Re: [vhdl-200x] VHDL support for Unicode

On 10/08/2011 13:17, David G. Koontz wrote:

> I was thinking of doing strings with 32 bit chars where you zero pad smaller
> values from the LSB. Unicode should parse cleanly and uniquely allowing a
> traversal to map multibyte chars to 32 bit (unsigned) chars.

I did initially go for UTF-32, but it turned out to be just too much
work to change all the string stuff for wide char handling, and to find
all the dependencies. The killer was that MS and Unix have different
ideas on what a 'wide' char is (16- vs. 32-bit). UTF-8 turned out to be
much easier, and seems to be what most other people have gone for.

> Semantic
> error handling would need to be considered

I'd forgotten that. If you advertise a language as Unicode-compliant,
people expect it to be fully internationalised. There's not much point
typing Sanskrit identifiers and getting English error messages. I had to
strip out several hundred warning and error messages and make the whole
messaging system table-driven, so that messages could be replaced with
local versions. That was a *lot* of work, and difficult to test.

> If you look at the numbers of comments in Martin's three blog posts, there
> aren't enough to be statistically significant. I got two replies asking
> after users of an open source tool to which I have contributor access.

No, but you have to consider that the people who might be interested
probably aren't reading c.l.vhdl or English blog posts. Even so, I'd
still put this way down the list of requirements.

-Evan

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