Ahh, the Law of Demeter - thanks for throwing that one into the conversation :O)
I went to Google to get a good reference to the LoD to post here for those unfamiliar with it and found this (http://www.ccs.neu.edu/home/lieber/LoD.html) which includes a neat tidbit on the LoD at the Jet Propulsion Lab; in particular I was intrigued by the costs associated with the Non-LoD portions of their system. >From [EMAIL PROTECTED] Mon May 26 17:33:30 1997 >From: "David E. Smyth" >To: [EMAIL PROTECTED] >Subject: Law of Demeter > >I have been using LoD pervasively since about 1990, and it has taken >firm hold in many areas of the Jet Propulsion Laboratory. Major systems >which have used LoD extensively include the Telemetry Delivery System (a >real-time database begun in 1990), the Flight System Testbed, and Mars >Pathfinder flight software (both begun in 1993). We are going to use LoD >as a foundational software engineering principle for the X2000 Europa >orbiter mission. I also used it within a couple of commercial systems >for Siemens in 91-93, including a Lotus Notes like system, and a email >system. ... > We have found, however, that breaking the LoD is very expensive! On > Mars Pathfinder, the integration costs of the law breaking parts of > the system were at least an order of magnitude higher, and we had > to pay that cost on every integration cycle -- not just once! We > should have paid the cost once by implementing a more sophisticated > protocol that did obey the LoD. ---------------------------------------------------------- You are subscribed to cfcdev. To unsubscribe, send an email to [email protected] with the words 'unsubscribe cfcdev' as the subject of the email. CFCDev is run by CFCZone (www.cfczone.org) and supported by CFXHosting (www.cfxhosting.com). CFCDev is supported by New Atlanta, makers of BlueDragon http://www.newatlanta.com/products/bluedragon/index.cfm An archive of the CFCDev list is available at www.mail-archive.com/[email protected]
