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Email: info(at)shadowcat.co.uk

Sat Dec 22 00:30:00 2012

Slides for the talk because at lpw-2011

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Because.

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But
first.

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A word to
our sponsors.

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Bytemark

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Next time,
one slide.

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"Our hosting
is way better
than our
presentations."

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Because.

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Because
Damian said
he'd use it.

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Devel::Declare

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  method foo {

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Original
version

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Trapped sub
calls to
'method'

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  method main {

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  main->method

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  method strict

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argh

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Current
version

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Traps CONST
op construction

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Has to fight
to not match
"method"

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Wins.

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But ew.

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XS

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People get
confused

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Why is
Devel::Declare
better than
a filter?

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Token
sensitivity

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Line
based

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Hmm.

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toke.c

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  newCVREF(0, newGVOP(OP_GV, 0, gv));

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That takes
a reference!

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So ...

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  B::svref_2object(
    $glob_ref
  )->REFCNT;

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Filter::Util::Call

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  if ($line =~ s/method (${name_chars})//) {
    return $1;
  }

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But a filter
is called
until it
returns
a line

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EXCEPT

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  return 0; # eof

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Then we don't
get called
anymore

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  filter_add($self);
  return 0;

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  if ($new_refcount > $orig_refcount) {
    $line =~ s/{/; sub ${name} { my \$self = shift;/;
  }

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  method foo {
    ...
  }

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  method foo; sub foo { my $self = shift;
    ...
  }

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But what
about
method main?

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  sub method (*) {

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* proto
means
glob

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barewords are
allowed for
globs

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  set_prototype(
    \&sub, '*;@'
  );

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  (our $Kw = Filter::Keyword->new(
    parser => {
      target_package => __PACKAGE__,
      keyword_name => 'method',
      parser => $parser,
    },
  ))->install;

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  sub {
    my $obj = shift;
    if (my ($stripped, $matches) = $obj->match_source('', '{')) {
      my $name = $obj->current_match->[0];
      $stripped =~ s/{/; sub ${name} { my \$self = shift;/;
      return ($stripped, 1);
    } else {
      return ('', 1);
    }
  }

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  method main { ref($self) }

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  method main { ref($self) }
  my $x = "method foo bar baz";

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  method main { ref($self) }
  my $x = "method foo bar baz";
  warn __PACKAGE__->main;

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  main at t/simple.t line 30

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Keywords ...
in pure perl.

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Now we can
write
MooX::Declare!

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Filter::Keyword

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Filter::Keyword
git://git.shadowcat.co.uk/p5sagit/Filter-Keyword.git

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Don't do
anything
Damian
wouldn't do.

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Thank You
IRC:mst
mst@shadowcat.co.uk
@shadowcat_mst