an excellent example. The > processor takes > two (sometimes three ;-) inputs - XML, XSLT, and an optional set of > parameters - does something - and produces an output. You'd > expect to be > able to use and re-use the processor over and over again. > This type of > object (imho) has no need whatsoever to be stateful. I'd go as far as > saying that it's poor quality engineering. > > The reason I'm not comfortable with objects being unnecessary > stateful has > to do with quality. Stateful code - of any description - is > non-deterministic, and more prone to bugs. This is > especially true over > time when many engineers work on the code. Non-stateful > code, on the other > hand, is deterministic. Same input - same output. You can > write unit tests > that are more simple, and require less maintenance over time. > Given that > any comprehensive set of unit tests will take up between 30% > and 50% of > total development time, that's very important ;-) > > That's what I mean. > > Best regards, > Stu > -- > >