As reported in bug #18057, the extension unaccent removes in its rule
file whitespace characters that are intentionally specified when
building unaccent.rules from UnicodeData.txt, causing an incorrect
translation for some characters like numeric symbols. This is caused by
the fact that all whitespaces before and after the origin and target
characters are all discarded (this limitation is documented).
This commit makes possible the use of quotes around target characters,
so as whitespaces can be considered part of target characters. Some
target characters use a double quote, these require an extra double
quote.
The documentation is updated to show how to use quoted areas,
generate_unaccent_rules.py is updated to generate unaccent.rules and a
couple of tests are added for numeric symbols. While working on this
patch, I have implemented a fake rule file to test the parsing logic
implemented, which is not included here as it would just consume extra
cycles in the tests, and it requires the manipulation of an installation
tree to be able to work correctly.
As this requires a change of format in unaccent.rules, this cannot be
backpatched, unfortunately. The idea to use double quotes as escaped
characters comes from Tom Lane.
Reported-by: Martin Schlossarek
Author: Michael Paquier
Discussion: https://postgr.es/m/18057-62712cad01bd202c@postgresql.org
Apparently, the previous update
(2e0e066679) must have used a stale
input file and missed a few additions that were added shortly before
the CLDR release. Update this now so that the next update really only
changes things new in that version.
This has required an update of the python script generating the rules,
as its format has changed in release 29. This release has also added
new punctuation and symbols, and a new set of rules has been generated
to include them. The way to find newest versions of Latin-ASCII gets
also more clearly documented.
Author: Hugh Ranalli, Michael Paquier
Discussion: https://postgr.es/m/15548-cef1b3f8de190d4f@postgresql.org
Improve generate_unaccent_rules.py to handle composed characters whose base
is another composed character rather than a plain letter. The net effect
of this is to add a bunch of multi-accented Vietnamese characters to
unaccent.rules.
Original complaint from Kha Nguyen, diagnosis of the script's shortcoming
by Thomas Munro.
Dang Minh Huong and Michael Paquier
Discussion: https://postgr.es/m/CALo3sF6EC8cy1F2JUz=GRf5h4LMUJTaG3qpdoiLrNbWEXL-tRg@mail.gmail.com
Add Python script for buiding unaccent.rules from Unicode data. Don't
backpatch because unaccent changes may require tsvector/index
rebuild.
Thomas Munro <thomas.munro@enterprisedb.com>