Re: Referring to source code within Perldoc: the new A code
* Damian Conway ([EMAIL PROTECTED]) [070620 05:17]:
Feedback and suggestions are most welcome.
Clear and usable, in the boundaries you set to yourself.
Just my thoughts. A lot of questions and speculation, you do
not need to answer all. I'll try to only comment on this design,
and not restart our usual discussion.
role Transaction {
=alias class Arole
state Int $trans_counter;
=alias Vmy Int Astate Int
=DESCRIPTION
The Amy Int variable is used to track the total number of transactions
active at any one time. The value of Amy Int is incremented by the
Aclass CBUILD submethod and decremented by the Aclass destructor.
This is exactly the form of documentation you do *not* want the
user to write, for various reasons:
* it is stylish quite bad to repeat words like 'variable', 'class',
or 'method' in nearly every sentence. It makes manual-pages
painfully unpleasant.
* The explicit naming of the class name in method and attribute
descriptions is in general a bad idea: by inheritance, you get
sub-classes which also provide this method. In the people's
mind (I mean normal people, not our perl guru), this
requires continuous translations which distracts from the message.
h1class Transaction/h1
pThe transaction class defines the following methods and attributes./p
pThe $trans_counter variable is used to track the total number of
transactions active at any one time. The value of $trans_counter is
incremented by the Transaction BUILD submethod and decremented by
the Transaction destructor./p
pThe $max variable reports the number of Transaction objects which
are allowed to be processed in parallel. This is a constant value,
which defaults to 10./p
and so on. For many pages long. What, IMO, you want is a clean
and condensed way of expressing. At least I would prefer output
in this shape:
h1class Transaction/h1
pThe transaction class defines the following methods and attributes./p
ul
dtprivate attribute $trans_counter/dd
ddtracks the number of transactions actions active at any one time. The
value is incremented by BUILD() and decremented at Transaction
destruction./dd
dtpublic attribute $max (read-only, default 10)/dt
ddthe number of transactions are allowed to be processed in
parallel./dd
Concise, correct, and complete.
Of course, adapted to the features of the output channel, using
templates and style-sheets in the document generating tools.
* How do you see this syntactically work in combination with the
item list? At least the POD(5) needed that. I need a combined
example.
* Having aliases is pratical, for referencing. However, in this
latter example it is used to help the programmer to shoot himself
in the foot. If you allow people to say class each time they
mean role, or function where it is method, then on the long
run people will start making avoidable programming mistakes.
In the chosen approach, this abuse cannot be avoidable. But it
may be a wise not to promote it by using it as example.
* Using ambient back-references this way probably requires a
two-pass document generator. AFAIK this is not required for the
design of POD6 so far.
* the A(..) syntax is nice, but has a few dangers. Serious
problems. Your examples are a bit brief. A little larger:
method eat(Food $meal) {...}
=for DESCRIPTION
The Amethod() method has the following argument list: A(..)
Now the method gets implemented:
method eat(Food $meal) {
if($manger.isFull) { $manger.clean }
}
=for DESCRIPTION
The Amethod() method has the following argument list: A(..)
Oops... now the argument list became (without warning)
$manger.isFull So, either you impose a strict doc order, forcing
people into your style, or people have to use an alias everywhere,
bulking the file. More subtle examples of this problem can be
created, for instance when the method defines a return type
* In the manual-page of my sub-class, I want to refer to the
documentation of specific attributes and methods. How?
Can I also refer to elements in distributions which are not
mine, so where I cannot add X or such? For instance,
when I inherit from a core Perl class?
* In my sub-class, I want to enlist automatically the methods
and attributes which are inherited. Automatically of course,
because I want to avoid mistakes. In case of multi-level
inheritance, some way I need to know and show where each is
defined. How?
For instance, if your look at IO::File in Perl5, it defines
some own method, but then simply says: see also IO::Handle
and IO::Seekable. IO::Handle says: see also perlfunc and
perlvar. The more extended your OO model is, (Perl6's
structure is probably much more extended), the more levels
of hierarchy you get. Are users able to
Re: Query regarding Java/perl interface
On Wed, Jun 20, 2007 at 12:53:32PM +0800, Agent Zhang wrote: On 6/19/07, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: Hi I am sameer and am new to this group. It would realy help if any body can let me know is there a book or reference guiode where in i can get help regarding the perl/java interface and also about the tool named Java perl lingo. Java perl lingo, or JPL, was the name for some very early work done by Larry Wall to integrate Java and Perl5. As far as I know it was abandoned a few years ago. For the Java to Perl 5 interface, see Inline::Java on CPAN: http://search.cpan.org/dist/Inline-Java/ Inline::Java seems to be the main form of integration with perl5 these days. See http://search.cpan.org/~timb/JDBC/lib/JDBC.pm for an example. Tim. For a Java to Perl 6 API translator, see Java::Javap: http://search.cpan.org/perldoc?Java::Javap The author's journals may be helpful too: http://use.perl.org/~philcrow/journal Cheers, agentz
[perl #43261] [TODO] give STMVar some real documentation
# New Ticket Created by Allison Randal # Please include the string: [perl #43261] # in the subject line of all future correspondence about this issue. # URL: http://rt.perl.org/rt3/Ticket/Display.html?id=43261 The PMC src/pmc/stmvar.pmc currently shows up in the package information as XXX. http://search.cpan.org/~arandal/parrot-0.4.13/src/pmc/stmvar.pmc Allison
Re: Perl6 new features
cdumont wrote: I know that perl doesn't only focus on web apps and my question might seem irrelevant but I've been searching the web in order to find the new features of perl6 regarding new functions, core module lists (not perl grammar itself) but couldn't find any thing... Perl 6 is not yet finished, so the the list of core modules is not yet specified. I would like to develop web apps with perl too but having to download modules from CPAN every time makes me feel these apps will never be able to evoluate in different environments. (environments you don't have control of) That's a general problem with libraries, not only Perl ones. And you can't solve this by putting everything into core - it just blows up the distribution. I am a bit amazing to see that perl doesn't include a bunch a set theory functions too. Perl 6 does. See for example ext/Set/ in the pugs repository. And so does Perl 5: http://search.cpan.org/~samv/Set-Object-1.21/lib/Set/Object.pm I am not blaming perl but only hopes that perl6 will allow to make things easy for the programmer. That's one of the most important design goals ;-) as for the web, maintaining state thru server side cookies and DBI are the very minimum I would recommend. more hash and array functions a minimum too. if there are such things in perl6, I'll be very happy to work with this language ! You could help by contributing some suggestions to what the new Web module should be able to do, and how so. Web is hopefully CGI done right, and still in its early planning stage. Cheers, Moritz -- Moritz Lenz http://moritz.faui2k3.org/ | http://perl-6.de/ signature.asc Description: OpenPGP digital signature
Re: Parrot 0.4.13 Clifton Released
On Tue, Jun 19, 2007 at 10:53:07PM -0700, Allison Randal wrote:
Jonathan Scott Duff wrote:
- Misc:
+ Updated Parrot distribution to Artistic License 2.0, from dual
Artistic 1/GPL license.
Does this mean that Parrot is no longer dual licensed?
Yes. Under section 4(c)(ii) of Artistic 2.0 you can redistribute the
code under the GPL (any version), LGPL, or MPL, so there's no need
for dual licensing anymore.
Please find enclosed a modified .spec file for the new parrot's RPMs :)
Cheers,
D
--
David Fetter [EMAIL PROTECTED] http://fetter.org/
phone: +1 415 235 3778AIM: dfetter666
Skype: davidfetter
Remember to vote!
Consider donating to PostgreSQL: http://www.postgresql.org/about/donate
Name: parrot
Version:0.4.13
Release:1%{?dist}
Summary:Parrot Virtual Machine
License:Artistic 2.0
Group: Development/Libraries
URL:http://www.parrotcode.org/
Source0:
http://www.cpan.org/authors/id/A/AR/ARANDAL/parrot-%{version}.tar.gz
BuildRoot: %{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n)
BuildRequires: readline-devel
BuildRequires: ncurses-devel
BuildRequires: gmp-devel
BuildRequires: gdbm-devel
BuildRequires: /usr/bin/perldoc
BuildRequires: bc
BuildRequires: m4
BuildRequires: libicu-devel
BuildRequires: perl-SVK
%package devel
Summary:Parrot Virtual Machine development headers and libraries
License:Artistic 2.0
Group: Development/Libraries
Requires: %{name} = %{version}-%{release}
Requires: %{_libdir}/pkgconfig
%description
Parrot is a virtual machine designed to efficiently compile and
execute bytecode for interpreted languages. Parrot will be a target
for the Perl 6 compiler, and is already usable as a backend for
Pugs, as well as variety of other languages.
%description devel
Parrot Virtual Machine development headers and libraries.
%prep
%setup -q
%{__perl} -pi -e 's,lib/,%{_lib}/, if (/CONST_STRING\(interp,/)' \
src/library.c
%{__perl} -pi -e s,'/usr/lib','%{_libdir}',;s,runtime/lib/,runtime/%{_lib}/, \
tools/dev/install_files.pl \
tools/dev/mk_manifests.pl
%build
%{__perl} Configure.pl \
--prefix=%{_usr} \
--libdir=%{_libdir} \
--sysconfdir=%{_sysconfdir} \
--infodir=%{_datadir}/info \
--mandir=%{_mandir} \
--cc=%{__cc} \
--cxx=%{__cxx} \
--optimize=$RPM_OPT_FLAGS -maccumulate-outgoing-args \
--parrot_is_shared \
--lex=/usr/bin/flex \
--yacc=/usr/bin/yacc \
--libs='-lcurses -lm'
export LD_LIBRARY_PATH=$( pwd )/blib/lib
make
%install
rm -rf $RPM_BUILD_ROOT
export LD_LIBRARY_PATH=$( pwd )/blib/lib
make reallyinstall DESTDIR=$RPM_BUILD_ROOT
# Drop the docs so rpm can pick them up itself.
rm -rf $RPM_BUILD_ROOT/%{_docdir}/parrot
# Force permissions on doc directories.
find docs examples -type d -exec chmod 755 {} \;
find docs examples -type f -exec chmod 644 {} \;
# Force permissions on shared libs so they get stripped.
find $RPM_BUILD_ROOT%{_libdir} -type f \( -name '*.so' -o -name '*.so.*' \) \
-exec chmod 755 {} \;
# These files *probably* aren't needed.
rm -rf $RPM_BUILD_ROOT%{_usr}/compilers \
$RPM_BUILD_ROOT%{_usr}/config \
$RPM_BUILD_ROOT%{_includedir}/src \
$RPM_BUILD_ROOT%{_usr}/src
%check
export LD_LIBRARY_PATH=$( pwd )/blib/lib
# make test /dev/null
# %{?_with_fulltest:make fulltest /dev/null}
# make test || :
# %{?_with_fulltest:make fulltest || :}
%clean
rm -rf $RPM_BUILD_ROOT
%post -p /sbin/ldconfig
%postun -p /sbin/ldconfig
%files
%defattr(-,root,root,-)
%doc ABI_CHANGES ChangeLog CREDITS NEWS PBC_COMPAT PLATFORMS README
%doc RESPONSIBLE_PARTIES TODO
%doc docs examples
%exclude %{_bindir}/parrot-config
%{_bindir}/*
%{_libdir}/parrot
%{_libdir}/libparrot.so.*
%files devel
%defattr(-,root,root,-)
%{_bindir}/parrot-config
%{_includedir}/parrot
%{_libdir}/libparrot.so
%{_libdir}/libparrot.a
%{_libdir}/pkgconfig/*
%changelog
* Fri May 25 2007 David Fetter [EMAIL PROTECTED] 0.4.12-1
- Update to 0.4.12.
* Wed Apr 18 2007 Steven Pritchard [EMAIL PROTECTED] 0.4.11-1
- Update to 0.4.11.
* Wed Mar 21 2007 Steven Pritchard [EMAIL PROTECTED] 0.4.10-1
- Update to 0.4.10.
* Sat Mar 10 2007 Steven Pritchard [EMAIL PROTECTED] 0.4.9-1
- Update to 0.4.9.
- BR ncurses-devel.
- For some reason now I need to force -lm too.
- Remove some files/directories that shouldn't be included.
* Wed Jan 17 2007 Steven Pritchard [EMAIL PROTECTED] 0.4.8-1
- Attempt update to 0.4.8.
* Fri Jun 30 2006 Steven Pritchard [EMAIL PROTECTED] 0.4.5-5
- Override lib_dir and make various substitutions to try to fix multilib.
- Remove rpath use from Makefile.
- Fix a pod error in src/ops/experimental.ops.
- Enable make test since t/doc/pod.t won't fail now.
* Wed Jun 28 2006 Steven Pritchard [EMAIL PROTECTED] 0.4.5-4
- Force permissions on shared libraries so rpmbuild strips them.
* Wed Jun 28 2006 Steven Pritchard [EMAIL PROTECTED] 0.4.5-3
-
Re: Perl6 new features
Thank you for your kind reply ! Perl 6 is not yet finished, so the the list of core modules is not yet specified. I know that it is somehow not the subject, but I think the actual 5.8 doc should be changed to some extents. It could be nice if we could browse each core functions, having the function parameters, flags (not that much used right?), and the return value of the function, followed by exampleS AND so that it could be a lot richer, allow people to comment... I know this is not the point but it could be nice to do so for perl6 ! (I was thinking to create a kind of site like that for the actual perl, but my programming competences are,well... ) Perl 6 does. See for example ext/Set/ in the pugs repository. Glad to hear that ! You could help by contributing some suggestions to what the new Web module should be able to do, and how so. Web is hopefully CGI done right, and still in its early planning stage. Web module is a good name. Is there a place where we can add suggestions ? apart from the first one in... 2003 ? 4 years ago ? Moritz Lenz wrote: cdumont wrote: I know that perl doesn't only focus on web apps and my question might seem irrelevant but I've been searching the web in order to find the new features of perl6 regarding new functions, core module lists (not perl grammar itself) but couldn't find any thing... Perl 6 is not yet finished, so the the list of core modules is not yet specified. I would like to develop web apps with perl too but having to download modules from CPAN every time makes me feel these apps will never be able to evoluate in different environments. (environments you don't have control of) That's a general problem with libraries, not only Perl ones. And you can't solve this by putting everything into core - it just blows up the distribution. I am a bit amazing to see that perl doesn't include a bunch a set theory functions too. Perl 6 does. See for example ext/Set/ in the pugs repository. And so does Perl 5: http://search.cpan.org/~samv/Set-Object-1.21/lib/Set/Object.pm I am not blaming perl but only hopes that perl6 will allow to make things easy for the programmer. That's one of the most important design goals ;-) as for the web, maintaining state thru server side cookies and DBI are the very minimum I would recommend. more hash and array functions a minimum too. if there are such things in perl6, I'll be very happy to work with this language ! You could help by contributing some suggestions to what the new Web module should be able to do, and how so. Web is hopefully CGI done right, and still in its early planning stage. Cheers, Moritz -- シリル・デュモン（Cyrille Dumont） [EMAIL PROTECTED] our work is the portrait of ourselves tel: 03-5690-0230 fax: 03-5690-7366 http://www.comquest.co.j
Re: Perl6 new features
2007/6/20, cdumont [EMAIL PROTECTED]: I know that it is somehow not the subject, but I think the actual 5.8 doc should be changed to some extents. snip AND so that it could be a lot richer, allow people to comment... Well you can't comment it (CPAN Annotate allow you to comment the doc of any CPAN module though), but the perl documentation is quite extensive, and I for one don't understand what you mean by : It could be nice if we could browse each core functions, having the function parameters, flags (not that much used right?), and the return value of the function, followed by exampleS it seems to me that you already have this : in line of command you can use perldoc -f split to get the split() doc, where there are examples and return value and parameters are discussed at length, if you prefer a modern format, http://perldoc.perl.org/functions/split.html should content you, and you can use Pod::POM::Web to get a small HTTP server where all Perl doc (core and modules) can be browsed and searched, so what exactly are you speaking about ? -- Jedaï
Re: Perl6 new features
A: because it disrupts the natural way of thinking. Q: Why is top posting frowned upon? cdumont wrote: Perl 6 is not yet finished, so the the list of core modules is not yet specified. I know that it is somehow not the subject, but I think the actual 5.8 doc should be changed to some extents. You should discuss that on p5p, not here. Only Perl 6 is on topic here. Is there a place where we can add suggestions ? apart from the first one in... 2003 ? 4 years ago ? You can write them here on p6l. -- Moritz Lenz http://moritz.faui2k3.org/ | http://perl-6.de/ signature.asc Description: OpenPGP digital signature
Re: assign-if-uninitialized [Was: Generalizing ?? !!]
On 6/19/07, Larry Wall [EMAIL PROTECTED] wrote: On Tue, Jun 19, 2007 at 11:50:35AM -0400, Charles Bailey wrote: : Yep. For that matter, if I had to pick one change in this area that'd : have maximum impact, I'd say a good assign-if-uninitialized idiom : would be way ahead of an if-then-else idiom. Depending on how you mean uninitialized, that would be either: $x //= 42; # init if undefined or state $x = 42; # init first time through Both of which are getting borrowed back into Perl 5, as it happens. This is a Good Thing, on both counts. (I was thinking primarily of the former.) My intent was to say that I'm glad this was addressed in the design of P6, since it is, in my experience, a much more common version of the conditional assignment problem than the ternary operator. Yet another example of P6 doing things well. Rereading my original comment, I see this is less than clear. My apologies for the confusion. -- Regards, Charles Bailey Lists: bailey _dot_ charles _at_ gmail _dot_ com Other: bailey _at_ newman _dot_ upenn _dot_ edu
[perl #43246] [CAGE] Replace string_from_const_cstring() with string_from_cstring()
Greetings, On Mon Jun 18 16:57:45 2007, chromatic !-- x -- at wgz.org wrote: Per the note in src/string.c around line 509: /* XXX This is identical to string_from_cstring and should be removed */ PARROT_API STRING * string_from_const_cstring(Interp *interp, const char *buffer /*NULLOK*/, const UINTVAL len) ... replace all uses of string_from_const_cstring() with calls to string_from_cstring(), then remove this function. Replaced in r19164. Also replaced in languages/*, so, language maintainers, please verify that this change didn't brake anything. From my make tests everything looks ok. Probably needs a makeclean. Best regards, ./smash
bignum.c seems to be unused
bignum.c seems to be entirely unused. Everything builds just fine without it. There are many lint errors in it, such as int functions returning with return; and no value. Can we throw it away? Move it somewhere out of the way? -- Andy Lester = [EMAIL PROTECTED] = www.petdance.com = AIM:petdance
Re: [svn:perl6-synopsis] r14421 - doc/trunk/design/syn
In article [EMAIL PROTECTED], Chaddaï Fouché [EMAIL PROTECTED] wrote: The Learning Perl 6 argument seems equally contrived to me since anyway you don't need POD to understand programming in Perl and I never actually learned POD until I wanted to do a real module and document my little console utilities in Perl. That's exactly my argument. You didn't need to learn that because you weren't specifically doing anything with Pod. It doesn't even come up because it's something you have to affirmatively do, and it's not something that accidentally happens. And if some do it, hell, I seriously doubt that their program would be in the scope of the beginning of Learning Perl 6 !! You didn't put -+- there in previous versions, did you ? I'm not sure what you mean mean by - + -. Our current Learning Perl class starts off with a little Pod manipulation because we know that everyone (should!) has the perldoc along with their Perl. My actual experience trumps your serious doubt :) The other problem is that if somehow a braindead guy (where would he get the idea from, I never saw such a style) put his = in first column expecting a assignment he won't get it... Seriously ? Are you really allowing for such weirdness in introductory material to a Language course ? How is that braindead? It's perfectly fine, allowable, and intended that a Perl 5 programmer can break statements over more than one line. It's not weird at all. I've taught a lot of beginner Perl classes, and people do all sorts of things. So in my opinion, it would be fine to let slip that you can also create some kind of comment/doc by putting a = in the first column in the first chapter, and let the subject of POD for a later chapter. The problem is that once you bring something up, people want to know why you brought it up, and then they start playing with that point to see what you meant. All of a sudden, you're explaining a lot of stuff that doesn't get people any closer to completing a simple program. As I've said previously, the rule for Pod looks simple, but the rules for other things, such as strings, are now more complicated. However, Larry mentioned that the Pod extractor may do what it likes, but Perl shouldn't have to live with it's decisions about what is executable code and what isn't, so it may still work out.
Re: [svn:parrot] r19168 - trunk/src
On Wednesday 20 June 2007 07:57:15 [EMAIL PROTECTED] wrote: Modified: trunk/src/inter_call.c Log: Changed MAX to PARROT_MAX to avoid conflicts with any existing MAX Modified: trunk/src/inter_call.c === === --- trunk/src/inter_call.c (original) +++ trunk/src/inter_call.cWed Jun 20 07:57:14 2007 @@ -27,6 +27,8 @@ /* HEADER: include/parrot/inter_call.h */ +/* Make sure we don't conflict with any other MAX() macros defined elsewhere */ +#define PARROT_MAX(a,b) (((a)) (b) ? (a) : (b)) Alternately, we could hoist this macro into a header, rename it back to MAX, and define it only if no system header defines MAX. I think it's in math.h, but I'm not positive. -- c
Re: [svn:parrot] r19168 - trunk/src
On Jun 20, 2007, at 11:23 AM, chromatic wrote: Alternately, we could hoist this macro into a header, rename it back to MAX, and define it only if no system header defines MAX. I think it's in math.h, but I'm not positive. It's that I'm not positive that scares me, because on the BSD box I was using it was in something that wasn't math.h, which surprised me. So I did what I did. -- Andy Lester = [EMAIL PROTECTED] = www.petdance.com = AIM:petdance
Re: memcpy
I wasn't entirely happy with either option, so I asked around a bit for
other ideas. I like the macro approach below, it gives us both self
documentation and better checking for the size of the two structs.
Allison
Original Message
From: Nick Forrette [EMAIL PROTECTED]
To: Allison Randal [EMAIL PROTECTED]
This can be a bit brittle -- you have to be careful when changing the
type of dst else you could end up with over or underflow.
memcpy(dst, src, sizeof(FOO));
I do like memcpy because it serves as a red flag that a potentially
medium to large size hunk of memory will be copied here,
memcpy(dst, src, sizeof(*dst));
This gets you better type checking (if src and dst are different
struct types, the compiler will complain). Much harder to overflow dst
or only partially copy src.
*dst = *src;
Something like this can get you the best of the above, as long as
you're careful about size-effects (I'd have to double check to be
sure, but I believe there are differences with pre-increment/decrement
in a dereference/assignment v.s. two arguments to a function).
#define copy_struct(dst, src) \
(*(dst) = *(src))
copy_struct(dst, src);
You could use a more robust macro that does a run time check for size
effects:
// returns int so it can be used in a , expression
int myAssert(int thisIsABool)
{
assert(thisIsABool);
return 0;
}
#ifdef NDEBUG
#define macro_assert(thisIsABool) 0
#else
#define macro_assert(thisIsABool) myAssert(thisIsABool)
#endif
#define copy_struct(dst, src) \
(\
macro_assert((dst) == (dst)), \
macro_assert((src) == (src)), \
(*(dst) = *(src)) \
)
Gives you what I consider the best of all worlds. The compiler will
flag copying between different struct types, it is more robust in the
face of changed types for src or dst, in form that clearly spells out
what you're trying to do, that at least gives you run time checking
for abuse of side effects in debug builds.
Nick
Re: memcpy
On Jun 20, 2007, at 11:50 AM, Allison Randal wrote: I wasn't entirely happy with either option, so I asked around a bit for other ideas. I like the macro approach below, it gives us both self documentation and better checking for the size of the two structs. I guess I don't see the need to document a standard C behavior with a macro. We don't have #define inc(x) (x)++ do we? xoxo, Andy -- Andy Lester = [EMAIL PROTECTED] = www.petdance.com = AIM:petdance
Re: memcpy
On 6/20/07, Andy Lester [EMAIL PROTECTED] wrote: I guess I don't see the need to document a standard C behavior with a macro. We don't have #define inc(x) (x)++ do we? Incrementing a var is much less likely to have unpredictable effects due to modifying the wrong memory. Sure, x might be a pointer, and things might gang agley there, but pointers getting set to the wrong type of pointee is a pretty common problem, and one that I'm happy to have some runtime support in locating. -- Mark J. Reed [EMAIL PROTECTED]
Re: memcpy
On 6/20/07, Andy Lester [EMAIL PROTECTED] wrote: My point is that *d = *s; is no more a weird cryptic construct than n++; or while (*s) *d++ = *s++; for that matter. That's a very good point. As you said in the original message, all you need is *dest = *src; since the compiler will automatically complain if the two pointers don't point to the same type of object. AFAICT, the wrapping around the assignment in the macro just makes sure that there aren't any side effects - but the only reason side effects would be a problem is that it's a macro... -- Mark J. Reed [EMAIL PROTECTED]
Re: [svn:parrot] r19183 - in trunk: languages/m4/lib/Parrot/Test languages/plumhead/lib/Parrot/Test languages/plumhead/lib/Parrot/Test/Plumhead lib/Parrot
On Wednesday 20 June 2007 12:39:08 [EMAIL PROTECTED] wrote:
Modified: trunk/lib/Parrot/Test.pm
===
=== --- trunk/lib/Parrot/Test.pm(original)
+++ trunk/lib/Parrot/Test.pmWed Jun 20 12:39:06 2007
@@ -411,6 +412,76 @@
return $path;
}
+
+# These functions are only used by various
+# Parrot::Test::lang modules.
+# See RT#43266
+# This implementation is experimental and currently only works
+# for languages/plumhead
+sub generate_languages_functions {
+
+ my %test_map = (
+ output_is = 'is_eq',
+ output_like = 'like',
+ output_isnt = 'isnt_eq'
+ );
+
+ foreach my $func ( keys %test_map ) {
+
+ my $test_sub = sub {
+ my $self = shift;
+ my ( $code, $output, $desc, %options ) = @_;
+
+ my $count = $self-{builder}-current_test() + 1;
+
+ # These are the thing that depend on the actual language
implementation + my $out_fn = $self-get_out_fn( $count,
\%options ); + my $lang_fn = $self-get_lang_fn( $count,
\%options ); + my @test_prog = $self-get_test_prog( $count,
\%options ); +
+ Parrot::Test::write_code_to_file( $code, $lang_fn );
+
+ # set a TODO for Test::Builder to find
+ my $skip_why = $self-skip_why( \%options );
+ if ($skip_why) {
+ $self-{builder}-skip($skip_why);
+ }
+ else {
+
+ # STDERR is written into same output file
+ my $exit_code = Parrot::Test::run_command(
+ [EMAIL PROTECTED],
+ CD = $self-{relpath},
+ STDOUT = $out_fn,
+ STDERR = $out_fn
+ );
+
+ my $meth = $test_map{$func};
+
+ # That's the reason for: no strict 'refs';
+ my $pass = $self-{builder}-$meth(
Parrot::Test::slurp_file($out_fn), $output, $desc ); +
That line works under strict 'refs'; all method lookups are symbolic in Perl
5.
unless ($pass) {
+ my $diag = '';
+ my $test_prog = join ' ', @test_prog;
+ $diag .= '$test_prog' failed with exit code
$exit_code. if $exit_code; +
$self-{builder}-diag($diag) if $diag;
+ }
+ }
I think this code eats segfaults, as per RT #39197.
There's a lot of opportunity for refactoring and cleanup in the Parrot::Test
modules. There's too much duplication as it is.
-- c
[perl #43246] [CAGE] Replace string_from_const_cstring() with string_from_cstring()
Resolved in r19164, feel free to re-open if you find any problems. Best regards, ./smash
[perl #43269] [BUG] setline is tied to PIR source
# New Ticket Created by Patrick R. Michaud # Please include the string: [perl #43269] # in the subject line of all future correspondence about this issue. # URL: http://rt.perl.org/rt3/Ticket/Display.html?id=43269 The 'setline' opcode doesn't do what I expect it to do, which is to associate runtime errors with lines in HLL source. For example, suppose I have a program foo.p6 where lines 123 and 124 contain the statements $a = 9876; nsf($a + 1); A HLL compiler could then generate this as something like: .sub anon setfile foo.p6 setline 123 $P0 = new .Integer assign $P0, 9876 set_global '$a', $P0 setline 124 $P0 = get_global '$a' $P1 = clone $P0 add $P1, 1 'nsf'($P1) .end If the function 'nsf' doesn't exist, I expect get a runtime exception of some sort that says that the error occurred on line 124 of foo.p6. Currently parrot reports back that the error occurs in line 128, as in: Null PMC access in invoke() current instr.: 'anon' pc 27 (foo.p6:128) It appears to me that setfile and setline are currently being conflated with the PIR directive C #line file.ext nnn . I think we need both capabilities -- one to relate PIR compilation errors relative to a known location in PIR source (#line), and another to report runtime errors as a line number in HLL source (setfile+setline). RT #40806 has some related discussion for this. I'm also committing the above code as a test (currently failing). Another possibility may be to simply deprecate setfile/setline altogether, and require other tools (e.g., PAST-pm) generate code that sets global values somewhere for keeping track of the HLL source locations. Pm
question about t/operators/ternary.t
Looking at t/operators/ternary.t...
At the bottom of the file, there is a test that reads:
{
# This parses incorrectly because it's parsed as Bool::True(!! Bool::False).
my $foo = eval q[ 1 ?? Bool::True !! Bool::False ];
is($foo, Bool::True, a statement with both ??!! and :: in it did
compile), :todobug;
}
I'm not entirely certain what this test is intending to test.
Do we need it? Does it perhaps belong somewhere else?
Thanks,
Pm
small fixup and question for pdb
I'm starting to work on pdb for fixing bugs, segfaults and so, and maybe
implement new commands listed in TODO.
I noticed that command arguments does not support spacing between command
and argument. I have written a small patch that uses nextarg() for getting
command arguments. This means that now works things like:
(pdb) next 3
(pdb) next 4
but will not run the old-fashion commands:
(pdb) next3
imho the 'old' syntax is ugly, and we should relay on the new one checking for
spaces properly.
feel free to submit this patch if looks ok for you.
Thanks
--pancake
Index: src/debug.c
===
--- src/debug.c (revision 19192)
+++ src/debug.c (working copy)
@@ -460,6 +460,8 @@
if (!(pdb-state PDB_RUNNING))
PDB_init(interp, command);
+command = nextarg(command);
/* Get the number of operations to execute if any */
if (command isdigit((int) *command))
n = atol(command);
@@ -505,6 +507,7 @@
if (!(pdb-state PDB_RUNNING))
PDB_init(interp, command);
+command = nextarg(command);
/* if the number of ops to run is specified, convert to a long */
if (command isdigit((int) *command))
n = atol(command);
@@ -772,6 +775,7 @@
PDB_line_t *line;
long ln, i;
+command = nextarg(command);
/* If no line number was specified, set it at the current line */
if (command *command) {
ln = atol(command);
@@ -909,6 +913,7 @@
return;
}
+ command = nextarg(command);
ln = atol(command);
PDB_skip_breakpoint(interp, ln);
}
@@ -936,6 +941,7 @@
PDB_breakpoint_t *breakpoint;
long n;
+command = nextarg(command);
if (isdigit((int) *command)) {
n = atol(command);
breakpoint = interp-pdb-breakpoint;
@@ -1971,6 +1977,7 @@
return;
}
+command = nextarg(command);
/* set the list line if provided */
if (isdigit((int) *command)) {
line_number = atol(command) - 1;
@@ -2157,6 +2164,7 @@
long depth = 0;
Stack_Chunk_t *chunk = CONTEXT(interp-ctx)-user_stack;
+command = nextarg(command);
if (*command)
depth = atol(command);
Re: question about t/operators/ternary.t
On Wednesday 20 June 2007 15:53:59 Moritz Lenz wrote: Basically I think that - we need the test somewhere and - it is not a test that one would usually write unless he/she found a regression in one implementation. Therefore it would be good to have them somewhere separately, in an implementation-specific manner. That would reduce the wtf?-effect while reading the official tests. Of course all other implementations have to pass them as well... I'd suggest t/regression/$implementation/ in the pugs repository as the new location for such tests. That reminds me of a Jarkko quote from p5p: Crashes Perl (or Used To) is not a really useful classifying criterion, it's about as useful as the number of characters in the test is divisible by 73. If the test exercises something that's easy or possible to get wrong in any implementation, it belongs in the appropriate classification for that feature type for all implementations. -- c
Re: PMC Proxy high-level review
Hi, Allison Randal wrote: It looks like every low-level PMC is creating a proxy object for itself and these proxies are stored in the interpreter global parrot_interp_t. That's what's implemented, yes. I pondered hanging them off the v-table too. That's perhaps more desirable. I intended that proxies would only be created when they were needed by a subclassing Class PMC, and would only be stored in the Class PMC. I don't think this is the way to go. 1) It'd be good to be able to use the get_class opcode with PMCs as well as PDD15 classes. For that to Just Work, you need something hanging off the class slot of the appropriate namespace. That something is the PMCProxy. Thus it needs to be there from the start. 2) It's desirable that there is only ever one instance of PMCProxy per PMC. Then is this the same class is just a case of checking the pointers, as with PDD15 classes. Plus memory issues. 3) At the moment method lookup (for non-vtable methods, of course) is done through the namespace. We moved away from that in PDD15 classes, and with PMCProxy can do the same for methods of PMCs too. If you want to be able to have a list of methods inside PMCProxy, you need it stored somewhere runtime-accessible. If you're going to hang that data somewhere, why not just make the PMCProxy in the first place and store it in there. 4) PMCProxy also allows introspection of PMCs, not just placing them in an inheritance hierarchy. 5) It's just less code complexity to create them up-front. What was the motivation for having them instantiated lazily? Looking at the code from another perspective, though, maybe what we've got here is the beginning of an HLLSubclassable role that adds a handful of Class methods to low-level PMCs. I wander if we have different thoughts of what PMCProxy is supposed to achieve. Here's what I thought: when you have a PDD15 class, you have the instance of Class and you have the instance of Object. For PMCs, you have the second of these - an instance of the PMC. PMCProxy fills in the gap - it's like the Class PMC for PDD15, only for PMCs rather than PDD15 classes. Ultimately all PMCs need to be able to respond to inspect_str. Yeah, but there you're inspecting the object, not the class. Those are different, I think? And ultimately, all PMCs need to have an entry in their NameSpace so the type IDs can go away entirely. They already do, and by hanging PMCProxy off the class slot in the NameSpace PMC, we're a step closer to that, if it's the Right Thing to do. Thanks, Jonathan
Re: pdd15 - How do I add a class method?
Hi, Patrick R. Michaud wrote: My first question is How do I add a class method? -- i.e., a method that operates on a class instance as opposed to an object instance of that class. Ideally the answer would contain explanations/examples for defining such methods in PIR and also as PMC methods. I had to deal with this when working on the .Net translator, though I really fudged it. Basically, I just didn't have them as methods, but rather subs. That meant they didn't expect an invocant. And I translated the callmethod .Net op to do the Right Thing. Or something along those lines. The disadvantage is that they won't dispatch as methods on the instance of the object in Parrot-land (which is at least C# behavior...you can't call static methods using obj.meth, only class.meth, ignoring C# 3.0's extension methods). But that isn't Perl 6 behavior, as I understand it. How about writing the method without the :method modifier, but also addmethod'ing it to the class? Then it will be found by find_method, but won't think the first parameter is an invocant. Something here doesn't feel quite right to me, though I'm tired and can't put my finger on what. Jonathan
Re: [perl #43269] [BUG] setline is tied to PIR source
Patrick R.Michaud (via RT) wrote: The 'setline' opcode doesn't do what I expect it to do, which is to associate runtime errors with lines in HLL source. Currently HLL debug info stuff is spec'd, but not implemented. Well, OK, the storage of it in bytecode is spec'd, the exact PIR syntax for it isn't. So there are two tasks: implement the underlying storage model for this and sort out some PIR syntax for it. How important/blocking is this to you? I can direct some tuits this way in the near future if you're needing it. Jonathan
Re: [perl #43269] [BUG] setline is tied to PIR source
On Thu, Jun 21, 2007 at 12:08:33AM +0100, Jonathan Worthington wrote: Patrick R.Michaud (via RT) wrote: The 'setline' opcode doesn't do what I expect it to do, which is to associate runtime errors with lines in HLL source. Currently HLL debug info stuff is spec'd, but not implemented. Well, OK, the storage of it in bytecode is spec'd, the exact PIR syntax for it isn't. So there are two tasks: implement the underlying storage model for this and sort out some PIR syntax for it. How important/blocking is this to you? I can direct some tuits this way in the near future if you're needing it. Well, it's not too big a block for me personally. But for many other people who are now starting to work on testing the perl6 compiler or building the compiler itself, it's hugely frustrating (and I can understand that). For example, consider something like: $ cat foo.p6 use OtherModule; # imports some functions my $x = 1; bar($x); baz($x); Someone who runs this program gets the very cryptic: $ ../../parrot perl6.pbc foo.p6 Null PMC access in invoke() current instr.: 'parrot;Perl6::Compiler;main' pc 138 (perl6.pir:98) $ This doesn't give many clues about where the program is failing (perl6.pir:98 is the location of the rethrown exception). So, it's important (to others) but not currently a block (to me). I'll probably come up with a workaround in PAST.pm of some sort in the meantime. Personally, unless fixing this is very easy/straightforward I'd _much_ prefer to see some of the pdd15 items completed first. Thanks! Pm
Re: question about t/operators/ternary.t
chromatic wrote: On Wednesday 20 June 2007 15:53:59 Moritz Lenz wrote: Basically I think that - we need the test somewhere and - it is not a test that one would usually write unless he/she found a regression in one implementation. Therefore it would be good to have them somewhere separately, in an implementation-specific manner. That would reduce the wtf?-effect while reading the official tests. Of course all other implementations have to pass them as well... I'd suggest t/regression/$implementation/ in the pugs repository as the new location for such tests. That reminds me of a Jarkko quote from p5p: Crashes Perl (or Used To) is not a really useful classifying criterion, it's about as useful as the number of characters in the test is divisible by 73. There is a bit of a difference because there is just one Perl 5 implementation, but multiple Perl 6 implementations. If the test exercises something that's easy or possible to get wrong in any implementation, it belongs in the appropriate classification for that feature type for all implementations. I agree, but on the other hand it raised questions for somebody (Patrick) reading the test, although it was commented. How would you address the readability issue if you don't tests like these to separate files? Perhaps separate parse failure tests? -- Moritz Lenz http://moritz.faui2k3.org/ | http://perl-6.de/ signature.asc Description: OpenPGP digital signature
Re: Perl6 new features
You should discuss that on p5p, not here. Only Perl 6 is on topic here. Sure, but I've started from perl doc 5.8 in order to say that it could be nice to have the features I'm talking about in perl6 so it's not out of the scope I guess. it seems to me that you already have this : in line of command you can use perldoc -f split to get the split() doc, where there are examples and return value and parameters are discussed at length, if you prefer a modern format, http://perldoc.perl.org/functions/split.html should content you, and you can use Pod::POM::Web to get a small HTTP server where all Perl doc (core and modules) can be browsed and searched, so what exactly are you speaking about ? As for the documentation, I've already watched this link and depending on the functions, informations are more or left complete. In the case of split there are quite few examples but it's not the case for a lot of documentations. http://perldoc.perl.org/functions/chop.html http://perldoc.perl.org/functions/lc.html You might say that it doesn't need more but Adding user comments within the doc could allow to get much more usefull examples and 'tips' from other programmers. not a full blown oop cpan module but just a useful adding, transforming, real word use of the function. http://perldoc.perl.org/functions/pack.html This is an other function well documented. But if in split, the result of the example is included below the code with a sentence such as 'produces...' here, it is a comment below the line, or 'gives...' There's no real common pattern to get in a glimpse the function use. A kind of standardisation could help. (what are the arguments names, i've just found : EXPR, VALUE, Y,X,VARIABLE,NUMBER,PLAINTEXT...) there is a standard but it's not very as evident as it could be. function parameters,flags function return : .success:... .failure:... Example : ... Output : ... Well i'm talking about the 5.8 but remember it's in order to know if there can be ways of improvement for perl6 doc. Moritz Lenz wrote: A: because it disrupts the natural way of thinking. Q: Why is top posting frowned upon? cdumont wrote: Perl 6 is not yet finished, so the the list of core modules is not yet specified. I know that it is somehow not the subject, but I think the actual 5.8 doc should be changed to some extents. You should discuss that on p5p, not here. Only Perl 6 is on topic here. Is there a place where we can add suggestions ? apart from the first one in... 2003 ? 4 years ago ? You can write them here on p6l. -- シリル・デュモン（Cyrille Dumont） [EMAIL PROTECTED] our work is the portrait of ourselves tel: 03-5690-0230 fax: 03-5690-7366 http://www.comquest.co.j
Re: pdd15 - How do I add a class method?
From: Jonathan Worthington [EMAIL PROTECTED] Date: Thu, 21 Jun 2007 00:05:00 +0100 Hi, Patrick R. Michaud wrote: My first question is How do I add a class method? -- i.e., a method that operates on a class instance as opposed to an object instance of that class . . . A method that operates on a class instance would be an instance method of the class metaclass, wouldn't it? But I think you meant on a *particular* class [metaclass] instance, am I right? . . . How about writing the method without the :method modifier, but also addmethod'ing it to the class? Then it will be found by find_method, but won't think the first parameter is an invocant. Something here doesn't feel quite right to me, though I'm tired and can't put my finger on what. Jonathan But in order to be able to use class attributes, you would want the invocant to be the class metaclass instance, wouldn't you? If so, then I think this should be handled by a mechanism for defining a method on a particular object, which is useful for more than just metaclasses. I know of only two ways to define a method particular to an instance X (though this may say something about my lack of breadth in the language department): 1. In Ruby, the class of X is transparently subclassed into a virtual class that becomes the class of X only, and the method is defined (and dispatched) normally on the virtual class. 2. In Common Lisp, on can define a method for the object X, and this is handled by the dispatch machinery. Since the consequences of these strategies are visible to the programmer (foo.class in Ruby returns something different after def foo.meth . . ., but the class remains unchanged in Lisp), it seems like our hands are tied; both must be implemented in order to support both languages. But it's not clear to me that either needs to be in the core, nor which one would make the better default. Does anyone know of other strategies? For other languages with metaobjects (and, again, I confess I am not familiar with any), how do they do it? -- Bob Rogers http://rgrjr.dyndns.org/
Re: Referring to source code within Perldoc: the new A code
Mark Overmeer wrote:
This is exactly the form of documentation you do *not* want the
user to write, for various reasons:
Well, I agree it is the form that you (singular, specific) do not want; but
I'm not sure it's bad for you (plural, generic) to write in all cases. ;-)
* The explicit naming of the class name in method and attribute
descriptions is in general a bad idea: by inheritance, you get
sub-classes which also provide this method. In the people's
mind (I mean normal people, not our perl guru), this
requires continuous translations which distracts from the message.
A dedicated OO documentation tool could certainly do a better job in that
case, I heartily agree. I'm looking forward to using one.
* How do you see this syntactically work in combination with the
item list? At least the POD(5) needed that. I need a combined
example.
I'm not sure I understand what you're asking here. Can you describe the
example you'd like to see?
* Having aliases is pratical, for referencing. However, in this
latter example it is used to help the programmer to shoot himself
in the foot. If you allow people to say class each time they
mean role, or function where it is method, then on the long
run people will start making avoidable programming mistakes.
In the chosen approach, this abuse cannot be avoidable. But it
may be a wise not to promote it by using it as example.
A good point. I will remove the example.
* Using ambient back-references this way probably requires a
two-pass document generator. AFAIK this is not required for the
design of POD6 so far.
Actually a two-pass generator is already required for Pod. A second pass is
always necessary whenever there are any forward-targetted L#local link
formatting codes in a document.
* the A(..) syntax is nice, but has a few dangers. Serious
problems. Your examples are a bit brief. A little larger:
method eat(Food $meal) {...}
=for DESCRIPTION
The Amethod() method has the following argument list: A(..)
Now the method gets implemented:
method eat(Food $meal) {
if($manger.isFull) { $manger.clean }
}
=for DESCRIPTION
The Amethod() method has the following argument list: A(..)
Oops... now the argument list became (without warning)
$manger.isFull So, either you impose a strict doc order, forcing
people into your style, or people have to use an alias everywhere,
bulking the file. More subtle examples of this problem can be
created, for instance when the method defines a return type
Sure. But this is true of any scheme that doesn't do full parsing of the
ambient source code. Which Pod isn't going to do (but which, of course, you
may well choose to do in another documentation mark-up layer built on top of Pod).
* In the manual-page of my sub-class, I want to refer to the
documentation of specific attributes and methods. How?
Can I also refer to elements in distributions which are not
mine, so where I cannot add X or such? For instance,
when I inherit from a core Perl class?
This is not possible, using this mechanism, due to the lexical scoping of the
aliases. An automatic documentation-generator tool (that produces Pod) is more
appropriate for this task.
* In my sub-class, I want to enlist automatically the methods
and attributes which are inherited. Automatically of course,
because I want to avoid mistakes. In case of multi-level
inheritance, some way I need to know and show where each is
defined. How?
An automatic documentation-generator tool is more appropriate for this task too.
For instance, if your look at IO::File in Perl5, it defines
some own method, but then simply says: see also IO::Handle
and IO::Seekable. IO::Handle says: see also perlfunc and
perlvar. The more extended your OO model is, (Perl6's
structure is probably much more extended), the more levels
of hierarchy you get. Are users able to understand this?
Are developers able to maintain manual interface description
lists without mistakes?
Is the shown syntax sufficient for tools to create it
automatically? As decided, of course without looking at
the perl code itself.
Of course not. Pod is static explicit documentation mark-up. That mark-up may
be generated by humans or by clever documentation-from-code tools. Those
clever tools are what you're looking for, and what I'm sure you will easily be
able to create, using the Pod 6 and Perl 6 parsers as foundations, and perhaps
the Pod syntax as a output format (targetting the wealth of Pod-to-Whatever
translators we will provide).
Your design goal of A is to avoid replication of code information,
in which you succeeded. Now your write
method eat(Food $meal) {...}
=for DESCRIPTION
The Amethod() method has the following
[svn:parrot-pdd] r19204 - trunk/docs/pdds
Author: rgrjr Date: Wed Jun 20 19:02:42 2007 New Revision: 19204 Modified: trunk/docs/pdds/pdd15_objects.pod Log: * docs/pdds/pdd15_objects.pod: + Fix typo, canonicalize meta-classes. Modified: trunk/docs/pdds/pdd15_objects.pod == --- trunk/docs/pdds/pdd15_objects.pod (original) +++ trunk/docs/pdds/pdd15_objects.pod Wed Jun 20 19:02:42 2007 @@ -1195,7 +1195,8 @@ =head2 Meta-classes -Ruby: Ruby has meta classes. It would be nice if classes were objects in Parrots OO model. +Ruby: Ruby has meta-classes. It would be nice if classes were objects in +Parrot's OO model. =head2 Attributes
Re: pdd15 - How do I add a class method?
On Wed, Jun 20, 2007 at 09:41:00PM -0400, Bob Rogers wrote: From: Jonathan Worthington [EMAIL PROTECTED] Date: Thu, 21 Jun 2007 00:05:00 +0100 Hi, Patrick R. Michaud wrote: My first question is How do I add a class method? -- i.e., a method that operates on a class instance as opposed to an object instance of that class . . . A method that operates on a class instance would be an instance method of the class metaclass, wouldn't it? But I think you meant on a *particular* class [metaclass] instance, am I right? Yes, I believe this is a better phrasing. If I want to define a new method or or override an existing method on a metaclass instance [a class], then how do I do that? The particular instance I'm looking at is a CStr class for Perl 6, where I want the get_string vtable function for the CStr metaclass instance is different from get_string of a CStr class object. At the moment perl6 is handling this (in PMC classes) by checking the identify of the invocant when get_string is executed and then responding appropriately. But I'm thinking it's likely that CStr will be implemented using pdd15 objects, so I'm looking for the preferred approach for doing things like this. Thanks, Pm
Re: pdd15 - How do I add a class method?
From: Patrick R. Michaud [EMAIL PROTECTED] Date: Wed, 20 Jun 2007 21:02:54 -0500 On Wed, Jun 20, 2007 at 09:41:00PM -0400, Bob Rogers wrote: From: Jonathan Worthington [EMAIL PROTECTED] Date: Thu, 21 Jun 2007 00:05:00 +0100 Hi, Patrick R. Michaud wrote: My first question is How do I add a class method? -- i.e., a method that operates on a class instance as opposed to an object instance of that class . . . A method that operates on a class instance would be an instance method of the class metaclass, wouldn't it? But I think you meant on a *particular* class [metaclass] instance, am I right? Yes, I believe this is a better phrasing. If I want to define a new method or or override an existing method on a metaclass instance [a class], then how do I do that? AFAICS, there isn't currently a good way to do that. (Depending, of course, on whether you think Jonathan's suggestion qualifies. ;-) Nor does PDD15 seem to cover this; it actually says very little about metaclasses, beyond just the fact that they exist (and even then only mentions class metaclasses). The particular instance I'm looking at is a CStr class for Perl 6, where I want the get_string vtable function for the CStr metaclass instance is different from get_string of a CStr class object. To me, the phrases CStr metaclass instance and CStr class object sound like the same thing. Did you mean CStr object in the second case? If so, then get_string on the class metaclass would just affect the way the class stringifies, and not any of the instances, but I don't get the point of that. So I'm sure I must be misunderstanding you. Do you have an example? Maybe the perl6 code you mention? -- Bob
Re: [svn:parrot-pdd] r19204 - trunk/docs/pdds
On Wednesday 20 June 2007 19:02:43 [EMAIL PROTECTED] wrote: Modified: trunk/docs/pdds/pdd15_objects.pod -Ruby: Ruby has meta classes. It would be nice if classes were objects in Parrots OO model. +Ruby: Ruby has meta-classes. It would be nice if classes were objects in +Parrot's OO model. Classes are PMCs. Are there benefits to pushing them one step further and making them Objects as well? -- c
Re: pdd15 - How do I add a class method?
On Wed, Jun 20, 2007 at 10:38:08PM -0400, Bob Rogers wrote: From: Patrick R. Michaud [EMAIL PROTECTED] On Wed, Jun 20, 2007 at 09:41:00PM -0400, Bob Rogers wrote: Patrick R. Michaud wrote: My first question is How do I add a class method? -- i.e., a method that operates on a class instance as opposed to an object instance of that class . . . A method that operates on a class instance would be an instance method of the class metaclass, wouldn't it? But I think you meant on a *particular* class [metaclass] instance, am I right? Yes, I believe this is a better phrasing. If I want to define a new method or or override an existing method on a metaclass instance [a class], then how do I do that? AFAICS, there isn't currently a good way to do that. (Depending, of course, on whether you think Jonathan's suggestion qualifies. ;-) Nor does PDD15 seem to cover this; it actually says very little about metaclasses, beyond just the fact that they exist (and even then only mentions class metaclasses). To somewhat see where I came from in this, pdd15 has a =head3 section titled Class Methods, where all of the methods appear to be operations on classes, as opposed to instances of the class. There's also a line in pdd15 that reads: =item - Classes are instances of a meta-class and have their own sets of class methods and class attributes So, I was wondering how one would create a class method. The particular instance I'm looking at is a CStr class for Perl 6, where I want the get_string vtable function for the CStr metaclass instance is different from get_string of a CStr class object. To me, the phrases CStr metaclass instance and CStr class object sound like the same thing. Did you mean CStr object in the second case? I did. Apologies for the ambiguity. If so, then get_string on the class metaclass would just affect the way the class stringifies, and not any of the instances, but I don't get the point of that. So I'm sure I must be misunderstanding you. Do you have an example? Maybe the perl6 code you mention? Well, after re-reading S12 this evening I've determined that the perl6 example I was thinking of isn't precisely correct for the current spec, and I think it's better not to confuse the issue (or myself) by trying to describe my incorrect example. (Essentially, it had to do with the way the Str class stringifies as opposed to the way a Str object stringifies.) But, I think I have another way to describe what I'm asking. In an earlier message [1] Allison wrote that the 'typeof' operator will now return different values for class objects and instances of the class. For example: $P0 = newclass Foo $P1 = new $P0 $S0 = typeof $P0 # returns Class $S1 = typeof $P1 # returns Foo I was wanting to know how to do something similar, except with get_string instead of typeof. In particular, the example I've been thinking of is: $P0 = get_class Str # get the Str class $P1 = new $P0 # create a Str instance assign $P1, XYZ # give it a value $S0 = $P0 # returns Str $S1 = $P1 # returns XYZ In short, I was wondering how I would get a class to stringify to its name (or possibly some mocked value), while having the instances of that class continue to stringify to their values. As I mentioned above, my re-reading of S12 may make this particular question moot, although it's important to note that Jonathan apparently encountered something like it as well. :-) At any rate, I hope the example here hopes to clear up what I was looking for. And thanks for being so patient as I try to get an accurate description together. :-) Pm [1] http://www.nntp.perl.org/group/perl.perl6.internals/2007/06/msg38608.html
