Path: news.daimi.aau.dk!news.uni-c.dk!sunic!sunic.sunet.se!columba.udac.uu.se!news.mdh.se!news.seinf.abb.se!eua.ericsson.se!erinews.ericsson.se!cnn.exu.ericsson.se!convex!cs.utexas.edu!howland.reston.ans.net!Germany.EU.net!nntp.gmd.de!news.rwth-aachen.de!news.rhrz.uni-bonn.de!news.uni-stuttgart.de!news.belwue.de!news.belwue.de!fu-berlin.de!zrz.TU-Berlin.DE!lise!wpp From: wpp@lise.physik.tu-berlin.de (Kai Petzke) Newsgroups: comp.lang.beta Subject: Re: Overriding procedural patterns Date: 24 May 95 15:26:32 GMT Organization: Technical University Berlin, Germany Lines: 41 Message-ID: References: <3o315c$9he@pulm1.accessone.com> <3odefd$hbp@belfort.daimi.aau.dk> <3otick$s3l@belfort.daimi.aau.dk> NNTP-Posting-Host: lise.physik.tu-berlin.de rws@daimi.aau.dk (Rene Wenzel Schmidt) writes: [discussion about override and OUTER snippped] >>I also think it should allow for an efficient implementation, even >>though it demands some changes compared to the methods used today in >>Mjølner BETA. Then again it might help in implementing virtual prefix >>and other as-yet-unsupported kinds of inheritance. >It is actually straight forward to implement and can also >be implemented very efficient. OUTER corresponds to C++'s A::B >syntax, so a similar implementation is possible. >It is statically know at compile-time what code the OUTER is >calling, so a direct jump-subrutine call can be generated. This >is in contrast to INNER where an indirect jump is needed. The >way INNER dispatch is handled through the INNER dispatch-table >does not need to be changed. This is true. However, the override operator again adds some complexity, as calling a pattern must then be done indirectly: in general, at compile time it is no longer known, which do-part has to be invocated first, thus the indirect call. But otherwise, I think of this as a good concept. As far, as I understand the override operator, it will override all the do parts on top of the pattern, that is defined with that operator. Would it also make sense to have an override operator, that overrides only a given number of do-Parts, or does that get too complex? Kai -- Kai Petzke | How fast can computers get? Technical University of Berlin | Berlin, Germany | Warp 9, of course, on Star Trek. wpp@marie.physik.tu-berlin.de |