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: 103376,1fbce91fa69716f7 X-Google-Attributes: gid103376,public From: dennison@telepath.com Subject: Re: What good are File_Access's? Date: 1998/07/20 Message-ID: <6ovjqp$ki8$1@nnrp1.dejanews.com>#1/1 X-Deja-AN: 373157362 References: <6oo80p$m20$1@nnrp1.dejanews.com> Organization: Deja News - The Leader in Internet Discussion X-Article-Creation-Date: Mon Jul 20 14:22:17 1998 GMT Newsgroups: comp.lang.ada X-Http-User-Agent: Mozilla/4.0 (compatible; MSIE 4.0; Windows NT; Gateway2000) Date: 1998-07-20T00:00:00+00:00 List-Id: In article , dewar@merv.cs.nyu.edu (Robert Dewar) wrote: > T.E.D. said > > >It looks to me like the whole point of the File_Access type in Ada.Text_IO is > >to allow Standard_Output and Current_Output (and the same functions for Input > >and Error) to be compared in order to see if I/O has been redirected somehow. > No, the point of this feature is to allow you to save and restore the > value of Current_Output. Ted's theory is interesting, but there is nothing > in the RM to suggest that this equality test is expected to work, let alone > required to work! Ahhhh. That's the answer I was looking for. I didn't consider that as a possibility because that method of saving off the Current_Output won't work in a multi-tasking environment. You'd need some kind of "atomic" save-and-change operation. Since that is %90 of the Ada programs I have ever worked on, that doesn't make it too useful. It does look like it might have some application for streams too... > Indeed it is easy to imagine that two values designating the same file > would very likely not be equal. Apparently not. (sigh) Oh well. On to Plan B. T.E.D. -----== Posted via Deja News, The Leader in Internet Discussion ==----- http://www.dejanews.com/rg_mkgrp.xp Create Your Own Free Member Forum