[m-rev.] for review: Reduce memory allocation in string.to_upper, string.to_lower.

[Zoltan Somogyi]

On Mon, 20 Jun 2016 14:13:13 +1000, Peter Wang <novalazy at gmail.com> wrote:
> +:- pragma foreign_proc("C",
> +    to_upper(StrIn::in, StrOut::uo),
> +    [will_not_call_mercury, promise_pure, thread_safe, will_not_modify_trail,
> +        does_not_affect_liveness, no_sharing],
> +"
> +    MR_Integer  i;
> +
> +    MR_make_aligned_string_copy_msg(StrOut, StrIn, MR_ALLOC_ID);
> +
> +    for (i = 0; StrOut[i] != '\\0'; i++) {
> +        if (StrOut[i] >= 'a' && StrOut[i] <= 'z') {
> +            StrOut[i] = StrOut[i] - 'a' + 'A';
> +        }
> +    }
> +").

The test here (and in to_lower) will do the wrong thing on machines that use EBCDIC.
While C# and Java won't use it, C might.

Zoltan.