5 sub _clean_eval { eval $_[0] }
9 use Scalar::Util qw(weaken);
10 use base qw(Exporter);
12 our $VERSION = '1.003000';
13 $VERSION = eval $VERSION;
15 our @EXPORT = qw(quote_sub unquote_sub quoted_from_sub);
22 my ($from, $captures, $indent) = @_;
27 or die "capture key should start with \@, \% or \$: $_";
28 (' ' x $indent).qq{my ${_} = ${1}{${from}->{${\perlstring $_}}};\n};
34 my ($code, $args, $extra, $local) = @_;
35 my $do = 'do { '.($extra||'');
36 if (my ($code_args, $body) = $code =~ / +my \(([^)]+)\) = \@_;(.*)$/s) {
37 if ($code_args eq $args) {
40 $do.'my ('.$code_args.') = ('.$args.'); '.$body.' }';
44 if ($local || $args ne '@_') {
45 $assign = ($local ? 'local ' : '').'@_ = ('.$args.'); ';
47 $do.$assign.$code.' }';
52 # HOLY DWIMMERY, BATMAN!
53 # $name => $code => \%captures => \%options
54 # $name => $code => \%captures
56 # $code => \%captures => \%options
59 (ref($_[-1]) eq 'HASH' and ref($_[-2]) eq 'HASH')
62 my $captures = pop if ref($_[-1]) eq 'HASH';
63 undef($captures) if $captures && !keys %$captures;
67 my $deferred = defer_sub +($options->{no_install} ? undef : $name) => sub {
68 unquote_sub($quoted_info->[4]);
70 $quoted_info = [ $name, $code, $captures, undef, $deferred ];
71 weaken($QUOTED{$deferred} = $quoted_info);
82 unless ($QUOTED{$sub}[3]) {
83 my ($name, $code, $captures) = @{$QUOTED{$sub}};
87 my %captures = $captures ? %$captures : ();
88 $captures{'$_QUOTED'} = \$QUOTED{$sub};
89 $make_sub .= capture_unroll("\$_[1]", \%captures, 2);
93 # disable the 'variable $x will not stay shared' warning since
94 # we're not letting it escape from this scope anyway so there's
95 # nothing trying to share it
96 ? " no warnings 'closure';\n sub ${name} {\n"
97 : " \$_QUOTED->[3] = sub {\n"
100 $make_sub .= " }".($name ? '' : ';')."\n";
102 $make_sub .= " \$_QUOTED->[3] = \\&${name}\n";
104 $make_sub .= "}\n1;\n";
105 $ENV{SUB_QUOTE_DEBUG} && warn $make_sub;
109 local *{$name} if $name;
110 unless (_clean_eval $make_sub, \%captures) {
111 die "Eval went very, very wrong:\n\n${make_sub}\n\n$@";
119 %QUOTED = map { defined $_ ? ($_->[4] => $_) : () } values %QUOTED;
120 weaken($_) for values %QUOTED;
127 Sub::Quote - efficient generation of subroutines via string eval
133 use Sub::Quote qw(quote_sub unquote_sub quoted_from_sub);
135 quote_sub 'Silly::kitty', q{ print "meow" };
137 quote_sub 'Silly::doggy', q{ print "woof" };
141 quote_sub 'Silly::dagron',
142 q{ print ++$sound % 2 ? 'burninate' : 'roar' },
143 { '$sound' => \$sound };
149 Silly->dagron; # burninate
150 Silly->dagron; # roar
151 Silly->dagron; # burninate
155 This package provides performant ways to generate subroutines from strings.
161 my $coderef = quote_sub 'Foo::bar', q{ print $x++ . "\n" }, { '$x' => \0 };
163 Arguments: ?$name, $code, ?\%captures, ?\%options
165 C<$name> is the subroutine where the coderef will be installed.
167 C<$code> is a string that will be turned into code.
169 C<\%captures> is a hashref of variables that will be made available to the
170 code. See the L</SYNOPSIS>'s C<Silly::dagron> for an example using captures.
178 B<Boolean>. Set this option to not install the generated coderef into the
179 passed subroutine name on undefer.
185 my $coderef = unquote_sub $sub;
187 Forcibly replace subroutine with actual code.
189 If $sub is not a quoted sub, this is a no-op.
191 =head2 quoted_from_sub
193 my $data = quoted_from_sub $sub;
195 my ($name, $code, $captures, $compiled_sub) = @$data;
197 Returns original arguments to quote_sub, plus the compiled version if this
198 sub has already been unquoted.
200 Note that $sub can be either the original quoted version or the compiled
201 version for convenience.
205 my $prelude = capture_unroll '$captures', {
210 my $inlined_code = inlinify q{
213 print $x + $y . "\n";
214 }, '$x, $y', $prelude;
216 Takes a string of code, a string of arguments, a string of code which acts as a
217 "prelude", and a B<Boolean> representing whether or not to localize the
220 =head2 capture_unroll
222 my $prelude = capture_unroll '$captures', {
227 Arguments: $from, \%captures, $indent
229 Generates a snippet of code which is suitable to be used as a prelude for
230 L</inlinify>. C<$from> is a string will be used as a hashref in the resulting
231 code. The keys of C<%captures> are the names of the variables and the values
232 are ignored. C<$indent> is the number of spaces to indent the result by.
236 Much of this is just string-based code-generation, and as a result, a few caveats
241 Calling C<return> from a quote_sub'ed sub will not likely do what you intend.
242 Instead of returning from the code you defined in C<quote_sub>, it will return
243 from the overall function it is composited into.
247 quote_sub q{ return 1 if $condition; $morecode }
249 It might turn up in the intended context as follows:
255 return 1 if $condition;
262 Which will obviously return from foo, when all you meant to do was return from
263 the code context in quote_sub and proceed with running important code b.
267 Sub::Quote compiles quoted subs in an environment where C<< use strictures >>
268 is in effect. L<strictures> enables L<strict> and FATAL L<warnings>.
270 The following dies I<< Use of uninitialized value in print... >>
273 quote_sub 'Silly::kitty', q{ print undef };
275 If you need to disable parts of strictures, do it within the quoted sub:
277 quote_sub 'Silly::kitty', q{ no warnings; print undef };
281 See L<Moo> for support and contact information.
285 See L<Moo> for authors.
287 =head1 COPYRIGHT AND LICENSE
289 See L<Moo> for the copyright and license.