[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] how much complexity is unavoidable?
Over the weekend, I spent some time reading through Xalan documentation and some of its sources. The complexity of the javaDoc baffled me. I mean I understand XSLT is complex and optimizing it even more so, and I didn't expect to understand all of the code in one sitting. I was hoping to understand *how difficult* would it be to adapt its internal data model to nonstandard use. But the number of packages, classes, class members and the deep inheritance hierarchies made the docs difficult to navigate. The "plain" docs had a number of interesting insights. In particular, the design document [1] says: The main goals of this redesign are to: 1.Make the design and code more understandable by Open Source people. I paused for a while when I read that. And then I decided to see what "open source people" thought to be "more understandable". Here's an observation: [kari@pc-kari kari]$ du -sh $XSLT_SOURCES 9.3M xalan-j_2_4_0/src/org/apache 2.8M saxon6_5_2/source/com/icl/saxon 1.6M xt-20020426a-src/src/com/jclark There are two issues with this that I could immediately think of: (1)XT is incomplete, missing some minor feature which Xalan is reported to support. (2)Xalan includes xsltc, an XSLT-to-Java-bytecode compiler; OTOH, both XT and Saxon include their own parsers, whereas Xalan relies on Xerces (not included in the estimate). Could there be a drastic difference in complexity, for the same functionality, depending on the vendor's size? Is it possible that similar trends exist in specifications as well as implementations? Ari. [1] http://xml.apache.org/xalan-j/design/design2_0_0.html#intro -- "Einstein repeatedly argued that there must be simplified explanations of nature, because God is not capricious or arbitrary. No such faith comforts the software engineer. Much of the complexity that he must master is arbitrary complexity, forced without rhyme or reason by the many human institutions and systems to which his interfaces must conform." Fred Brooks, "No Silver Bullet", 1986
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