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From: "Jeffrey R. Carter" <spam.jrcarter.not@spam.not.acm.org>
Newsgroups: comp.lang.ada
Subject: Re: Mariner 1 / FORTRAN bug
Date: Fri, 9 Aug 2019 17:57:31 +0200
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Xref: reader01.eternal-september.org comp.lang.ada:57020
Date: 2019-08-09T17:57:31+02:00
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On 8/9/19 8:47 AM, Niklas Holsti wrote:
> On 19-08-09 09:28 , J-P. Rosen wrote:
>> Le 09/08/2019 à 03:57, robin.vowels@gmail.com a écrit :
>>>> While it probably didn't cause the failure of a space probe, people
>>>> did get bitten by this language design flaw, which is an example of a
>>>> single-character error (added, omitted, or changed) that results in valid
>>>> code.
>>> Single-character errors are still possible, whatever the language.
>>>
>> Of course, you can type "-" instead of "+" in any language.
>>
>> But outside of mathematical formulas, can you give an example of
>> single-character error in Ada?
> 
> I once declared a record type that contained a component, aptly (I thought) 
> called Address, of type System.Address.
> 
> Then, in a certain statement dealing with a record object R of that type, I 
> mistakenly wrote
> 
>     R'Address
> 
> when I meant
> 
>     R.Address

AIUI, a single-character error in a language design is one that is possible 
regardless of the developer's choice of identifiers. By that criterion, this is 
not a single-character error in the language design. Compare it to =/== in C and 
its descendants.

-- 
Jeff Carter
"[A] brilliant military career that after thirty
years catapulted him to the rank of corporal."
Take the Money and Run
138