Re: is there a deep unyielding reason to limit U&'' literals to ASCII?

Robert Haas <robertmhaas@gmail.com> writes:
> On Sat, Jan 23, 2016 at 11:27 PM, Chapman Flack <chap@anastigmatix.net> wrote:
>> What I would have expected would be to allow <Unicode escape value>s
>> for any Unicode codepoint that's representable in the server encoding,
>> whatever encoding that is.

> I don't know anything for sure here, but I wonder if it would make
> validating string literals in non-UTF8 encodings significant more
> costly.

I think it would, and it would likely also require function calls to
loadable functions (at least given the current design whereby encoding
conversions are farmed out to loadable libraries).  I do not especially
want the lexer doing that; it will open all sorts of fun questions
involving what we can lex in an already-failed transaction.

It may well be that these issues are surmountable with some sweat,
but it doesn't sound like an easy patch to me.  And how big is the
use-case, really?
        regards, tom lane