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 : $name) => sub {
68 unquote_sub($outstanding);
70 $outstanding = "$deferred";
71 $QUOTED{$outstanding} = [ $name, $code, $captures ];
72 weaken($WEAK_REFS{$outstanding} = $deferred);
78 $WEAK_REFS{$sub||''} and $QUOTED{$sub||''};
83 unless ($QUOTED{$sub}[3]) {
84 my ($name, $code, $captures) = @{$QUOTED{$sub}};
88 if (keys %$captures) {
89 $make_sub .= capture_unroll("\$_[1]", $captures, 2);
92 my $o_quoted = perlstring $sub;
95 # disable the 'variable $x will not stay shared' warning since
96 # we're not letting it escape from this scope anyway so there's
97 # nothing trying to share it
98 ? " no warnings 'closure';\n sub ${name} {\n"
99 : " \$Sub::Quote::QUOTED{${o_quoted}}[3] = sub {\n"
102 $make_sub .= " }".($name ? '' : ';')."\n";
104 $make_sub .= " \$Sub::Quote::QUOTED{${o_quoted}}[3] = \\&${name}\n";
106 $make_sub .= "}\n1;\n";
107 $ENV{SUB_QUOTE_DEBUG} && warn $make_sub;
111 local *{$name} if $name;
112 unless (_clean_eval $make_sub, $captures) {
113 die "Eval went very, very wrong:\n\n${make_sub}\n\n$@";
124 Sub::Quote - efficient generation of subroutines via string eval
130 use Sub::Quote qw(quote_sub unquote_sub quoted_from_sub);
132 quote_sub 'Silly::kitty', q{ print "meow" };
134 quote_sub 'Silly::doggy', q{ print "woof" };
138 quote_sub 'Silly::dagron',
139 q{ print ++$sound % 2 ? 'burninate' : 'roar' },
140 { '$sound' => \$sound };
146 Silly->dagron; # burninate
147 Silly->dagron; # roar
148 Silly->dagron; # burninate
152 This package provides performant ways to generate subroutines from strings.
158 my $coderef = quote_sub 'Foo::bar', q{ print $x++ . "\n" }, { '$x' => \0 };
160 Arguments: ?$name, $code, ?\%captures, ?\%options
162 C<$name> is the subroutine where the coderef will be installed.
164 C<$code> is a string that will be turned into code.
166 C<\%captures> is a hashref of variables that will be made available to the
167 code. See the L</SYNOPSIS>'s C<Silly::dagron> for an example using captures.
175 B<Boolean>. Set this option to not install the generated coderef into the
176 passed subroutine name on undefer.
182 my $coderef = unquote_sub $sub;
184 Forcibly replace subroutine with actual code.
186 If $sub is not a quoted sub, this is a no-op.
188 =head2 quoted_from_sub
190 my $data = quoted_from_sub $sub;
192 my ($name, $code, $captures, $compiled_sub) = @$data;
194 Returns original arguments to quote_sub, plus the compiled version if this
195 sub has already been unquoted.
197 Note that $sub can be either the original quoted version or the compiled
198 version for convenience.
202 my $prelude = capture_unroll '$captures', {
207 my $inlined_code = inlinify q{
210 print $x + $y . "\n";
211 }, '$x, $y', $prelude;
213 Takes a string of code, a string of arguments, a string of code which acts as a
214 "prelude", and a B<Boolean> representing whether or not to localize the
217 =head2 capture_unroll
219 my $prelude = capture_unroll '$captures', {
224 Arguments: $from, \%captures, $indent
226 Generates a snippet of code which is suitable to be used as a prelude for
227 L</inlinify>. C<$from> is a string will be used as a hashref in the resulting
228 code. The keys of C<%captures> are the names of the variables and the values
229 are ignored. C<$indent> is the number of spaces to indent the result by.
233 Much of this is just string-based code-generation, and as a result, a few caveats
238 Calling C<return> from a quote_sub'ed sub will not likely do what you intend.
239 Instead of returning from the code you defined in C<quote_sub>, it will return
240 from the overall function it is composited into.
244 quote_sub q{ return 1 if $condition; $morecode }
246 It might turn up in the intended context as follows:
252 return 1 if $condition;
259 Which will obviously return from foo, when all you meant to do was return from
260 the code context in quote_sub and proceed with running important code b.
264 Sub::Quote compiles quoted subs in an environment where C<< use strictures >>
265 is in effect. L<strictures> enables L<strict> and FATAL L<warnings>.
267 The following dies I<< Use of uninitialized value in print... >>
270 quote_sub 'Silly::kitty', q{ print undef };
272 If you need to disable parts of strictures, do it within the quoted sub:
274 quote_sub 'Silly::kitty', q{ no warnings; print undef };
278 See L<Moo> for support and contact information.
282 See L<Moo> for authors.
284 =head1 COPYRIGHT AND LICENSE
286 See L<Moo> for the copyright and license.