-* Fixes
+Always check out the latest perl5-porters discussions on these subjects
+before embarking on an implementation tour.
-CC backend: goto, sort with non-default comparison. last for non-loop blocks.
-Version checking
-improve XSUB handling (both static and dynamic)
-sv_magic can do SvREFCNT_inc(obj) which messes up precalculated refcounts
-allocation of XPV[INAHC]V structures needs fixing: Perl tries to free
-them whereas the compiler expects them to be linked to a xpv[inahc]v_root
-list the same as X[IPR]V structures.
-ref counts
-perl_parse replacement
-fix cstring for long strings
-compile-time initialisation of AvARRAYs
-signed/unsigned problems with NV (and IV?) initialisation and elsewhere?
-CvOUTSIDE for ordinary subs
-DATA filehandle for standalone Bytecode program (easy)
-DATA filehandle for multiple bytecode-compiled modules (harder)
-DATA filehandle for C-compiled program (yet harder)
+Bugs
+ remove recursion in regular expression engine
+ fix memory leaks during compile failures
+ make signal handling safe
-* Features
+Tie Modules
+ VecArray Implement array using vec()
+ SubstrArray Implement array using substr()
+ VirtualArray Implement array using a file
+ ShiftSplice Defines shift et al in terms of splice method
-type checking
-compile time v. runtime initialisation
-save PMOPs in compiled form
-selection of what to dump
-options for cutting out line info etc.
-comment output
-shared constants
-module dependencies
+Would be nice to have
+ pack "(stuff)*", "(stuff)?", "(stuff)+", "(stuff)4", ...
+ contiguous bitfields in pack/unpack
+ lexperl
+ 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
+ -i rename file only when successfully changed
+ all ARGV input should act like <>
+ report HANDLE [formats].
+ support in perlmain to rerun debugger
+ 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
+ memory profiler: turn malloc.c:Perl_get_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)
+ 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
-* Optimisations
-collapse LISTOPs to UNOPs or BASEOPs
-compile-time qw(), constant subs
-global analysis of variables, type hints etc.
-demand-loaded bytecode (leader of each basic block replaced by an op
-which loads in bytecode for its block)
-fast sub calls for CC backend
+Possible pragmas
+ debugger
+ optimize (use less qw[memory cpu])
+
+Optimizations
+ constant function cache
+ switch structures
+ foreach(reverse...)
+ 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
+ tail recursion removal
+ "one pass" global destruction
+ rewrite regexp parser for better integrated optimization
+ LRU cache of regexp: foreach $pat (@pats) { foo() if /$pat/ }
+
+Vague possibilities
+ ref function in list context?
+ make tr/// return histogram in list context?
+ loop control on do{} et al
+ explicit switch statements
+ built-in globbing
+ compile to real threaded code
+ structured types
+ autocroak?
+ modifiable $1 et al
projects / p5sagit/p5-mst-13.2.git / blobdiff