19e7c0d2b5
There are (at least) two implementations of the low-level case-folding algorithm, one of which (for QChar::toLower()) seems to be wrong (it doesn't deal with special cases which expand to more than one code point). The algoithm hidden in QString and entangled with the QString detaching code makes reusing the code much harder. At the same time, the dependency of the algorithm on the unicode tables makes exposing a non-allocating result type in the public API hard. std::u16string would be an alternative if we can assure that all implementations use SSO with at least four characters. So, for the time being, leave this as internal API for use in an upcoming QStringView::toLower() as well as case-insensitive hashing. Change-Id: Iabb2611846f6176776aa20e634f44d8464f3305c Reviewed-by: Thiago Macieira <thiago.macieira@intel.com> |
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codecs/big5 | ||
data | ||
x11 | ||
.gitattributes | ||
main.cpp | ||
README | ||
unicode.pro | ||
writingSystems.sh |
Unicode is used to generate the unicode data in src/corelib/text/. To update: * Find the data (UAX #44, UCD; not the XML version) at ftp://www.unicode.org/Public/zipped/$Version/ * Unpack the zip file; for each file in data/, replace with the new version; find the *BreakProperty.txt in auxiliary/. (These last are only in the zip, not in the web-space's unpacked versions.) * In tst_QTextBoundaryFinder's data/ sub-directory, update its files from the auxiliary/ sub-directory of the UCD data. * If needed, add an entry to enum QChar::UnicodeVersion for the new Unicode version * In that case, also update main.cpp's initAgeMap and DATA_VERSION_S* to match * Build this project. Its binary, unicode, ignores command-line options and assumes it is being run from this directory. When run, it produces lots of output. If it gets as far as updating qunicodetables.cpp the output hopefully doesn't matter. * It'll end prematurely with a qFatal() message if it needs updates, either in main.cpp or in QChar: * "unassigned or unhandled age value:" initAgeMap() and QChar::UnicodeVersion; * "Unhandled script property value:" initScriptMap(), QChar::Script, qharfbuzzng.cpp's _qtscript_to_hbscript[] array and qfontconfigdatabase.cpp's specialLanguages. * "unassigned word break class:" enum WordBreakClass, word_break_class_string and initWordBreak(); * Assertions or other qFatal()s may trigger: if so, study code and understand what's more complicated about this update; talk to folk named in the git logs, maybe push a WIP to gerrit to solicit advice. Some bit-field may need to be expanded, for example. In some cases QChar may need additions to some of its enums. * Build with the modified code, fix any compilation issues, make check in suitable directories, including tst_QTextBoundaryFinder. * That may have updated qtbase/src/corelib/text/qunicodetables.cpp; if so the update matters; be sure to commit the changes to data/ at the same time and update text/qt_attribution.json to match; use the UCD Revision number, rather than the Unicode standard number, as the Version, for all that qunicodetables.cpp uses the latter (see the 'UAX #44, UCD' page linked from https://www.unicode.org/ucd/ for the table with this). * If there are enum additions in qchar.h (public API), be sure to also update the documentation in qchar.cpp for each affected enum, respecting the existing ordering. * If you don't normally build in the source tree, remember to delete qtbase/.qmake.stash while you're cleaning up. The script writingSystems.sh generates a list of writing systems, ostensibly as a the basis for updating QFontDatabase::WritingSystem enum; however, the Release 20 output of it contains many more writing systems than are present in that enum, suggesting it has not been run in a very long time. Further research needed.