Add in perldelta changes about unpack A and trailing whitespace, trie

[p5sagit/p5-mst-13.2.git] / pod / perltodo.pod

diff --git a/pod/perltodo.pod b/pod/perltodo.pod
index 1560956..ca6b345 100644 (file)
--- a/pod/perltodo.pod
+++ b/pod/perltodo.pod
@@ -27,6 +27,11 @@ it would be a good thing.
 
 Fix (or rewrite) the implementation of the C</(?{...})/> closures.
 
+=head1 A re-entrant regexp engine
+
+This will allow the use of a regex from inside (?{ }), (??{ }) and
+(?(?{ })|) constructs.
+
 =head1 pragmata
 
 =head2 lexical pragmas
@@ -112,11 +117,6 @@ Currently the %ENV entries are always byte strings.
 The regexp optimiser is not optional. It should configurable to be, to allow
 its performance to be measured, and its bugs to be easily demonstrated.
 
-=head2 common suffices/prefices in regexps (trie optimization)
-
-Currently, the user has to optimize C<foo|far> and C<foo|goo> into
-C<f(?:oo|ar)> and C<[fg]oo> by hand; this could be done automatically.
-
 =head1 POD
 
 =head2 POD -> HTML conversion still sucks
@@ -179,14 +179,12 @@ Clean these up. Move them to mathom.c, and don't compile for blead?
 The old perltodo notes "This has been done in places, but needs a thorough
 code review. Also fchdir is available in some platforms."
 
-=head2 foreach reverse
+=head2 Constant folding
 
-The old perltodo notes that we could optimise foreach to iterate in reverse.
-(instead of making a reversed copy on the stack)
-It seems that cx->blk_loop.itermax could be hijacked to act as a go up/go
-down flag, with cx->blk_loop.iterix primed in pp_enteriter for the go down
-case (ie reverse). However, it looks slightly tricky identifying the shape of
-foreach reverse in the optree in Perl_peep.
+The peephole optimiser should trap errors during constant folding, and give
+up on the folding, rather than bailing out at compile time.  It is quite
+possible that the unfoldable constant is in unreachable code, eg something
+akin to C<$a = 0/0 if 0;>
 
 =head1 Tests
 
@@ -198,10 +196,6 @@ Tests for everything, At which point Schwern coughs up $500 to TPF.
 
 A test suite for the B module would be nice.
 
-=head2 Improve tests for Config.pm
-
-Config.pm doesn't appear to be well tested.
-
 =head2 common test code for timed bailout
 
 Write portable self destruct code for tests to stop them burning CPU in
@@ -229,7 +223,7 @@ Currently perl from p4/rsync ships with a patchlevel.h file that usually
 defines one local patch, of the form "MAINT12345" or "RC1". The output of
 perl -v doesn't report that a perl isn't an official release, and this
 information can get lost in bugs reports. Because of this, the minor version
-isn't bumped up util RC time, to minimise the possibility of versions of perl
+isn't bumped up until RC time, to minimise the possibility of versions of perl
 escaping that believe themselves to be newer than they actually are.
 
 It would be useful to find an elegant way to have the "this is an interim
@@ -279,7 +273,7 @@ for example POSIX passes Exporter some very memory hungry data structures.
 
 =head2 Optimize away @_
 
-The old perltodo notes "Look at the "reification" code in C<av.c>"
+The old perltodo notes "Look at the "reification" code in C<av.c>".
 
 =head2 switch ops
 
@@ -301,3 +295,15 @@ be useful to have a reasonable general benchmarking suite that roughly
 represented what current perl programs do, and measurably reported whether
 tweaks to the core improve, degrade or don't really affect performance, to
 guide people attempting to optimise the guts of perl.
+
+=head2 readpipe(LIST)
+
+system() accepts a LIST syntax (and a PROGRAM LIST syntax) to avoid
+running a shell. readpipe() (the function behind qx//) could be similarly
+extended.
+
+=head2 Self ties
+
+self ties are currently illegal because they caused too many segfaults. Maybe
+the causes of these could be tracked down and self-ties on all types re-
+instated.