パール2 で ポーション

p2 on potion

         .ooo
          'OOOo
      ~ p ooOOOo 2 ~
          .OOO
           oO      %% a fast perl5
             Oo
            'O
             `
            (o)
        ___/ /          
       /`    \ 
      /v^  `  ,
     (...v/v^/
      \../::/
       \/::/ 

parrot examples/benchmarks/fib.pir 28  1.746s
perl   examples/benchmarks/fib.pl  28  0.439s
potion examples/benchmarks/fib.pn  28  0.013s

parrot examples/benchmarks/fib.pir 40  3m36.447s
perl   examples/benchmarks/fib.pl  40  2m19.752s
potion examples/benchmarks/fib.pn  40  0m3.512s

• Using most of Damian Conway’s p5i recommendations:
  i.e. classes are immutable and final by default.
  See www.yetanother.org/damian/Perl5+i/

• Native and fast calling convention, no XS stack args on the heap.
  XS is replaced by dlcall (dynamic ffi), and/or shared libraries with
  normal function calls into the vm.

• int, str, num are objects, you can optionally type all args and lexical variables.
  In fact everything is an object as in parrot, even the compiler, the parser, the vm.

• Sized arrays are non-autovivifying and initialized with undef, resp. if typed 0, 0.0, "".
  

       my $a[3]; print $a[3];    => compile-time error: array out of bounds
       my int $i[3]; print $a[2] => 0
       my num $n[3]; print $n[2] => 0.0
       my str $s[3]; print $a[2] => ""
  

• A new pragma “no magic” applies to all visible objects in scope.

     {
       no magic;
       use Config;
       print $Config{’ccflags’};
     }
     => compile-time error: Invalid use of tie with no magic

use

     {
       no magic;
       use Config;
       print $Config::Config{’ccflags’};
     }

instead.

• p6-like dynamic, but fast meta object model: roles, :multi, type-optimizer.
  Like Moose, just better and much faster. (800x as first rough estimation)

• smartmatch works because all data are typed objects.

See p2-extensions for an overview on the planned perl5 language extensions, activated via the use p2; pragma.

See glossary for an overview on the potion/lua derived terminology.

See design-decisions why the code looks like asis, and what we want.

• Just-in-time compilation for x86, x86-64 and ppc done, missing is callcc for ppc and the arm jit.

• Intermediate bytecode format and VM. Load and dump code. Decent
  speed and cross-architecture. Heavily based on Lua’s VM.

• A multi-threaded concurrent generational GC, based on Stefan Seifert's
  work on hybrid parrot threads with proxies to safely update foreign
  variables via coroutines.
  The compiler will add hooks for objects leaving scope and add
  DESTROY method calls if they are visible at compile-time.
  Run-time created DESTROY methods will not be automatically called.
• The current potion generational GC is based on Basile Starynkevitch’s
  work on Qish.

• Bootstrapped “id” object model, based on Ian Piumarta’s soda
  languages. This means almost everything in the language, including
  object allocation and interpreter state are part of the object
  model. (See COPYING for citations.) The parser not yet, but this is planned.

• Interpreter is thread-safe and reentrant. This will
  facilitate coroutines, parallel interpreters and sandboxing.

• Lean, small, fast. Under 10kloc. Right now we’re like 6,000 or
  something. Install sloccount and run: make sloc.
  No configure, just make.

• Reified AST and bytecode structures. This is very important to
  me. By giving access to the parser and compiler, it allows people
  to target other platforms, write code analysis tools and even
  fully bootstrapped VMs. I’m not as concerned about the Potion VM
  being fully bootstrapped, especially as it is tied into the JIT
  so closely.

• Memory-efficient classes. Stored like C structs. Although the
  method lookup table can be used like a hash for storing arbitrary
  data.

• The JIT is also used to speed up some other bottlenecks. For
  example, instance variable and method lookup tables are compiled
  into machine code.

• Strings are immutable (like Lua and parrot) and byte arrays are used for I/O
  buffers. Strings are utf-8 only, de/encoding done in library functions.

• No arbitrary precision for numbers yet. Limited int range, no automatic int boxing nor promotion to bigint, bignum.

• Only preliminary error handling yet.

• No signal handling yet. (longjmp based)

development

• https://github.com/perl11/potion.git, branch p2
• no mailing list yet. fork, pull requests, comment, wiki, commit and create issues. irc://irc.perl.org/#perl11
• the plan is to have ~50% of perl5 parsed by summer 2013, add some basic libraries, and finish it by summer 2014.
• Travis

• p2 data structures (by doxygen)
• p2 reference (by global htags)
• glossary
• p2-extensions over perl5 (use p2;)
• design-decisions
• INTERNALS

thankyous

why the lucky stiff left the ruby community. potion was his last public project. It’s a work of art and mastership. I could not think of anything better. I think it is better than go, if potion would have had dlcall, autothreads and channels, arbitrary precision numbers and exception handling.

Rob Pike for go, and the parrot community for parrot.

cPanel for letting me do what I consider important. Not just 10% of my time as with Google.

Larry Wall for perl5. We miss his leadership and technical excellence. Without him nothing got done, and *if* something was done it was wrong. Besides defined-or, which left Tom Christiansen behind.

why the lucky stiff thanks:

I am gravely indebted to Basile Starynkevitch, who fielded my questions about his garbage collector. I favor French hackers to an extreme (Xavier Leroy, Nicolas Cannasse, Guy Decoux, Mathieu Bochard to name only a portion of those I admire) and am very glad to represent their influence in Potion’s garbage collector.

Matz, for answering my questions about conservative GC and for encouraging me so much. Potion’s stack scanning code and some of the object model come from Ruby.

Steve Dekorte for the Io language, libgarbagecollector and libcoroutine — I referred frequently to all of them in sorting out what I wanted.

Of course, Mauricio Fernandez for his inspiring programming journal housed at eigenclass.org/R2/ and for works derived throughout the course of it — extprot most of all. Many of my thoughts about language internals (object repr, GC, etc.) are informed by him.

Ian Piumarta for peg/leg and id-objmodel. I use a re-entrant custom version of peg, but the original library is sheer minimalist parsing amazement.

Final appreciations to Jonathan Wright and William Morgan who pitched in, back in the wee hours of Potion’s history. Thanks.

license