support USE_THREADS+MULTIPLICITY; source compat tweaks for

[perl5.git] / Todo

diff --git a/Todo b/Todo
index 3fd0845..028a95e 100644 (file)
--- a/Todo
+++ b/Todo
@@ -1,3 +1,6 @@
+Always check out the latest perl5-porters discussions on these subjects
+before embarking on an implementation tour.
+
 Tie Modules
        VecArray                Implement array using vec()
        SubstrArray             Implement array using substr()
@@ -5,53 +8,70 @@ Tie Modules
        ShiftSplice             Defines shift et al in terms of splice method
 
 Would be nice to have
-       pack "(stuff)*"
-       Contiguous bitfields in pack/unpack
+       pack "(stuff)*", "(stuff)4", ...
+       contiguous bitfields in pack/unpack
        lexperl
-       Bundled perl preprocessor
-       Use posix calls internally where possible
+       bundled perl preprocessor
+       use posix calls internally where possible
        gettimeofday (possibly best left for a module?)
        format BOTTOM
        -i rename file only when successfully changed
-       All ARGV input should act like <>
+       all ARGV input should act like <>
        report HANDLE [formats].
        support in perlmain to rerun debugger
        regression tests using __DIE__ hook
-       reference to compiled regexp
        lexically scoped functions: my sub foo { ... }
        lvalue functions
+           wantlvalue?  more generalized want()/caller()?
+       named prototypes: sub foo ($foo, @bar) { ... } ?
        regression/sanity tests for suidperl
-       Full 64 bit support (i.e. "long long")
-       Generalise Errno way of extracting cpp symbols and use that in
+       iterators/lazy evaluation/continuations/first/
+           first_defined/short-circuiting grep/??
+           This is a very thorny and hotly debated subject,
+           tread carefully and do your homework first
+       full 64 bit support (i.e. "long long").  Things to consider:
+           how to store/retrieve 32+ integers into/from Perl scalars?
+           32+ constants in Perl code? (non-portable!)
+           32+ arguments/return values to/from system calls? (seek et al)
+           32+ bit ops (&|^~, currently explicitly disabled)
+       generalise Errno way of extracting cpp symbols and use that in
            Errno and Fcntl (ExtUtils::CppSymbol?)
+       the _r-problem: for all the {set,get,end}*() system database
+            calls (and a couple more: readdir, *rand*, crypt, *time,
+            tmpnam) there are in many systems the _r versions
+            to be used in re-entrant (=multithreaded) code
+            Icky things: the _r API is not standardized and
+            the _r-forms require per-thread data to store their state
+       memory profiler: turn malloc.c:Perl_dump_mstats() into
+           an extension (Devel::MProf?) that would return the malloc
+           stats in a nice Perl datastructure (also a simple interface
+           to return just the grand total would be good)
 
 Possible pragmas
        debugger
-       optimize (use less memory, CPU)
+       optimize (use less qw[memory cpu])
 
 Optimizations
        constant function cache
        switch structures
-       eval qw() at compile time
        foreach(reverse...)
-       Set KEEP on constant split
-       Cache eval tree (unless lexical outer scope used (mark in &compiling?))
+       optimize away constant split at compile time (a la qw[f o o])
+       cache eval tree (unless lexical outer scope used (mark in &compiling?))
        rcatmaybe
-       Shrink opcode tables via multiple implementations selected in peep
-       Cache hash value?  (Not a win, according to Guido)
-       Optimize away @_ where possible
+       shrink opcode tables via multiple implementations selected in peep
+       cache hash value?  (Not a win, according to Guido)
+       optimize away @_ where possible
        "one pass" global destruction
-       Rewrite regexp parser for better integrated optimization
+       rewrite regexp parser for better integrated optimization
        LRU cache of regexp: foreach $pat (@pats) { foo() if /$pat/ }
 
 Vague possibilities
-       ref function in list context
+       ref function in list context?
        make tr/// return histogram in list context?
-       Loop control on do{} et al
-       Explicit switch statements
+       loop control on do{} et al
+       explicit switch statements
        built-in globbing
        compile to real threaded code
        structured types
        autocroak?
-       Modifiable $1 et al
-
+       modifiable $1 et al