Re: [PATCH 0/4] Fix caret errors

[Akim Demaille]

Hi Hans,

> Le 21 avr. 2019 à 23:14, Hans Åberg <address@hidden> a écrit :
> 
> 
>> On 21 Apr 2019, at 09:41, Akim Demaille <address@hidden> wrote:
>> 
>> So what shall we do?
>> 
>> 1.  Should we stick to treating tabs as magical characters wrt column
>>   numbers?  Doing so gives consistent locations for people who mix
>>   tabs and spaces.  But a. they need to also tabs of 8 spaces, and
>>   b. indenting the way we do is visually wrong.
>> 
>> 2.  How should we quote source?
>>   a. Do like Clang
>>   b. Do like GCC
>>   c. Do like Bison, i.e., consider this is an unimportant issue,
>>      people should not use tabs anyway :)
> 
> The only safe way is to replace the visible characters in the quoted string 
> with spaces, and then use an initial portion of that. Then you can count 
> characters as you like, probably tabs as 1.

What do you mean by "the only safe way"?  Paul's proposal a la diff -T,
or GCC9's approach both seem to work properly.

> Does not work with Unicode, though. In your example
>> input.y:15.4-17: warning: empty rule without %empty [-Wempty-rule]
>> e: {∇⃗×𝐸⃗ = -∂𝐵⃗/∂t}
>>    ^~~~~~~~~~~~~~
> here, the U+20D7 COMBINING RIGHT ARROW ABOVE for the nabla combines, but 
> others do not.

What do you mean?  I see it perfectly: arrows are combined to E and B.
It might be something on your mail reader side?  For some reason, in
Apple's terminal, both nabla and B are correctly "accented", but not
the E.  All are correct in the mailer though.

It looks correct in Safari, and in Firefox (but less readable with the
latter).

https://lists.gnu.org/archive/html/bison-patches/2019-04/msg00017.html