X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=Todo;h=eb13f6588e5a5d3a2ef541b2dfac044de5c3b68a;hb=7d3fb23018f73b213481a8b6b108e1dc03cefcff;hp=495be2ef3d1cb15218ee7dc3f778f4333694f21b;hpb=79ee829736f0059fc3a1c40f89ec42de04dad28e;p=p5sagit%2Fp5-mst-13.2.git

diff --git a/Todo b/Todo
index 495be2e..eb13f65 100644
--- a/Todo
+++ b/Todo
@@ -1,37 +1,88 @@
-* 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
+	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