use Sub::Defer;
use B 'perlstring';
+use Scalar::Util qw(weaken);
use base qw(Exporter);
-our @EXPORT = qw(quote_sub unquote_sub);
+our @EXPORT = qw(quote_sub unquote_sub quoted_from_sub);
our %QUOTE_OUTSTANDING;
our %QUOTED;
+our %WEAK_REFS;
+
+sub capture_unroll {
+ my ($from, $captures, $indent) = @_;
+ join(
+ '',
+ map {
+ /^([\@\%\$])/
+ or die "capture key should start with \@, \% or \$: $_";
+ (' ' x $indent).qq{my ${_} = ${1}{${from}->{${\perlstring $_}}};\n};
+ } keys %$captures
+ );
+}
+
+sub inlinify {
+ my ($code, $args, $extra, $local) = @_;
+ my $do = 'do { '.($extra||'');
+ if (my ($code_args, $body) = $code =~ / +my \(([^)]+)\) = \@_;(.*)$/s) {
+ if ($code_args eq $args) {
+ $do.$body.' }'
+ } else {
+ $do.'my ('.$code_args.') = ('.$args.'); '.$body.' }';
+ }
+ } else {
+ $do.($local ? 'local ' : '').'@_ = ('.$args.'); '.$code.' }';
+ }
+}
+
sub _unquote_all_outstanding {
return unless %QUOTE_OUTSTANDING;
my ($assembled_code, @assembled_captures, @localize_these) = '';
- foreach my $outstanding (keys %QUOTE_OUTSTANDING) {
+ # we sort the keys in order to make debugging more predictable
+ foreach my $outstanding (sort keys %QUOTE_OUTSTANDING) {
my ($name, $code, $captures) = @{$QUOTE_OUTSTANDING{$outstanding}};
push @localize_these, $name if $name;
if (keys %$captures) {
my $ass_cap_count = @assembled_captures;
- $make_sub .= join(
- "\n",
- map {
- /^([\@\%\$])/
- or die "capture key should start with \@, \% or \$: $_";
- qq{ my ${_} = ${1}{\$_[1][${ass_cap_count}]{${\perlstring $_}}};\n};
- } keys %$captures
- );
+ $make_sub .= capture_unroll("\$_[1][${ass_cap_count}]", $captures, 2);
push @assembled_captures, $captures;
}
my $o_quoted = perlstring $outstanding;
$make_sub .= (
$name
+ # disable the 'variable $x will not stay shared' warning since
+ # we're not letting it escape from this scope anyway so there's
+ # nothing trying to share it
? " no warnings 'closure';\n sub ${name} {\n"
- : " \$Sub::Quote::QUOTED{${o_quoted}}[3] = sub {\n"
+ : " \$Sub::Quote::QUOTED{${o_quoted}}[3] = sub {\n"
);
$make_sub .= $code;
$make_sub .= " }".($name ? '' : ';')."\n";
$make_sub .= "}\n";
$assembled_code .= $make_sub;
}
+ my $debug_code = $assembled_code;
if (@localize_these) {
+ $debug_code =
+ "# localizing: ".join(', ', @localize_these)."\n"
+ .$assembled_code;
$assembled_code = join("\n",
(map { "local *${_};" } @localize_these),
- 'eval '.perlstring $assembled_code
+ 'eval '.perlstring($assembled_code).'; die $@ if $@;'
);
+ } else {
+ $ENV{SUB_QUOTE_DEBUG} && warn $assembled_code;
}
- $ENV{SUB_QUOTE_DEBUG} && warn $assembled_code;
- _clean_eval $assembled_code, \@assembled_captures;
- if ($@) {
- die "Eval went very, very wrong:\n\n${assembled_code}\n\n$@";
+ $assembled_code .= "\n1;";
+ {
+ local $@;
+ unless (_clean_eval $assembled_code, \@assembled_captures) {
+ die "Eval went very, very wrong:\n\n${debug_code}\n\n$@";
+ }
}
+ $ENV{SUB_QUOTE_DEBUG} && warn $debug_code;
%QUOTE_OUTSTANDING = ();
}
sub quote_sub {
# HOLY DWIMMERY, BATMAN!
+ # $name => $code => \%captures => \%options
# $name => $code => \%captures
# $name => $code
- # $code => \%captures
+ # $code => \%captures => \%options
# $code
+ my $options =
+ (ref($_[-1]) eq 'HASH' and ref($_[-2]) eq 'HASH')
+ ? pop
+ : {};
my $captures = pop if ref($_[-1]) eq 'HASH';
+ undef($captures) if $captures && !keys %$captures;
my $code = pop;
my $name = $_[0];
my $outstanding;
- my $deferred = defer_sub $name => sub {
+ my $deferred = defer_sub +($options->{no_install} ? undef : $name) => sub {
unquote_sub($outstanding);
};
$outstanding = "$deferred";
$QUOTE_OUTSTANDING{$outstanding} = $QUOTED{$outstanding} = [
$name, $code, $captures
];
+ weaken($WEAK_REFS{$outstanding} = $deferred);
return $deferred;
}
sub quoted_from_sub {
my ($sub) = @_;
- $QUOTED{$sub};
+ $WEAK_REFS{$sub||''} and $QUOTED{$sub||''};
}
sub unquote_sub {
}
1;
+
+=head1 NAME
+
+Sub::Quote - efficient generation of subroutines via string eval
+
+=head1 SYNOPSIS
+
+ package Silly;
+
+ use Sub::Quote qw(quote_sub unquote_sub quoted_from_sub);
+
+ quote_sub 'Silly::kitty', q{ print "meow" };
+
+ quote_sub 'Silly::doggy', q{ print "woof" };
+
+ my $sound = 0;
+
+ quote_sub 'Silly::dagron',
+ q{ print ++$sound % 2 ? 'burninate' : 'roar' },
+ { '$sound' => \$sound };
+
+And elsewhere:
+
+ Silly->kitty; # meow
+ Silly->doggy; # woof
+ Silly->dagron; # burninate
+ Silly->dagron; # roar
+ Silly->dagron; # burninate
+
+=head1 DESCRIPTION
+
+This package provides performant ways to generate subroutines from strings.
+
+=head1 SUBROUTINES
+
+=head2 quote_sub
+
+ my $coderef = quote_sub 'Foo::bar', q{ print $x++ . "\n" }, { '$x' => \0 };
+
+Arguments: ?$name, $code, ?\%captures, ?\%options
+
+C<$name> is the subroutine where the coderef will be installed.
+
+C<$code> is a string that will be turned into code.
+
+C<\%captures> is a hashref of variables that will be made available to the
+code. See the L</SYNOPSIS>'s C<Silly::dagron> for an example using captures.
+
+=head3 options
+
+=over 2
+
+=item * no_install
+
+B<Boolean>. Set this option to not install the generated coderef into the
+passed subroutine name on undefer.
+
+=back
+
+=head2 unquote_sub
+
+ my $coderef = unquote_sub $sub;
+
+Forcibly replace subroutine with actual code. Note that for performance
+reasons all quoted subs declared so far will be globally unquoted/parsed in
+a single eval. This means that if you have a syntax error in one of your
+quoted subs you may find out when some other sub is unquoted.
+
+If $sub is not a quoted sub, this is a no-op.
+
+=head2 quoted_from_sub
+
+ my $data = quoted_from_sub $sub;
+
+ my ($name, $code, $captures, $compiled_sub) = @$data;
+
+Returns original arguments to quote_sub, plus the compiled version if this
+sub has already been unquoted.
+
+Note that $sub can be either the original quoted version or the compiled
+version for convenience.
+
+=head2 inlinify
+
+ my $prelude = capture_unroll {
+ '$x' => 1,
+ '$y' => 2,
+ };
+
+ my $inlined_code = inlinify q{
+ my ($x, $y) = @_;
+
+ print $x + $y . "\n";
+ }, '$x, $y', $prelude;
+
+Takes a string of code, a string of arguments, a string of code which acts as a
+"prelude", and a B<Boolean> representing whether or not to localize the
+arguments.
+
+=head2 capture_unroll
+
+ my $prelude = capture_unroll {
+ '$x' => 1,
+ '$y' => 2,
+ };
+
+Generates a snippet of code which is suitable to be used as a prelude for
+L</inlinify>. The keys are the names of the variables and the values are (duh)
+the values. Note that references work as values.
projects / gitmo/Role-Tiny.git / blobdiff