Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!seismo!mcvax!ukc!eagle!icdoc!cam-cl!scc From: scc@cl.cam.ac.uk (Stephen Crawley) Newsgroups: comp.lang.misc Subject: Re: Mesa vs Modula-2 (and CLU) Message-ID: <1039@jenny.cl.cam.ac.uk> Date: Wed, 5-Aug-87 19:14:44 EDT Article-I.D.: jenny.1039 Posted: Wed Aug 5 19:14:44 1987 Date-Received: Sun, 9-Aug-87 10:17:33 EDT References: <415@unisoft.UUCP> Reply-To: scc@cl.cam.ac.uk (Stephen Crawley) Organization: U of Cambridge Comp Lab, UK Lines: 34 Keywords: Mesa Modula-2 CLU In article <1246@ius2.cs.cmu.edu> ralphw@ius2.cs.cmu.edu (Ralph Hyre) writes: >I've heard some say that Modula-2 is a Mesa rip-off, since Wirth spent >a year sabbatical at Xerox Parc. That's what I heard too. Modula-2 is Mesa with the good bits left out (:-) > I prefer CLU myself. [Please note: I've never written anything other than toy programs in CLU, so I can't talk with any authority.] CLU has a lot going for it. It is generally a cleaner, better designed language than Mesa. It also language has features that I miss in Mesa ... abstract data types, type parameters and garbage collection spring to mind as being important. On the minus side (compared with Mesa), CLU has no support for concurrency and it is exceedingly difficult to do low level register poking and pointer bashing in CLU [can you say "CLU compatible assembler"?]. In my case, the decision to go for Mesa rather than CLU was motivated by pragmatic considerations. The CLU linker is painfully slow, and the CLU/UNIX runtime environment is sparse compared to Mesa/XDE. I was (and still am) keen on an open OS environment with light-weight processes and dynamic loading of code. Address space firewalls (like between 2 UNIX processes!) are a pain in my line of work. That having been said, if I were to make the choice today with the benefit of hindsight, I think it might well go the other way. The reason is that I find that most of the problems in my work (persistent object management) are due to Mesa having no garbage collection. When I changed to Mesa a couple of years ago, I thought that GC was a no-no for OS type work because of the performance implications. I've since changed my mind. -- Steve