+Always check out the latest perl5-porters discussions on these subjects
+before embarking on an implementation tour.
+
+Bugs
+ remove recursion in regular expression engine
+ fix memory leaks during compile failures
+ make signal handling safe
+
Tie Modules
VecArray Implement array using vec()
SubstrArray Implement array using substr()
ShiftSplice Defines shift et al in terms of splice method
Would be nice to have
- Profiler
- pack "(stuff)*"
- Contiguous bitfields in pack/unpack
+ pack "(stuff)*", "(stuff)?", "(stuff)+", "(stuff)4", ...
+ contiguous bitfields in pack/unpack
lexperl
- Bundled perl preprocessor
- Use posix calls internally where possible
- const variables
- gettimeofday
- bytecompiler
+ bundled perl preprocessor/macro facility
+ this would solve many of the syntactic nice-to-haves
+ use posix calls internally where possible
+ gettimeofday (possibly best left for a module?)
format BOTTOM
- $obj->can("method") to probe method inheritance
- -iprefix.
-i rename file only when successfully changed
- All ARGV input should act like <>
- Multiple levels of warning
+ all ARGV input should act like <>
report HANDLE [formats].
- tie(FILEHANDLE, ...)
- __DATA__
support in perlmain to rerun debugger
- make 'r' print return value like gdb 'fini'
- regression tests using __WARN__ and __DIE__ hooks
+ regression tests using __DIE__ hook
+ lexically scoped functions: my sub foo { ... }
+ the basic concept is easy and sound,
+ the difficulties begin with self-referential
+ and mutually referential lexical subs: how to
+ declare the subs?
+ lexically scoped typeglobs? (lexical I/O handles work now)
+ wantlvalue? more generalized want()/caller()?
+ named prototypes: sub foo ($foo, @bar) { ... } ?
+ regression/sanity tests for suidperl
+ 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
+ generalise Errno way of extracting cpp symbols and use that in
+ Errno, Fcntl, POSIX (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
+ cross-compilation support
+ host vs target: compile in the host, get the executable to
+ the target, get the possible input files to the target,
+ execute in the target (and do not assume a UNIXish shell
+ in the target! e.g. no command redirection can be assumed),
+ get possible output files back to to host. this needs to work
+ both during Configure and during the build. You cannot assume
+ shared filesystems between the host and the target (you may need
+ e.g. ftp), executing the target executable may involve e.g. rsh
+ a way to make << and >> to shift bitvectors instead of numbers
Possible pragmas
debugger
- optimize (use less memory, CPU)
+ optimize (use less qw[memory cpu])
Optimizations
constant function cache
switch structures
- foreach(@array)
- foreach (1..1000000)
foreach(reverse...)
- Set KEEP on constant split
- Cache eval tree (unless lexical outer scope used (mark in &compiling?))
+ 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
- sfio?
+ shrink opcode tables via multiple implementations selected in peep
+ cache hash value? (Not a win, according to Guido)
+ optimize away @_ where possible
+ tail recursion removal
"one pass" global destruction
- Optimize sort by { $a <=> $b }
- 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
- Populate %SIG at startup if appropriate
- sub mysplice(@, $, $, ...)
- data prettyprint function? (or is it, as I suspect, a lib routine?)
+ ref function in list context?
make tr/// return histogram in list context?
- undef wantarray in void context
- Loop control on do{} et al
- Explicit switch statements
- perl to C translator
- multi-thread scheduling
+ loop control on do{} et al
+ explicit switch statements
built-in globbing
compile to real threaded code
structured types
- paren counting in tokener to queue remote expectations
autocroak?
- Modifiable $1 et al
- substr EXPR,OFFSET,LENGTH,STRING
-
+ modifiable $1 et al