Re: client side syntax error localisation for psql (v1)

Dear Tatsuo,

Thanks for your reply, as I noticed from the source code that your name
often appears when dealing with multi-byte issues;-)

On Fri, 12 Mar 2004, Tatsuo Ishii wrote:
> As far as I understand your code, it will be broken on many multi byte
> encodings.
>
> 1) a character is not always represented on a terminal propotional to
> the storage size. For example a kanji character in UTF-8 encoding
> has a storage size of 3 bytes while it occupies spaces only twice
> of ASCII characters on a terminal. Same thing can be said to LATIN
> 2,3 etc. in UTF-8 perhaps.

I thought I dealt with that in the code by calling PQmblen for every char.
Am I wrong ?

> 2) It assume all encodings are "ASCII compatible". Apparently some
> client-side-only encodings do not satisfy this request. Examples
> include SJIS, Big5.

What I mean by "ASCII compatible" is that spaces, new lines, carriage
returns, tabs and NULL (C string terminaison) are one byte characters.
This assumption seemed pretty safe to me.

If this is not the case, I cannot understand how any error message could
work in psql. If one printf(" "), that would not be a space character?
Or is the terminal doing some "on the fly" translation?? What if a
file is read with such encoding??? Or is there a special compilation
option to generate special strings, but in this case the executable
would not be compatible with any other terminal????

Well, I just underline my lack of knowledge here:-(

If not, how can I detect these special characters that I need to change ?
Maybe I could translate the string to a pg_wchar[] if the function is
available to psql?

Also as I quick and dirty temporary fix, I can skip statement extraction
for those encodings that do not meet my expectations. So I would need to
know what encodings are at risk with the current scheme?

--
Fabien Coelho - coelho(at)cri(dot)ensmp(dot)fr