I have written/test a couple of trivial module servlets and Robby you are correct - module servlets can be un/load without problems and the error doesn't seem to affect the servers.  So from what I can tell there are no discernible differences, perhaps until I run into very complex scenarios.  Thanks! yinso <div>On 4/11/07, Robby Findler <<a href="mailto:robby@cs.uchicago.edu">robby@cs.uchicago.edu</a>> wrote:<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> On 4/11/07, Yin-So Chen <<a href="mailto:yinso.chen@gmail.com">yinso.chen@gmail.com</a>> wrote: > Really?!  Not being familiar with the history of PLT scheme I have to say I > am surprised by the answer - I would have thought module is an older > concept.  Sounds like you are saying unit is slowly fading away? Oh, no! I wouldn't say that. It was just that, in the past, unit was our top-level program structure, but we soon realized that units work better as a general tool for constructing programs and we needed a more first-order construct for just defining the top-level program structure (in order to make compilation more tractable, etc). I'm using "we" in the loosest possible sense here. It was Scott Owens and Matthew Flatt who really nailed down the difference and explained it properly. Probably they can point you to some writings or say more about it. > Can module based servlets be loaded/unloaded on demand like unit-based > servlets?  And would badly written module servlet bring down the server? > Unit servlets appear to handle the above fine, but if module servlet also > works, then I am not sure if there are discernible differences (although > there are still more unit-servlet examples in the doc). I think these questions are all answered the same way, regardless of whether or not you use a module servlet or a unit servlet. I should probably defer to Jay, tho. There may be some issues I'm not up to speed with in the web server. Robby > Thanks, > yinso > > > On 4/11/07, Robby Findler <<a href="mailto:robby@cs.uchicago.edu">robby@cs.uchicago.edu</a>> wrote: > > I suspect that most everyone wants to use module servlets these days, > > not unit servlets. Once upon a time, we didn't have modules (and > > servlets existed at that time), so we used units. Nowadays, modules > > work much better with all of our other tools (like the compiler, for > > example, but also the module browser and things like that), that you > > really want your program to be in a module. > > > > That said, of course, if your program calls for the power of units, > > use the units inside the module! > > > > Robby > > > > On 4/11/07, Yin-So Chen <<a href="mailto:yinso.chen@gmail.com">yinso.chen@gmail.com</a>> wrote: > > > Hi all - > > > > > > yet another newbie question - what is the difference between unit-based > > > servlet and module-based servlet and when to choose which?  Are the two > > > comparable in terms of capabilities?  I look at the unit doc and notices > > > that it is analogous to a pluggable component and hence appears to have > more > > > flexibility and power than module, so was wondering under what > situations > > > would a module servlet be preferrable over a unit servlet. > > > > > > Thanks, > > > yinso > > > > > > -- > > > <a href="http://www.yinsochen.com">http://www.yinsochen.com</a> > > > ...continuous learning... > > > _________________________________________________ > > >   For list-related administrative tasks: > > >   <a href="http://list.cs.brown.edu/mailman/listinfo/plt-scheme">http://list.cs.brown.edu/mailman/listinfo/plt-scheme </a> > > > > > > > > > > > > -- > > <a href="http://www.yinsochen.com">http://www.yinsochen.com</a> > ...continuous learning... </blockquote></div> -- <a href="http://www.yinsochen.com">http://www.yinsochen.com</a> ...continuous learning...