source: trunk/third/perl/Todo-5.6 @ 17035

Unicode support
    finish byte <-> utf8 and localencoding <-> utf8 conversions
    add Unicode::Map equivivalent to core
    add support for I/O disciplines
        - a way to specify disciplines when opening things:
            open(F, "<:crlf :utf16", $file)
        - a way to specify disciplines for an already opened handle:
            binmode(STDIN, ":slurp :raw")
        - a way to set default disciplines for all handle constructors:
            use open IN => ":any", OUT => ":utf8", SYS => ":utf16"
    eliminate need for "use utf8;"
    autoload byte.pm when byte:: is seen by the parser
    check uv_to_utf8() calls for buffer overflow
    make \uXXXX (and \u{XXXX}?) where XXXX are hex digits
        to work similarly to Unicode tech reports and Java
        notation \uXXXX (and already existing \x{XXXX))?
        more than four hexdigits? make also \U+XXXX work?
    overloadable regex assertions? e.g. in Thai \b cannot
        be deduced by any simple character class boundary rules,
        word boundaries must algorithmically computed

    see ext/Encode/Todo for notes and references about proper detection
    of malformed UTF-8

    SCSU?          http://www.unicode.org/unicode/reports/tr6/
    Collation?     http://www.unicode.org/unicode/reports/tr10/
    Normalization? http://www.unicode.org/unicode/reports/tr15/
    EBCDIC?        http://www.unicode.org/unicode/reports/tr16/
    Regexes?       http://www.unicode.org/unicode/reports/tr18/
    Case Mappings? http://www.unicode.org/unicode/reports/tr21/

    See also "Locales", "Regexen", and "Miscellaneous".

Multi-threading
    support "use Thread;" under useithreads
    add mechanism to:
      - create new interpreter in a different thread
      - exchange data between interpreters/threads
      - share namespaces between interpreters/threads
    work out consistent semantics for exit/die in threads
    support for externally created threads?
    Thread::Pool?

Compiler
    auto-produce executable
    typed lexicals should affect B::CC::load_pad
    workarounds to help Win32
    END blocks need saving in compiled output
    _AUTOLOAD prodding
    fix comppadlist (names in comppad_name can have fake SvCUR
        from where newASSIGNOP steals the field)

Namespace cleanup
    CPP-space:    restrict what we export from headers when !PERL_CORE
    header-space: move into CORE/perl/?
    API-space:    complete the list of things that constitute public api

Configure
    make configuring+building away from source directory work (VPATH et al)
        this is related to: cross-compilation configuring (see Todo)
    _r support (see Todo for mode detailed description)
    POSIX 1003.1 1996 Edition support--realtime stuff:
        POSIX semaphores, message queues, shared memory, realtime clocks,
        timers, signals (the metaconfig units mostly already exist for these)
        PREFERABLY AS AN EXTENSION
    UNIX98 support: reader-writer locks, realtime/asynchronous IO
        PREFERABLY AS AN EXTENSION
    IPv6 support: see RFC2292, RFC2553
        PREFERABLY AS AN EXTENSION
        there already is Socket6 in CPAN

Long doubles
    figure out where the PV->NV->PV conversion gets it wrong at least
    in AIX and Tru64 (V5.0 and onwards) when using long doubles: see the
    regexp tricks we had to insert to t/comp/use.t and t/lib/bigfltpm.t,
     (?:9|8999\d+) and the like.

64-bit support
    Configure probe for quad_t, uquad_t, and (argh) u_quad_t, they might
    be in some systems the only thing working as quadtype and uquadtype.
    more pain: long_long, u_long_long. 

Locales
    deprecate traditional/legacy locales?
    How do locales work across packages?
    figure out how to support Unicode locales
        suggestion: integrate the IBM Classes for Unicode (ICU)
        http://oss.software.ibm.com/developerworks/opensource/icu/project/
                ICU is "portable, open-source Unicode library with:
                charset-independent locales (with multiple locales
                simultaneously supported in same thread; character
                conversions; formatting/parsing for numbers, currencies,
                date/time and messages; message catalogs (resources);
                transliteration, collation, normalization, and text
                boundaries (grapheme, word, line-break))".
        Check out also the Locale Converter:
        http://alphaworks.ibm.com/tech/localeconverter
    There is also the iconv interface, either from XPG4 or GNU (glibc).
    iconv is about character set conversions.
    Either ICU or iconv would be valuable to get integrated
    into Perl, Configure already probes for libiconv and <iconv.h>. 

Regexen
   make RE engine thread-safe
   a way to do full character set arithmetics: now one can do
        addition, negate a whole class, and negate certain subclasses
        (e.g. \D, [:^digit:]), but a more generic way to add/subtract/
        intersect characters/classes, like described in the Unicode technical
        report on Regular Expression Guidelines,
        http://www.unicode.org/unicode/reports/tr18/
        (amusingly, the TR notes that difference and intersection
         can be done using "Perl-style look-ahead")
        difference syntax?  maybe [[:alpha:][^abc]] meaning
        "all alphabetic expect a, b, and c"? or [[:alpha:]-[abc]]?
        (maybe bad, as we explicitly disallow such 'ranges')
        intersection syntax? maybe [[..]&[...]]?
   POSIX [=bar=] and [.zap.] would nice too but there's no API for them
        =bar= could be done with Unicode, though, see the Unicode TR #15 about
        normalization forms:
        http://www.unicode.org/unicode/reports/tr15/
        this is also a part of the Unicode 3.0:
        http://www.unicode.org/unicode/uni2book/u2.html
        executive summary: there are several different levels of 'equivalence'
   trie optimization: factor out common suffixes (and prefixes?)
        from |-alternating groups (both for exact strings and character
        classes, use lookaheads?)
   approximate matching

Security
    use fchown, fchmod (and futimes?) internally when possible
    use fchdir(how portable?)
    create secure reliable portable temporary file modules
    audit the standard utilities for security problems and fix them

Reliable Signals
    custom opcodes
    alternate runops() for signal despatch
    figure out how to die() in delayed sighandler
    make Thread::Signal work under useithreads

Win32 stuff
    sort out the spawnvp() mess for system('a','b','c') compatibility
    work out DLL versioning

Miscellaneous
    introduce @( and @) because group names can have spaces
    add new modules (Archive::Tar, Compress::Zlib, CPAN::FTP?)
    sub-second sleep()? alarm()? time()? (integrate Time::HiRes?
        Configure doesn't yet probe for usleep/nanosleep/ualarm but
        the units exist)
    floating point handling: nans, infinities, fp exception masks, etc.
        At least the following interfaces exist: fp_classify(), fp_class(),
        class(), isinf(), isfinite(), finite(), isnormal(), unordered(),
        <ieeefp.h>, <fp_class.h> (there are metaconfig units for all these),
        fp_setmask(), fp_getmask(), fp_setround(), fp_getround()
        (no metaconfig units yet for these).
        Don't forget finitel(), fp_classl(), fp_class_l(), (yes, both do,
        unfortunately, exist), and unorderedl().
        PREFERABLY AS AN EXTENSION.
        As of 5.6.1 there is cpp macro Perl_isnan().
    fix the basic arithmetics (+ - * / %) to preserve IVness/UVness if
        both arguments are IVs/UVs: it sucks that one cannot see
        the 'carry flag' (or equivalent) of the CPU from C,
        C is too high-level...
    replace pod2html with new PodtoHtml? (requires other modules from CPAN)
    automate testing with large parts of CPAN
    turn Cwd into an XS module?  (Configure already probes for getcwd())
    mmap for speeding up input? (Configure already probes for the mmap family)
    sendmsg, recvmsg? (Configure doesn't probe for these but the units exist)
    setitimer, getitimer? (the metaconfig units exist)

Ongoing
    keep filenames 8.3 friendly, where feasible
    upgrade to newer versions of all independently maintained modules
    comprehensive perldelta.pod

Documentation
    describe new age patterns
    update perl{guts,call,embed,xs} with additions, changes to API
    convert more examples to use autovivified filehandles
    document Win32 choices
    spot-check all new modules for completeness
    better docs for pack()/unpack()
    reorg tutorials vs. reference sections
    make roffitall to be dynamical about its pods and libs