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From: jans@mako.UUCP (Jan Steinman)
Newsgroups: net.micro,net.lang
Subject: Re: Who Wants Ada?
Message-ID: <833@mako.UUCP>
Date: Wed, 19-Jun-85 12:42:08 EDT
Article-I.D.: mako.833
Posted: Wed Jun 19 12:42:08 1985
Date-Received: Fri, 21-Jun-85 02:53:06 EDT
References: <1649@reed.UUCP> <186@harvard.ARPA> <453@calmasd.UUCP> <192@harvard.ARPA> <266@sdcc13.UUCP>
Reply-To: jans@mako.UUCP (Jan Steinman)
Organization: Tektronix, Wilsonville OR
Lines: 23
Xref: watmath net.micro:10830 net.lang:1623
Summary: 

In article <266@sdcc13.UUCP> ee163acp@sdcc13.UUCP (DARIN JOHNSON) writes:
>In article <192@harvard.ARPA>, macrakis@harvard.ARPA writes:
>>It is certainly true that many current Ada compilers do not implement useful
>>Chapter 13 features, but since the most basic one, unchecked_conversion, is
>>so simple to implement (you just turn off type checking!), I believe most
>>compilers have it.  This is the main thing you need to do C-like low-level
>>pointer manipulations.
>
>...Wouldn't it be silly if they all tended to but unchecked_conversion at the
>start of all their programs.  Then when they wanted to make distributions,
>they would remove it...

You really missed the point.  If they simply removed the pragma, the code
probably fail to compile if they were doing anything funny.  It is true that
allocation and type checking costs, so in time or space critical code, the way
to do it is to do all the debugging and testing with the checks on, and then
add the pragmas (for performance reasons) before shipping.  How many times
during debugging has your only indication of anything wrong was "memory fault,
core dumped"?  Wouldn't it be much nicer to see "range of variable i exceeded
in procedure Array_Access"?
-- 
:::::: Jan Steinman		Box 1000, MS 61-161	(w)503/685-2843 ::::::
:::::: tektronix!tekecs!jans	Wilsonville, OR 97070	(h)503/657-7703 ::::::