[M3devel] Integers

[Tony Hosking]

I think your confusion relates to understanding how the language defines "base" types.

You should understand that INTEGER and LONGINT have *different* base types.  This indicates that they have inherently different representations, and indeed, operations on INTEGER and operations on LONGINT are inherently different.

Every enumeration type similarly has a base type.  If it's range is expressed over INTEGER values then its base type is INTEGER.  If expressed over LONGINT then its base type is LONGINT.

I don't think I understand the rest of your questions.

On 7 Jan 2010, at 11:46, hendrik at topoi.pooq.com wrote:

> I have some questions as to the constraints that need to be placed on 
> integral types.  These issues are fundamental to an understanding of the 
> role of LONGINT, INTEGER, and CARDINAL, and what we should be doing 
> about them.
> 
> Is there a need for an integer type that can contain all the sizes of 
> integers that can be handled by the language?  I'll call it TOP just so 
> I can talk about it easily.
> 
> If it is necessary, is TOP only needed to make the language definition 
> clean and concise?  Conversely, is it necessary for TOP to be available 
> to programmers?  Is it necessary for TOP to be efficiently implemented, 
> or implemented at all?
> 
> Even if it is not available directly to programmers, are there language 
> features that require it internally?
> 
> Is it necessary that, for every two integer subranges I and J, there 
> exist an integer range K such that both I and J are subranges of K?
> 
> The most commonly used integral type is INTEGER.  It seems to be the 
> type used by programmers by default when they don't want to think of 
> the specific range they will need.  But is it necessary for the type 
> called INTEGER to be TOP?  Or, is there is no maximum implemented 
> integral type, is it still necessary for INTEGER to be a maximal 
> integral type?
> 
> -- hendrik

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