[m-rev.] for review: Document what whitespace means to library predicates.

[Julien Fischer]

Hi Peter,

On Mon, 2 Oct 2017, Peter Wang wrote:

> diff --git a/library/char.m b/library/char.m
> index b402784c5..9900ad5cc 100644
> --- a/library/char.m
> +++ b/library/char.m
> @@ -118,8 +118,14 @@
>     %
> :- pred is_ascii(char::in) is semidet.
> 
> -    % True iff the character is a whitespace character in the ASCII range,
> -    % i.e. a space, tab, newline, carriage return, form-feed, or vertical tab.
> +    % True iff the character is a whitespace character in the ASCII range:
> +    %
> +    %   U+0020  space
> +    %   U+0009  tab
> +    %   U+000A  line feed
> +    %   U+000B  vertical tab
> +    %   U+000C  form feed
> +    %   U+000D  carriage return
>     %
> :- pred is_whitespace(char::in) is semidet.

I would give both the Unicode name and the ASCII name where the two
differ, so:

   U+0020  space
   U+0009  character tabulation (horizontal tab)
   U+000A  line feed
   U+000B  line tabulation (vertical tab)
   U+000C  form feed
   U+000D  carriage return

Julien.