=head1 Tasks that only need Perl knowledge
+=head2 Smartmatch design issues
+
+In 5.10.0 the smartmatch operator C<~~> isn't working quite "right". But
+before we can fix the implementation, we need to define what "right" is.
+The first problem is that Robin Houston implemented the Perl 6 smart match
+spec as of February 2006, when smart match was axiomatically symmetrical:
+L<http://groups.google.com/group/perl.perl6.language/msg/bf2b486f089ad021>
+
+Since then the Perl 6 target moved, but the Perl 5 implementation did not.
+
+So it would be useful for someone to compare the Perl 6 smartmatch table
+as of February 2006 L<http://svn.perl.org/viewvc/perl6/doc/trunk/design/syn/S03.pod?view=markup&pathrev=7615>
+and the current table L<http://svn.perl.org/viewvc/perl6/doc/trunk/design/syn/S03.pod?revision=14556&view=markup>
+and tabulate the differences in Perl 6. The annotated view of changes is
+L<http://svn.perl.org/viewvc/perl6/doc/trunk/design/syn/S03.pod?view=annotate> and the diff is
+C<svn diff -r7615:14556 http://svn.perl.org/perl6/doc/trunk/design/syn/S03.pod>
+-- search for C<=head1 Smart matching>. (In theory F<viewvc> can generate that,
+but in practice when I tried it hung forever, I assume "thinking")
+
+With that done and published, someone (else) can then map any changed Perl 6
+semantics back to Perl 5, based on how the existing semantics map to Perl 5:
+L<http://search.cpan.org/~rgarcia/perl-5.10.0/pod/perlsyn.pod#Smart_matching_in_detail>
+
+
+There are also some questions that need answering:
+
+=over 4
+
+=item *
+
+How do you negate one? (documentation issue)
+http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2008-01/msg00071.html
+
+=item *
+
+Array behaviors
+http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2007-12/msg00799.html
+
+* Should smart matches be symmetrical? (Perl 6 says no)
+
+* Other differences between Perl 5 and Perl 6 smart match?
+
+=item *
+
+Objects and smart match
+http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2007-12/msg00865.html
+
+=back
+
=head2 Remove duplication of test setup.
Schwern notes, that there's duplication of code - lots and lots of tests have
=over 4
-=item * C<cc (cc.U)>
+=item * C<cc> (in F<cc.U>)
This variable holds the name of a command to execute a C compiler which
can resolve multiple global references that happen to have the same
name. Usual values are F<cc> and F<gcc>.
Fervent ANSI compilers may be called F<c89>. AIX has F<xlc>.
-=item * ld (dlsrc.U)
+=item * C<ld> (in F<dlsrc.U>)
This variable indicates the program to be used to link
libraries for dynamic loading. On some systems, it is F<ld>.
=back
-There is an implicit historical assumption, probably from Perl 1, that C<$cc>
-is also the correct command for linking object files together to make an
-executable. This may be true on Unix, but it's not true on other platforms,
-and there are a maze of work arounds in other places (such as F<Makefile.SH>)
-to cope with this.
+There is an implicit historical assumption from around Perl5.000alpha
+something, that C<$cc> is also the correct command for linking object files
+together to make an executable. This may be true on Unix, but it's not true
+on other platforms, and there are a maze of work arounds in other places (such
+as F<Makefile.SH>) to cope with this.
Ideally, we should create a new variable to hold the name of the executable
linker program, probe for it in F<Configure>, and centralise all the special
case logic there or in hints files.
A small bikeshed issue remains - what to call it, given that C<$ld> is already
-taken (arguably for the wrong thing) and C<$link> could be confused with the
-Unix command line executable of the same name, which does something completely
-different. Andy Dougherty makes the counter argument "In parrot, I tried to
-call the command used to link object files and libraries into an executable
-F<link>, since that's what my vaguely-remembered DOS and VMS experience
-suggested. I don't think any real confusion has ensued, so it's probably a
-reasonable name for perl5 to use."
+taken (arguably for the wrong thing now, but on SunOS 4.1 it is the command
+for creating dynamically-loadable modules) and C<$link> could be confused with
+the Unix command line executable of the same name, which does something
+completely different. Andy Dougherty makes the counter argument "In parrot, I
+tried to call the command used to link object files and libraries into an
+executable F<link>, since that's what my vaguely-remembered DOS and VMS
+experience suggested. I don't think any real confusion has ensued, so it's
+probably a reasonable name for perl5 to use."
"Alas, I've always worried that introducing it would make things worse,
since now the module building utilities would have to look for
C<$Config{link}> and institute a fall-back plan if it weren't found."
-
+Although I can see that as confusing, given that C<$Config{d_link}> is true
+when (hard) links are available.
=head1 Tasks that need a little C knowledge
projects / p5sagit/p5-mst-13.2.git / blobdiff