Re: Ichbiah's Letter

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On 2014-10-26, Jacob Sparre Andersen <jacob@jacob-sparre.dk> wrote:
>> https://duckduckgo.com/l/?kh=-1&uddg=http%3A%2F%2Fweb.elastic.org%2F~fche%2Fmirrors%2Fold-usenet%2Fada-with-null
>
> Reading the letter, I must say that I disagree with Ichbiah on some of
> the Ada 9X features which he wanted dropped:

> - Decimal types:
>
>   Okay. - One place where I must admit that I only know of example
>   sources using this.

In the IBM environment this is essential for financial applications. To
replace existing PL/I or COBOL systems or to allow Ada to be used for new
development in a large percentage of applications, support for decimal types
would have been essential. This is based on IBM's hardware decimal support
which was present from the beginning of S/360 in 1964, which is mostly
absent in other platforms (and should not be confused with floating point
decimal in IEEE or other variations). 

> + Unsigned types:
>
>   Something I use quite a lot and find it hard to imagine managing
>   without.  Also, how would one interface with C et al. without unsigned
>   types?

On a system where C is irrelevant (IBM until very recently) this
(C-interface) ould not have been an issue. Certainly at the time of Ada 95
C was irrelevant in the IBM environment. In general though, the absence of
unsigned types would have been a black mark in contending against PL/I for
example and possibly even COBOL.

> + Barriers:
>
>   One of those features I can't see how one can manage without.

Some hardware and OS don't require barriers. IBM MVS is an example where
this problem is defined away (does not apply) because the hardware and OS
specification precludes the issue from arising.