Re: indsize: New module

[Paul Eggert]

On 12/3/20 6:25 AM, Bruno Haible wrote:
> /* The user can define UNSIGNED_INDSIZE_T, to get a different set of compiler
>     warnings.  */

I'm leery of this complexity, as it would change the semantics of what the type 
means. The type is not just about compiler warnings; it's about preferring 
signed integer arithmetic whenever possible to avoid unexpected results during 
comparisons and to catch integer overflow.

> typedef ptrdiff_t indsize_t;

The type name "indsize_t" is a bit long and this would detract from readability 
in programs that use a lot of indexes. I suggest "idx_t" instead.  dfa.c is 
already using this type name and it works well there.

dfa.c also has IDX_MAX. I suppose IDX_WIDTH would also be useful. I'm not so 
sure about PRIdIDX etc. as those macros make programs hard to read and I don't 
see much point to hiding the fact that the type is equivalent to ptrdiff_t. 
(dfa.c just uses %td etc. for printf formats.)