Document tricks, work-arounds for user-defined casing

And add a .t file to verify that it works.

1 files changed, 100 insertions, 0 deletions

diff --git a/t/op/turkish.t b/t/op/turkish.t
new file mode 100644
index 0000000000..08e2baceb0
--- /dev/null
+++ b/t/op/turkish.t
@@ -0,0 +1,100 @@
+# Verifies that can implement Turkish casing as defined by Unicode 5.2.
+
+use Config;
+
+BEGIN {
+    chdir 't';
+    @INC = '../lib';
+    require './test.pl';
+}
+
+use subs qw(lc lcfirst uc ucfirst);
+
+sub uc($) {
+    my $string = shift;
+    utf8::upgrade($string);
+    return CORE::uc($string);
+}
+
+sub ucfirst($) {
+    my $string = shift;
+    utf8::upgrade($string);
+    return CORE::ucfirst($string);
+}
+
+sub lc($) {
+    my $string = shift;
+    utf8::upgrade($string);
+
+    # Unless an I is before a dot_above, it turns into a dotless i.
+    $string =~ s/I (?! [^\p{ccc=0}\p{ccc=Above}]* \x{0307} )/\x{131}/gx;
+
+    # But when the I is followed by a dot_above, remove the dot_above so
+    # the end result will be i.
+    $string =~ s/I ([^\p{ccc=0}\p{ccc=Above}]* ) \x{0307}/i$1/gx;
+    return CORE::lc($string);
+}
+
+sub lcfirst($) {
+    my $string = shift;
+    utf8::upgrade($string);
+
+    # Unless an I is before a dot_above, it turns into a dotless i.
+    $string =~ s/^I (?! [^\p{ccc=0}\p{ccc=Above}]* \x{0307} )/\x{131}/x;
+
+    # But when the I is followed by a dot_above, remove the dot_above so
+    # the end result will be i.
+    $string =~ s/^I ([^\p{ccc=0}\p{ccc=Above}]* ) \x{0307}/i$1/x;
+    return CORE::lcfirst($string);
+}
+
+plan tests => 22;
+
+my $map_directory = "../lib/unicore/To";
+my $upper = "$map_directory/Upper.pl";
+my $lower = "$map_directory/Lower.pl";
+my $title = "$map_directory/Title.pl";
+
+sub ToUpper {
+    my $official = do $upper;
+    $utf8::ToSpecUpper{'i'} = "\x{0130}";
+    return $official;
+}
+
+sub ToTitle {
+    my $official = do $title;
+    $utf8::ToSpecTitle{'i'} = "\x{0130}";
+    return $official;
+}
+
+sub ToLower {
+    my $official = do $lower;
+    $utf8::ToSpecLower{"\xc4\xb0"} = "i";
+    return $official;
+}
+
+is(uc("\x{DF}\x{DF}"), "SSSS", "Verify that uc of non-overridden multi-char works");
+is(uc("aa"), "AA", "Verify that uc of non-overridden ASCII works");
+is(uc("\x{101}\x{101}"), "\x{100}\x{100}", "Verify that uc of non-overridden utf8 works");
+is(uc("ii"), "\x{130}\x{130}", "Verify uc('i') eq \\x{130}");
+
+is(ucfirst("\x{DF}\x{DF}"), "Ss\x{DF}", "Verify that ucfirst of non-overridden multi-char works");
+is(ucfirst("\x{101}\x{101}"), "\x{100}\x{101}", "Verify that ucfirst of non-overridden utf8 works");
+is(ucfirst("aa"), "Aa", "Verify that ucfirst of non-overridden ASCII works");
+is(ucfirst("ii"), "\x{130}i", "Verify ucfirst('ii') eq \"\\x{130}i\"");
+
+is(lc("AA"), "aa", "Verify that lc of non-overridden ASCII works");
+is(lc("\x{C0}\x{C0}"), "\x{E0}\x{E0}", "Verify that lc of non-overridden latin1 works");
+is(lc("\x{0178}\x{0178}"), "\x{FF}\x{FF}", "Verify that lc of non-overridden utf8 works");
+is(lc("II"), "\x{131}\x{131}", "Verify that lc('I') eq \\x{131}");
+is(lc("IG\x{0307}IG\x{0307}"), "\x{131}g\x{0307}\x{131}g\x{0307}", "Verify that lc(\"I...\\x{0307}\") eq \"\\x{131}...\\x{0307}\"");
+is(lc("I\x{0307}I\x{0307}"), "ii", "Verify that lc(\"I\\x{0307}\") removes the \\x{0307}, leaving 'i'");
+is(lc("\x{130}\x{130}"), "ii", "Verify that lc(\"\\x{130}\") eq 'i'");
+
+is(lcfirst("AA"), "aA", "Verify that lcfirst of non-overridden ASCII works");
+is(lcfirst("\x{C0}\x{C0}"), "\x{E0}\x{C0}", "Verify that lcfirst of non-overridden latin1 works");
+is(lcfirst("\x{0178}\x{0178}"), "\x{FF}\x{0178}", "Verify that lcfirst of non-overridden utf8 works");
+is(lcfirst("I"), "\x{131}", "Verify that lcfirst('II') eq \"\\x{131}I\"");
+is(lcfirst("IG\x{0307}"), "\x{131}G\x{0307}", "Verify that lcfirst(\"I...\\x{0307}\") eq \"\\x{131}...\\x{0307}\"");
+is(lcfirst("I\x{0307}I\x{0307}"), "iI\x{0307}", "Verify that lcfirst(\"I\\x{0307}I\\x{0307}\") removes the first \\x{0307}, leaving 'iI\\x{0307}'");
+is(lcfirst("\x{130}\x{130}"), "i\x{130}", "Verify that lcfirst(\"\\x{130}\\x{130}\") eq \"i\\x{130}\"");