[Python-Dev] Unicode and Windows (original) (raw)

M.-A. Lemburg mal@lemburg.com
Tue, 21 Mar 2000 18:44:11 +0100

"Fred L. Drake, Jr." wrote:

M.-A. Lemburg writes: > And/or perhaps sepcific APIs for each OS... e.g. > > PyOSMBCSFromObject() (only on WinXX) > PyOSAppleFromObject() (only on Mac ;) Another approach may be to add some format modifiers: te -- text in an encoding specified by a C string (somewhat similar to O&) tE -- text, encoding specified by a Python object (probably a string passed as a parameter or stored from some other call) (I'd prefer the [eE] before the t, but the O modifiers follow, so consistency requires this ugly construct.) This brings up the issue of using a hidden conversion function which may create a new object that needs the same lifetime guarantees as the real parameters; we discussed this issue a month or two ago. Somewhere, there's a call context that includes the actual parameter tuple. PyArgParseTuple() could have access to a "scratch" area where it could place objects constructed during parameter parsing. This area could just be a hidden tuple. When the C call returns, the scratch area can be discarded. The difficulty is in giving PyArgParseTuple() access to the scratch area, but I don't know how hard that would be off the top of my head.

Some time ago, I considered adding "U+" with builtin auto-conversion to the tuple parser... after some discussion about the error handling issues involved with this I quickly dropped that idea again and used the standard "O" approach plus a call to a helper function which then applied the conversion.

(Note the "+" behind "U": this was intended to indicate that the returned object has had the refcount incremented and that the caller must take care of decrementing it again.)

The "O" + helper approach is a little clumsy, but works just fine. Plus it doesn't add any more overhead to the already convoluted PyArg_ParseTuple().

BTW, what other external char formats are we talking about ? E.g. how do you handle MBCS or DBCS under WinXX ? Are there routines to have wchar_t buffers converted into the two ?

-- Marc-Andre Lemburg

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