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Date: Wed, 19 Dec 2012 09:35:56 +0100
From: Georg Bauhaus <rm.dash-bauhaus@futureapps.de>
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Subject: Re: Press Release - Ada 2012 Language Standard Approved by ISO
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Date: 2012-12-19T09:35:55+01:00
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On 19.12.12 00:24, Randy Brukardt wrote:
> "Robert A Duff" <bobduff@shell01.TheWorld.com> wrote in message
> news:wcc8v8vti17.fsf@shell01.TheWorld.com...

>> Why does everybody neglect predicates, which are more important
>> than pre/post/invariant?
>
> No idea. Perhaps it is because only "old Ada hands" really grok the idea of
> a constrained subtype, and a predicate is just a constraint on steroids
> (well, a more general constraint).

Being a function, maybe the power of a predicate is at first easier
to see by a "functional" programmer, who is used to predicates?

There is a need for a killer example, then. Maybe an algorithm that
approximates some complex result with the help of failing predicates.

For example, finding two primes related in a certain way
with the help of tasks while predicates steer the computation.