Re: [Gnu-arch-users] [BUG] feature plan -- version variables

[Tom Lord]

    > From: Aaron Bentley <address@hidden>

    > > Suppose a variable is locally set to #f.

    > > Then there's no reason to record in the patch log at all when a commit
    > > happens.   By omitting the variable from the patch log, you
    > > effectively set its patch-log value to #f.

    > Actually, I think it's worthwhile to preserve the distinction between 
    > missing and false.  In my work, I frequently encounter variables that 
    > should be treated as true if missing, and I think the problem could only 
    > be worse with a metadata system.  It's a distinction embraced by 
    > hackerlab's hashtrees and the C++'s std::map too.

    > Because you have to be able to answer the question: did they 
    > deliberately disable that?  Or were they unaware of the possibility of 
    > enabling that?

Yup, that'd be the opposing opinion on this, afaict, subjective call.

My feeling is that "default to #f" is dirt simple, fully general, easy
to understand, mostly easy to use, and in exceptional cases awkward.

I don't know any solution that has better properties.  I know of many
that have "no worse" properties except for the one property "dirt
simple".

All else being equal, the simplest thing wins.

-t