Case Mappings? http://www.unicode.org/unicode/reports/tr21/
-lc(), uc(), lcfirst(), and ucfirst() work only for some of the
-simplest cases, where the mapping goes from a single Unicode character
-to another single Unicode character. See lib/unicore/SpecCase.txt
-(and CaseFold.txt).
+Mostly implemented (all of 1:1, 1:N, N:1), only the "final sigma"
+and locale-specific rules of SpecCase are not implemented.
=item *
http://archive.develooper.com/perl5-porters@perl.org/msg79618.html
-=head2 Better support for nonpreemptive threading systems like PTH
+=head2 Better support for nonpreemptive threading systems like GNU pth
-Perhaps do yield() before blocking calls, exchange calls to non blocking
-calls specific for those libraries (for example GNUpth has a pth_sleep
-which is a non pth aware version of sleep).
+To better support nonpreemptive threading systems, perhaps some of the
+blocking functions internally in Perl should do a yield() before a
+blocking call. (Now certain threads tests ({basic,list,thread.t})
+simply do a yield() before they sleep() to give nonpreemptive thread
+implementations a chance).
+
+In some cases, like the GNU pth, which has replacement functions that
+are nonblocking (pth_select instead of select), maybe Perl should be
+using them instead when built for threading.
=head2 Typed lexicals for compiler