Re: [PATCH 4/4] dfa: prefer signed integers for internals

[Paul Eggert]

On 12/11/19 5:21 PM, Bruno Haible wrote:
> Last time we were trying to find a good name for this typedef. How about
>
>    typedef ptrdiff_t uptrdiff_t;

"u" connotes "unsigned"; but "nonnegative but signed" is what is wanted 
here, and it is not the same thing.

Some of the ptrdiff_t values in dfa.c can be negative. Some can be -1 or 
nonnegative. Will we need more types for these other possibilities?

Also, where would we put these new typedefs? dfa.h doesn't seem like the 
right place.

>      It's quite possible that clang will have range types, 5 years from now.

I've been wanting, off and on, to get range types into the C world since 
the 1980s. It hasn't happened yet.