On Tuesday 06 May 2003 17:48, Todd Miller wrote:

Peter Verveer wrote:

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Hi,

In the numarray source code Bool is defined as a typedef to char. Does the Bool array type correspond to the Int8, or the UInt8 type? If I recall correctly, the char type may be signed or unsigned. Can I make any assumptions about the C type used to implement Bool at all?

Yes! It's named Bool. :)

Obviously, but then I need to include the numarray include file to make sure I get the right definition, and I do not always want to do that. See below.

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I guess at the Python level it does not matter what actual C type is used to implement bool arrays as it only represents boolean values. However, at the level of C extensions I would like to deal with Bool arrays by calling existing functions written for the appropiate C type.

The easiest way now is to just declare your variables with type "Bool". The only thing I can think of which that doesn't cover is printf/scanf. Are there others?

This does not work if you want to call a routine that was not written using the numarray typedefs. For instance, I like to write my array processing routines such that I can use them in a standalone C program without linking to numarray. These routines know nothing about numarray, but as long as the layout and data types of the arrays are correct I can still use them in numarray C routines. Then you need to know of course exactly what the C data types of the numarray routines are. That is easy for most types since they are exactly defined by bit-size and sign. But this is currently not true for the Bool type.

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That would be somewhat simpler if Bool is always garantueed to be either a unsigned or a signed char type.

I think perhaps we should just re-define Bool as signed char. Any other opinions?

That would solve the problem. Peter

On Tue, 2003-05-06 at 12:16, Francesc Alted wrote:

Mensaje citado por: Peter Verveer :

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That would be somewhat simpler if Bool is always garantueed to be either a unsigned or a signed char type.

I think perhaps we should just re-define Bool as signed char. Any other opinions?

That would solve the problem.

I'm in the same position than Peter. I would definitively prefer a standard C type for booleans.

Francesc Alted

I re-defined Bool as signed char in CVS. Without any real expertise in Boolology <ahem>, I am unqualified to comment further. Let me know if you would like something different. Todd

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