I think for python at least if we were to treat ambiguous string values as text rather than data, we would be at odds with the python community's 2->3 migration plan. The following thread has a useful discussion of this that is worth a careful read:
http://stackoverflow.com/questions/1736228/python-data-vs-text/1736279#1736279 --Rafael On Wed, Aug 21, 2013 at 11:31 AM, Justin Ross <justin.r...@gmail.com> wrote: > Jimmy, thanks for getting this started. I'd love your feedback to > help sort this out. > > I think these are the cases: > > 1. If the language string is unambiguously textual, send it as amqp str16 > 2. If the language string is unambiguously arbitrary bytes, send it as > amqp vbin > > These are easy. We can tell the user's intention, and we can do the > right thing. > > 3. If the language string is an overloaded text/bytes type, as is > regrettably quite common, what do we do then? > > The current answer to this question is "send it as vbin". That's very > safe, insofar as it won't throw any sort of encoding exception. It > does not, however, always honor what I think is the user's more > typical intention: produce an ascii string at the other end. > > So for 3, I'd like to consider the possibility of, by default, sending > ambiguous language strings as ascii rendered to amqp str16. This > requires an encoding step that may produce errors. And maybe that's > just too obnoxious! That's what I'd like to know. > > In summary, if we have a way to determine what the user wanted (text > or bytes), we should try to carry that through on the wire. At the > following URL I've tried to map out what type information we can get > for each language. Please update it as you please. > > > https://cwiki.apache.org/confluence/display/qpid/Language+support+for+unambiguous+text+string+and+byte+array+types > > On Wed, Aug 21, 2013 at 8:44 AM, Jimmy Jones <jimmyjon...@gmx.co.uk> > wrote: > >> > AFAIK in perl, if you include unicode characters in a string it'll > >> > set the utf8 flag. If you don't include any unicode characters (eg. 7 > >> > bit ascii, or raw bytes) the flag won't be set. So given a perl > >> > scalar that doesn't contain any utf8 characters, you don't know if > >> > its a textual string (str16) or a binary string (vbin). There is a > >> > is_utf8_string function, but that'll only tell you if the string > >> > would be valid utf8, but it could be a binary string that happens to > >> > be valid utf8, so that's not really safe. > >> > >> You can explicitly mark it as utf8 using utf8::upgrade() though, right? > >> Certainly I tried that in a simple test and the property in question was > >> then sent as str16. > > > > Yes, if I as a user had a string that was textual, I could call > utf8::upgrade() to ensure it got sent as str16. I guess this is similar in > concept to calling setEncoding in C++, although maybe less natural in a > dynamically typed language. > > It would be more reasonable to treat perl scalars as textual for our > API if perl offered a good way to explicitly handle byte arrays. My > (certainly insufficient) web browsing suggested that wasn't really > available, or not in a form recommended for use. Any candidates for a > serviceable explicitly-arbitrary-bytes-and-not-text-at-all "type" in > perl? > > Thanks! > Justin > > --------------------------------------------------------------------- > To unsubscribe, e-mail: dev-unsubscr...@qpid.apache.org > For additional commands, e-mail: dev-h...@qpid.apache.org > >
