[m-rev.] for review/discussion: ill-formed sequences in Unicode strings

[Julien Fischer]

Hi Peter,

The diff is fine; it's certainly better that the current situation be
documented.  I'll comment on what we can do about it all separately.

On Thu, 5 Sep 2019, Peter Wang wrote:

>
> library/io.m:
> library/string.m:
>    Add warnings that Mercury strings are not limited to valid UTF-8 or
>    UTF-16.
>
> library/string.m
> library/string.format.m
> library/term_io.m
>    Note some current behaviours of predicates/functions when passed
>    strings containing invalid UTF-8 or UTF-16, and what to do about it.
>
> runtime/mercury_string.h:
>    Note behaviour of MR_utf8_encode.

Julien.