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Re: [Xen-devel] [PATCH 1 of 4] xl: idl: Abolish keyed union types

Gianni Tedesco writes ("[Xen-devel] [PATCH 1 of 4] xl: idl: Abolish keyed union 
> xl: idl: Abolish keyed union types
> Since the IDL file has become useful for generating language
> bindings it has become apparent that the KeyedUnion type has no
> straightforward translation to scripting languages which have no
> notion of unions.

Uhh?  Most scripting languages' aggregate types are practically
nothing _but_ unions!

The correct translation of a keyed union would probably be an
aggregate (eg, in Python, a dictionary) containing an entry for the
key and entries for whatever version of the union it involved.

> Turns out this is only used in domain_build_info which is hardly a memory
> criticial structure.

However I don't have a strong opinion about the desirability of using
a tagged union for this particular structure.


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