Backward compatibility

[Dirk Herrmann]

Hello together,

I would like to remove the SCM_IM_ definitions from the public 
interface. Also, the definition of ilocs should not be public. These 
definitions should only be used as an internal interface, for example 
between memoization and execution. To make this possible and to clean up 
certain issues, I have some ideas about changing the type codes of 
immediates.

This, however, would influence the backwards compatibility. Later code 
would remain source code compatible, but not binary compatible. That is, 
the code would need to be recompiled.

I realize that you, Marius, have put a lot of effort to make guile 
backwards compatible. Do you intend to make it binary backwards 
compatible, or is it sufficient for you if Guile was sourcecode 
backwards compatible?

Best regards
Dirk