From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=0.2 required=5.0 tests=BAYES_00,INVALID_MSGID, REPLYTO_WITHOUT_TO_CC autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: f66ab,c2ed41f6f9544612 X-Google-Attributes: gidf66ab,public X-Google-Thread: fa705,4e5700f5f17e49f4 X-Google-Attributes: gidfa705,public X-Google-Thread: 103376,18a09885d036772 X-Google-Attributes: gid103376,public From: vonhend@ibm.net Subject: Re: Is this ground dead? Also, info on Mach that's more recent Date: 1998/01/19 Message-ID: <34c39dc4.0@news1.ibm.net>#1/1 X-Deja-AN: 317413786 References: <34AE2AE8.ED17B2C6@gildea.net> <5lzpky66rq.fsf@tequila.systemsz.cs.yale.edu> <69jr4q$44j$1@encore.ece.cmu.edu> <69rdmb$j29$1@encore.ece.cmu.edu> Reply-To: vonhend@ibm.net Organization: IBM.NET Newsgroups: comp.os.mach,comp.unix.bsd.misc,comp.lang.ada Date: 1998-01-19T00:00:00+00:00 List-Id: In , dewar@merv.cs.nyu.edu (Robert Dewar) writes: > >Well if you look at chapter 13 and annex C in the RM, you wlil find lots >of useful stuff for writing low level code, Ada is (perhaps surprisingly >to some) better equipped for low level programming of this kind than C >(for example, the ability to lay out records precisely by bit numbers, >the ability to define interrupt routines, the ability to specify where >in memory declared variables are located etc). The C language has provided a syntax for bit fields since the late 70's. The disadvantage of C's syntax viz Ada's is that you have to explicitly insert dummy fields in the record if you want non-contiguous fields. Conversely, C lacks the strong type checking that can make it more difficult to work with bit fields in Ada. I write these lines based in personal experience: without careful type definition, unchecked conversions become rampant when Ada is used at the bit level. Mark Von Hendy vonhend@ibm.net