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=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID
	autolearn=no autolearn_force=no version=3.4.4
X-Google-Language: ENGLISH,ASCII-7-bit
X-Google-Thread: 103376,9c86eb13dd395066
X-Google-Attributes: gid103376,public
From: ohk@edeber.tfdt-o.nta.no (Ole-Hjalmar Kristensen FOU.TD/DELAB)
Subject: Re: CRC in Ada?
Date: 1997/03/07
Message-ID: <OHK.97Mar7080335@edeber.tfdt-o.nta.no>#1/1
X-Deja-AN: 223718634
References: <1997Mar2.220652@nova.wright.edu> <1997Mar5.083233.1@eisner>
Organization: Telenor Online Public Access
Newsgroups: comp.lang.ada
Date: 1997-03-07T00:00:00+00:00
List-Id: <comp.lang.ada>


In article <dewar.857652688@merv> dewar@merv.cs.nyu.edu (Robert Dewar) writes:

   Bob Duff said

   <<Agreed, but that's what inlining is for.  All I was saying is that there
   should be a standard package that does efficient I/O, with buffering,
   and of course you want to inline a call that just bumps a pointer and
   grabs a character out of a buffer (except in the rare case where the
   buffer is exhausted).  Unfortunately, Text_IO has an awful lot of
   nearly-useless cruft in it.  But why can't Stream_IO fit the bill here?>>

     It can, but be careful. If you write String'Input, then not only do you
     get the overhead of going character by character, unless a lot of
     special optimization is at work, but you also get the general inefficiency
     of dealing with unconstrained variable length objects, which usually
     involves at least one extra copy. The character by character reads come
     from the fact that this is the semantics of String'Input. yes, it could
     indeed be optimized (in the normal case, where a user level attribute is
     not supplied for type character), but you cannot count on that.

     More likely to be efficient is using Read and Write directly on
     buffers of stream elements.

     Indeed it is perfectly easy, and probably safest to do your own
     buffering in many cases (the same advice applies to C, it may be
     efficient to do indidvidual getchar's, but it may also be a disaster
     from an efficiency point of view.

It may certainly be less effective, but I cannot think of any
implementation where it would be a disaster. The C single char IO
operations are not complicated, and have very little overhead. What
makes you think otherwise?