[Python-Dev] PEP-393: request for keeping PyUnicode_EncodeDecimal()

["Martin v. Löwis"]

> longobject.c still used PyUnicode_EncodeDecimal() until 10 months
> ago (8304bd765bcf). I missed the PyUnicode_TransformDecimalToASCII()
> commit, probably because #10557 is still open.
> 
> That's why I wouldn't like to implement the function myself at least
> until the API is settled.

I don't understand. If you implement it yourself, you don't have to
worry at all what the API is. Py_UNICODE_TODECIMAL has been around
for a long time, and will stay, no matter how number parsing is
implemented. That's all you need.

   out = malloc(PyUnicode_GET_LENGTH(in)+1);
   for (i = 0; i < PyUnicode_GET_LENGTH(in); i++) {
       Py_UCS4 ch = PyUnicode_READ_CHAR(in, i);
       int d = Py_UNICODE_TODIGIT(ch);
       if (d != -1) {
          out[i] == '0'+d;
          continue;
       }
       if (ch < 128)
          out[i] = ch;
       else {
          error();
          return;
       }
   }
   out[i] = '\0';

OTOH, *if* number parsing is ever updated (e.g. to consider alternative
decimal points), PyUnicode_EncodeDecimal still won't be changed - it
will continue to do exactly what it does today.

> Will PyUnicode_TransformDecimalAndSpaceToASCII() be public?

It's already included in 3.2, so it can't be removed that easily.
I wish it had been private, though - we have way too many API functions
dealing with Unicode.

Regards,
Martin