Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!utgpu!water!watmath!clyde!rutgers!seismo!mcvax!enea!suadb!anders From: anders@suadb.UUCP Newsgroups: comp.lang.smalltalk Subject: Re: Messages? Message-ID: <283@suadb.UUCP> Date: Fri, 5-Jun-87 09:12:46 EDT Article-I.D.: suadb.283 Posted: Fri Jun 5 09:12:46 1987 Date-Received: Sun, 7-Jun-87 10:26:36 EDT References: <572@tragicomix.liu.se> <574@tragicomix.liu.se> Reply-To: anders@suadb.UUCP (Anders Bj|rnerstedt) Organization: University of Stockholm, Sweden Lines: 38 In article gorry@tragicomix.liu.se (Goran Rydquist) writes: >Anyone know how the lookup of the messages are done in a normal >implementation of Smalltalk, or any other OO language? > >Although the concept of inheritance is very powerful, it is clearly >associated with overhead from running around hierarchies to find >methods. Couldn't that processing overhead be traded against memory? >The inheritance concept should preferably not be thrown away, but kept >conceptually. Any ideas? > >gorr\/ gorry@majestix.liu.se > / Inheritance as such is not the cause of overhead. Dynamic binding of methods is. Simula for example has inheritance, but resolves "method" binding at compile time (except for virtual procedures). Another common misunderstanding is that strong typing and late binding are mutually exclusive. The virtual procedures of Simula provide both strong typing and late binding. --------------------- Anders Bjornerstedt Department of Information Processing & Computer Science University of Stockholm S-106 91 Stockholm Sweden UUCP:{seismo,mcvax,cernvax,diku,ircam,prlb2,tut,ukc}!enea!suadb!anders ARPA: enea!suadb!anders@seismo.arpa