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| author | Karl Williamson <khw@cpan.org> | 2016-04-12 11:21:40 -0600 |
|---|---|---|
| committer | Karl Williamson <khw@cpan.org> | 2016-05-24 10:26:29 -0600 |
| commit | 79f120c89a6e123770f65fd49893ef0b379cd922 (patch) | |
| tree | d2af18ebcc3405e8e660c3511ecdb39ca620f471 /pod/perllocale.pod | |
| parent | c664130fefeaef47ddc7dcbf7ec1830d04af8ea7 (diff) | |
| download | perl-79f120c89a6e123770f65fd49893ef0b379cd922.tar.gz | |
Change calculation of locale collation coefficients
Every time a new collation locale is set, two coefficients are calculated
that are used in predicting how much space is needed in the
transformation of a string by strxfrm(). The transformed string is
roughly linear with the the length of the input string, so we are
calcaulating 'm' and 'b' such that
transformed_length = m * input_length + b
Space is allocated based on this prediction. If it is too small, the
strxfrm() will fail, and we will have to increase the allotted amount
and try again. It's better to get the prediction right to avoid
multiple, expensive strxfrm() calls.
Prior to this commit, the calculation was not rigorous, and failed on
some platforms that don't have a fully conforming strxfrm().
This commit changes to not panic if a locale has an apparent defective
collation, but instead silently change to use C-locale collation. It
could be argued that a warning should additionally be raised.
This commit fixes [perl #121734].
Diffstat (limited to 'pod/perllocale.pod')
| -rw-r--r-- | pod/perllocale.pod | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/pod/perllocale.pod b/pod/perllocale.pod index d842a0781a..ddb60f2280 100644 --- a/pod/perllocale.pod +++ b/pod/perllocale.pod @@ -820,6 +820,9 @@ that a UTF-8 locale likely will just give you machine-native ordering. Use L<Unicode::Collate> for the full implementation of the Unicode Collation Algorithm. +If Perl detects that there are problems with the locale collation order, +it reverts to using non-locale collation rules for that locale. + If you have a single string that you want to check for "equality in locale" against several others, you might think you could gain a little efficiency by using C<POSIX::strxfrm()> in conjunction with C<eq>: |