[m-rev.] for review: Add conversion predicates between strings and UTF-8/UTF-16 code units.

[Julien Fischer]

Hi Peter,

On Wed, 25 Feb 2015, Peter Wang wrote:

> Add the predicates:

That won't look so good in the git logs, I suggest:

    Conversion of strings to lists of UTF-8/UTF-16 code units.

    Add the predicates:

> 	string.to_utf8_code_unit_list/2
> 	string.to_utf16_code_unit_list/2
> 	string.from_utf8_code_unit_list/2
> 	string.from_utf16_code_unit_list/2
>
> library/string.m:
> 	Implement the above predicates in Mercury code that works across
> 	backends.
>
> 	Add internal_encoding_is_utf8 helper predicate.
>
> 	Forward the new predicates, for which the named encoding matches
> 	that of the backend in use, to string.to_code_unit_list and
> 	string.from_code_unit_list.
>
> tests/hard_coded/Mmakefile
> tests/hard_coded/string_code_unit.exp
> tests/hard_coded/string_code_unit.m
> 	Add test case.
>
> NEWS:
> 	Announce the additions.

The diff looks fine, otherwise.

Cheers,
Julien.