Skip to content

Commit

Permalink
Refactor ROADMAP with recent accomplishments and task estimates.
Browse files Browse the repository at this point in the history
  • Loading branch information
@pmichaud
pmichaud committed Feb 25, 2010
1 parent e79112d commit 37e2865
Showing 1 changed file with 95 additions and 174 deletions.
269 changes: 95 additions & 174 deletions docs/ROADMAP
View file
@@ -1,105 +1,86 @@
Rakudo Roadmap
--------------

Last updated: 2009-10-20

This document identifies the current major milestones and tasks
planned for Rakudo development as of August 2009. The first
section identifies (in no particular order) large-scale and/or
significant development tasks that are currently being planned
or worked on by the development team. The second section
then identifies specific Perl 6 features and capabilities,
and maps each to the large-scale tasks on which the feature
currently depends. Overall we hope this gives a feel for
where current efforts are being placed and what we intend to
accomplish during the next 4-6 months.
Last updated: 2010-02-25

This document identifies the major tasks planned for Rakudo
development as of February 2010. Most of these tasks are
oriented around the Rakudo Star distribution, currently targeted
for late April, 2010 (shortly after the Rakudo #28 release).

The items below are given a 1-3 priority indicator for the
Rakudo Star release, where 1 is "really important", 2 is
"ought to have", and 3 is "nice to have". Each item also
has from one to five asterisks indicating the estimated
"degree of effort" required for the item. Some items also
have additional notes (A-Z) of larger-scale issues or
considerations for the item. Finally, we've also provided
an indication of the person(s) most likely to be working
on the item; this is not intended to preclude or discourage
others from doing so.

Patches to this document are welcome.


Large-scale tasks
-----------------

A. PGE refactors: The Parrot Grammar Engine (PGE) is currently
being replaced by a parser written in NQP; this rewrite includes
the ability to implement protoregexes and longest token matching.
The goal is to get something that is much closer to what is being
used to develop STD.pm.
The development is being conducted in a project called nqp-rx on
github: <http://github.com/perl6/nqp-rx>.
Patrick Michaud is leading this development.

B. Parrot calling conventions: As of May 2009, Parrot's
calling conventions do not facilitate all of the dispatch
mechanisms needed for Perl 6; in particular, Parrot does
not cleanly support "named-only" parameters, binding named
arguments to positional parameters, or collecting arguments
into "captures". These features are currently scheduled
to be implemented by the November 2009 Parrot release.

C. Rakudo method and sub dispatch: As the Parrot calling
conventions evolve, Rakudo's existing dispatch (largely
written in a mixture of PIR and C) can be replaced by
much more efficient dispatch algorithms. This may also
involve significant refactors of the base Object class
and Parrot's P6object implementation. Jonathan Worthington
is heading up this effort.

D. Parrot context and return continuation handling: Ideally
we'd like Parrot to directly support "leave" semantics -- i.e.,
forcing a sub (other than the current one) to return
and rolling up the dynamic stack as appropriate.
In addition, we'd like to be able to tag subs with
"exit handlers" -- code to be automatically invoked
on subroutine exit. Parrot has some (limited?) support
for these features; we need to investigate what exists
now and determine what needs to be added.

In particular, it's conjectured that "leave" and roll-up
capabilities should I<not> be implemented using exceptions
and exception handlers.

E. Lexical symbol management: Much of Rakudo and Parrot is
designed on a Perl 5 "package-based" model; by contrast,
most of Perl 6 is based purely on lexical scoping rules.
Rakudo will need some significant refactoring to change its
various package-based views of name lookups into equivalent
lexically-scoped ones. (Also partially blocking on A above.)

F. Laziness: Many operations in Rakudo are currently "eager";
these need to be into lazy equivalents. The first step of
this will be a substantial refactor of List, Array, and
Positional roles to avoid inheriting from Parrot's
ResizablePMCArray; afterwards we'll update these roles
to incorporate laziness. This task will also require
exploration of the Iterator role and specification.

G. Native types and compact structs: Currently we don't
have a detailed plan for handling "native types" (int, str,
num) or compact arrays and structs in Parrot, nor do we
have a definite timeline for creating a plan. Essentially
we're waiting for someone to step up to work on this task.
It will require some knowledge of PIR, C, and Parrot internals.

H. Perl 6 specification: Some items to be completed
really want/need spec clarification before a great detail
of progress can be made. Sometimes this is a catch-22,
in that the spec sometimes wants implementations to try
a variety of designs before settling on a specific design.
Either way, there's still a fair bit of spec work to be done,
especially for I/O, modules, language interoperability, and
STD.pm itself.

I. Parrot and other installation issues: As of this writing,
Rakudo still has minor issues working against an installed
Parrot; we also need to work out library storage and
resolution issues at each of the Parrot, Rakudo, and Perl 6
levels.

J. Other (non-spec) design issues. Some conventions about
modules and library management are not properly part of the
specification, but need to be designed in conjunction with
Parrot and other module expectations.
Really important items
1 * protoregexes in grammars (B, pmichaud)
1 ** complete lazy lists in Seq and Array (pmichaud, others)
1 * array/hash vivification (pmichaud)
1 *** REPL (D, pmichaud)
1 ** s/// (B)
1 ** regex modifiers (B, pmichaud)
1 ** item assignment (B, pmichaud)
1 * lexical variables in regexes (B, pmichaud)
1 ** operator overloading -- infix:, prefix:, postfix: (B, pmichaud)
1 ** speed issues and profiling (C, all)
1 ** operator adverbs (B, pmichaud)
1 ? lexical classes and roles (jnthn)
1 ** import module symbols into current lexical scope (D, pmichaud, jnthn)
1 ** improved error messages and failure modes (B, all)
1 ** basic Buf implementation (A)
1 * attention-grabbing examples (all)
1 ** release announcement draft (pmichaud, all)

Ought to have items
2 *** installation standards (A)
2 ** custom operators for circumfix:, postcircumfix: (B, pmichaud)
2 *** heredocs (B)
2 ** Rat, BigNum, numification improvements (C, colomon)
2 ** true hyper/cross/reverse/other metaoperators (B, pmichaud)
2 ** synopsis 19 handling (A, D, pmichaud, particle, others)
2 *** temp variables (C)
2 **** better longest token matching in regexes (A, D, pmichaud)
2 ? other S02 data types -- KeySet, KeyBag (A)
2 ? specialized Unicode bits -- .codes, .graphs, .bytes (A, C)

Nice to have items
3 *** array/hash element vivification via WHENCE (jnthn)
3 **** module versioning and download (A, jnthn, mberends, masak, others)
3 **** ENTER/LEAVE/LAST/NEXT/FIRST/REDO control blocks (C, Z4)
3 ? Perl 5 interop (Z5, jnthn)
3 ? Pseudo-packages MY, CONTEXT, OUTER, $?LINE, etc. (jnthn)
3 ? feed operators (jnthn)
3 **** macros (B, Z)
3 *** pod heredocs (B)
3 *** complete Buf implementation (C)
3 *** slice context (A, Z3)
3 ** native calling interface (A, C, Z4)
3 ** domain specific languages (A)
3 ? slice context (A, Z3)
3 ? sized types -- int32, int8 (C)
3 ? native typed scalars (C)
3 ? packed arrays (C)
3 ? compact structures (C)

Notes:
A. Involves Perl 6 spec updates/revisions: Some items
involve or require substantial updates or revisions to
the synopses in order to progress.

B. Requires some improvements to the grammar or grammar engine.

C. Some Parrot-level support and/or development needed.

D. Some NQP-level support and/or development needed.

Z. Explicitly postponed items: Some items we explicitly
postpone until later in Rakudo development. There are generally
Expand All @@ -112,82 +93,22 @@ a variety of reasons we might do this:
(Z5) the item appears to be Really Hard "right now"
(Z6) other blockers


Specific Perl 6 features and development tasks
----------------------------------------------

For each item below we've given a 1-3 priority for the April 2010
"Rakudo *" release, where 1 is "really important", 2 is "ought to have",
and 3 is "nice to have". Each item also lists any large-scale tasks
(from the section above) on which the item is currently blocking.
(If no large-scale tasks are given, it may simply be that we just
haven't got around to the problem yet.)

1 * protoregexes (A)
2 * longest token matching semantics in regexes (A)
1 * operator adverbs (A)
1 * quoting adverbs (A)
1 * regex modifiers (A)
3 * domain-specific languages (A)
1 * item assignment (A)
1 * lexical variable lookups in regexes (A)
2 * cleanly add circumfix:, postcircumfix:, other custom tokens (A)
3 * true hyper/cross/reverse/other metaoperators (A)

2 * better gather/take handling of arguments (H)

3 * ENTER/LEAVE/LAST/NEXT/FIRST/REDO control blocks (B,D)
2 * temp variables (D)

1 * lexical classes and roles (E)
1 * importing module symbols into the current lexical scope (E)
2 * develop installation standards (I, J)
3 * Pseudo-packages MY, CONTEXT, OUTER, $?LINE, etc. (D,E)

1 * lazy lists (F)
1 * array/hash element vivification (H, need Proxy class)
1 * array/hash vivification (need update undef/Failure role)
1 * lazy gather/take (F)
3 * feed operators (F)
3 * slice context (B,F,H,C?)

1 * Buf 1 - Rakudo * implementation (H)
3 * Buf 2 - complete implementation (G,H)
3 * Sized types -- int32, int8 (G)
3 * Native typed scalars (G)
3 * Packed arrays (G)
3 * Compact structures (G)
2 * Rat, BigNum, numification improvements (G,H)
2 * Other S02 data types -- KeySet, KeyBag (G,H)
2 * Specialized Unicode bits -- .codes, .graphs, .bytes (G,H)

2 * heredocs (A,H)
3 * pod heredocs (A,H)
3 * macros (A,H,Z)
3 * module versioning and download (I,J)

3 * native calling interface (B,H)
1 * speed issues (A,B,profiling tools)
1 * REPL
3 * Perl 5 interop (Z5)
1 * attention-grabbing examples
1 * improved error messages and failure modes (E)
1 * release announcement draft
2 * synopsis 19 handling
1 * correctly return failure instead of die

Completed ROADMAP items:
- * better return value checking (done)
- * clean up subtypes in multi-dispatch (done)
- * maintain candidate lists in lexicals (done)
- * overloadable postcircumfix:<[ ]> and postcircumfix:<{ }> (done)
- * proper trait definition and usage (need to fix edge cases)
- * binding named arguments to positional parameters (done)
- * using STD.pm (or close analog) for parsing (A)
- * lexicals refactor (A)
- * embedded closures in regexes (A)
- * declare contextual and lexical vars in regexes (A)
- * return multiple values from a sub (B,D)
- * unpacking arguments (B,C)
- * nested signatures (B)
- * captures in signatures and return values (B,H)
- better return value checking (done)
- clean up subtypes in multi-dispatch (done)
- maintain candidate lists in lexicals (done)
- overloadable postcircumfix:<[ ]> and postcircumfix:<{ }> (done)
- proper trait definition and usage (need to fix edge cases)
- binding named arguments to positional parameters (done)
- using STD.pm (or close analog) for parsing (done)
- lexicals refactor (done)
- embedded closures in regexes (done)
- declare contextual and lexical vars in regexes (done)
- return multiple values from a sub (done)
- unpacking arguments (done)
- nested signatures (done)
- captures in signatures and return values (done)
- array/hash element vivification via Proxy (done)
- better gather/take handling of arguments (done)
- lazy gather/take (done)

0 comments on commit 37e2865

Please sign in to comment.