On 26.01.2018 16:16, Random832 wrote: > On Fri, Jan 26, 2018, at 09:18, M.-A. Lemburg wrote: >> Is there a way to call an API which fixes the setting >> (a public version of unicode_adjust_maxchar()) ? >> >> Without this, how would an extension be able to provide a >> correct value upfront without knowing the content ? > > It obviously has to know the content before it can finally return the string > (or pass it to any other function, etc), because strings are immutable. Why > not then do all the intermediate work in an array of int32's (or perhaps a > UCS-4 PyUnicode to be returned only if needed), then afterward scan and build > the string?
The create, write data, resize approach is a standard way to build (longer) Pythhon string objects in the Python C API, since it avoids temporary copies. E.g. you don't want to first build a buffer to hold 100MB XML, then scan it for the max code point being used, create a python string from it (which copies the data into a second 100MB buffer) and then deallocate the first buffer again. Instead you create an uninitialized Python Unicode object and use PyUnicde_WRITE() to write the data directly into the object, avoiding the 100MB temp buffer. PS: Strings are immutable in Python, but they are not in C. You can manipulate string objects provided you own the only reference. -- Marc-Andre Lemburg eGenix.com Professional Python Services directly from the Experts (#1, Jan 26 2018) >>> Python Projects, Coaching and Consulting ... http://www.egenix.com/ >>> Python Database Interfaces ... http://products.egenix.com/ >>> Plone/Zope Database Interfaces ... http://zope.egenix.com/ ________________________________________________________________________ ::: We implement business ideas - efficiently in both time and costs ::: eGenix.com Software, Skills and Services GmbH Pastor-Loeh-Str.48 D-40764 Langenfeld, Germany. CEO Dipl.-Math. Marc-Andre Lemburg Registered at Amtsgericht Duesseldorf: HRB 46611 http://www.egenix.com/company/contact/ http://www.malemburg.com/ _______________________________________________ Python-ideas mailing list Python-ideas@python.org https://mail.python.org/mailman/listinfo/python-ideas Code of Conduct: http://python.org/psf/codeofconduct/
