Re: A new notion: stronglly-typed-by-user language

["J-P. Rosen" <rosen@adalog.fr>]

Dmitry A. Kazakov a �crit :
> On Sat, 17 Apr 2010 07:25:25 +0200, J-P. Rosen wrote:
> 
>> Note that T'Base is the same type as T, so there is no issue here.
> 
> But it is not all same. The behavior of T'Base may differ, so it might be
> unsafe to use one as an equivalent of another in certain contexts
> (substitutability violation).
> 
T is a subtype (the first named subtype) of T'Base. This is not
different from any issue of type vs. subtype.

My point is that two objects are of the same type if they represent the
same abstraction. This is true of T and T'Base. Almost any language
behaves as if there were only one integer type (represented on various
number of bits depending on the constraints). This is somehow the
mathematical view. But since we are modelling real world object, it is
better to adopt a physicist point of view: objects have dimensions, and
it makes no sense to add apples and oranges. That's what I would call
strong typing.

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           J-P. Rosen (rosen@adalog.fr)
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