[m-rev.] for post-commit review: improve diagnostics for bad number literals

[Julien Fischer]

On Sun, 2 Jul 2023, Zoltan Somogyi wrote:

>
> On 2023-06-19 03:21 +02:00 CEST, "Julien Fischer" <jfischer at opturion.com> wrote:
>> I see no issue with
>> allowing underscores before exponents.
>
> The attached diff implements this change. For your post-commit
> review of the changes to the manual and to NEWS.md (the rest
> is trivial).

...

> Allow underscores before exponents in floats.
> 
> library/mercury_term_lexer.m:
>     As above.
> 
> NEWS.md:
>     Announce the change.
> 
> doc/reference_manual.texi:
>     Document the change.

...

> diff --git a/doc/reference_manual.texi b/doc/reference_manual.texi
> index 3c2463c99..95cce5bc0 100644
> --- a/doc/reference_manual.texi
> +++ b/doc/reference_manual.texi
> @@ -347,7 +347,8 @@ is the beginning of an octal escape;
>  as with hexadecimal escapes,
>  the sequence of octal digits must be terminated with a closing backslash.
> 
> -The sequence @samp{\u} or @samp{\U} can be used to escape Unicode characters.
> +The sequences @samp{\u} and @samp{\U}
> +start a specification for Unicode characters.

I suggest:

     The sequences @samp{\u} and @samp{\U} begin a Unicode character escape.

That looks fine otherwise.

Julien.