Subject Re: [firebird-support] Possible bug in
Author Helen Borrie
Hello Mark,

Tuesday, October 30, 2018, 8:20:51 AM, you wrote:

> On 29-10-2018 02:06, Helen Borrie helebor@...
> [firebird-support] wrote:
>> Character set NONE is a bare-bones ASCII set and does not provide
>> intrinsic support for any characters beyond the 128 characters that
>> provide the US-Ascii upper and lower case, numerals and the basic
>> diacritic symbols. You can store anything in charset NONE but nothing
>> in the least useful can be done with those incompatible characters.

> NONE only means store the bytes accepted and return them as is, and if a
> connection character set is specified, try to convert the stored bytes
> to that character set.

That much is true - but only if the first 128 characters of the
incoming set are compatible with those of US-Ascii.
> It does not mean or assume ASCII at all.

"At all" is too sweeping. The recognised alpha characters in NONE are
the unaccented a-z and A-Z of us-Ascii. Hence, if you are feeding in
strings that involve only those characters, you can UPPER and LOWER
them, and concatenate them.

> It just
> happens that most (all?) Firebird supported character sets (including
> UTF-8) use ASCII as the base for the first 128 characters.

Considering all supported character sets, not "most", not "all". It's
only true of character sets that can recognise those 7-bit characters
and can read the bytes in left-to-right order.
So -- most (if not all) Western character sets, few if any Eastern
ones that are stored in NONE.


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