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1 | package Sub::Quote; |
2 | |
3 | use strictures 1; |
4 | |
5 | sub _clean_eval { eval $_[0] } |
6 | |
7 | use Sub::Defer; |
8 | use B 'perlstring'; |
9 | use base qw(Exporter); |
10 | |
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11 | our @EXPORT = qw(quote_sub unquote_sub quoted_from_sub); |
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12 | |
13 | our %QUOTE_OUTSTANDING; |
14 | |
15 | our %QUOTED; |
16 | |
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17 | sub capture_unroll { |
18 | my ($from, $captures, $indent) = @_; |
19 | join( |
20 | '', |
21 | map { |
22 | /^([\@\%\$])/ |
17a8e3f0 |
23 | or die "capture key should start with \@, \% or \$: $_"; |
8c6626cf |
24 | (' ' x $indent).qq{my ${_} = ${1}{${from}->{${\perlstring $_}}};\n}; |
25 | } keys %$captures |
26 | ); |
27 | } |
28 | |
e57f338d |
29 | sub inlinify { |
30 | my ($code, $args, $extra, $local) = @_; |
31 | my $do = 'do { '.($extra||''); |
32 | if (my ($code_args, $body) = $code =~ / +my \(([^)]+)\) = \@_;(.*)$/s) { |
33 | if ($code_args eq $args) { |
34 | $do.$body.' }' |
35 | } else { |
f537c364 |
36 | $do.'my ('.$code_args.') = ('.$args.'); '.$body.' }'; |
e57f338d |
37 | } |
38 | } else { |
39 | $do.($local ? 'local ' : '').'@_ = ('.$args.'); '.$code.' }'; |
40 | } |
41 | } |
42 | |
a165a07f |
43 | sub _unquote_all_outstanding { |
44 | return unless %QUOTE_OUTSTANDING; |
45 | my ($assembled_code, @assembled_captures, @localize_these) = ''; |
6d377074 |
46 | # we sort the keys in order to make debugging more predictable |
47 | foreach my $outstanding (sort keys %QUOTE_OUTSTANDING) { |
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48 | my ($name, $code, $captures) = @{$QUOTE_OUTSTANDING{$outstanding}}; |
49 | |
50 | push @localize_these, $name if $name; |
51 | |
52 | my $make_sub = "{\n"; |
53 | |
54 | if (keys %$captures) { |
55 | my $ass_cap_count = @assembled_captures; |
8c6626cf |
56 | $make_sub .= capture_unroll("\$_[1][${ass_cap_count}]", $captures, 2); |
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57 | push @assembled_captures, $captures; |
58 | } |
59 | |
60 | my $o_quoted = perlstring $outstanding; |
61 | $make_sub .= ( |
62 | $name |
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63 | # disable the 'variable $x will not stay shared' warning since |
64 | # we're not letting it escape from this scope anyway so there's |
65 | # nothing trying to share it |
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66 | ? " no warnings 'closure';\n sub ${name} {\n" |
934ea2c1 |
67 | : " \$Sub::Quote::QUOTED{${o_quoted}}[3] = sub {\n" |
a165a07f |
68 | ); |
69 | $make_sub .= $code; |
70 | $make_sub .= " }".($name ? '' : ';')."\n"; |
71 | if ($name) { |
72 | $make_sub .= " \$Sub::Quote::QUOTED{${o_quoted}}[3] = \\&${name}\n"; |
73 | } |
74 | $make_sub .= "}\n"; |
75 | $assembled_code .= $make_sub; |
76 | } |
a16d301e |
77 | my $debug_code = $assembled_code; |
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78 | if (@localize_these) { |
a16d301e |
79 | $debug_code = |
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80 | "# localizing: ".join(', ', @localize_these)."\n" |
81 | .$assembled_code; |
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82 | $assembled_code = join("\n", |
83 | (map { "local *${_};" } @localize_these), |
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84 | 'eval '.perlstring($assembled_code).'; die $@ if $@;' |
a165a07f |
85 | ); |
e8b2bab6 |
86 | } else { |
87 | $ENV{SUB_QUOTE_DEBUG} && warn $assembled_code; |
a165a07f |
88 | } |
a16d301e |
89 | $assembled_code .= "\n1;"; |
90 | unless (_clean_eval $assembled_code, \@assembled_captures) { |
91 | die "Eval went very, very wrong:\n\n${debug_code}\n\n$@"; |
a165a07f |
92 | } |
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93 | $ENV{SUB_QUOTE_DEBUG} && warn $debug_code; |
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94 | %QUOTE_OUTSTANDING = (); |
95 | } |
96 | |
97 | sub quote_sub { |
98 | # HOLY DWIMMERY, BATMAN! |
6f68f022 |
99 | # $name => $code => \%captures => \%options |
a165a07f |
100 | # $name => $code => \%captures |
101 | # $name => $code |
6f68f022 |
102 | # $code => \%captures => \%options |
a165a07f |
103 | # $code |
6f68f022 |
104 | my $options = |
105 | (ref($_[-1]) eq 'HASH' and ref($_[-2]) eq 'HASH') |
106 | ? pop |
107 | : {}; |
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108 | my $captures = pop if ref($_[-1]) eq 'HASH'; |
625d6219 |
109 | undef($captures) if $captures && !keys %$captures; |
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110 | my $code = pop; |
111 | my $name = $_[0]; |
112 | my $outstanding; |
6f68f022 |
113 | my $deferred = defer_sub +($options->{no_install} ? undef : $name) => sub { |
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114 | unquote_sub($outstanding); |
115 | }; |
116 | $outstanding = "$deferred"; |
117 | $QUOTE_OUTSTANDING{$outstanding} = $QUOTED{$outstanding} = [ |
118 | $name, $code, $captures |
119 | ]; |
120 | return $deferred; |
121 | } |
122 | |
123 | sub quoted_from_sub { |
124 | my ($sub) = @_; |
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125 | $QUOTED{$sub||''}; |
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126 | } |
127 | |
128 | sub unquote_sub { |
129 | my ($sub) = @_; |
130 | _unquote_all_outstanding; |
131 | $QUOTED{$sub}[3]; |
132 | } |
133 | |
134 | 1; |
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135 | |
0b6e5fff |
136 | =head1 NAME |
137 | |
138 | Sub::Quote - efficient generation of subroutines via string eval |
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139 | |
140 | =head1 SYNOPSIS |
141 | |
142 | package Silly; |
143 | |
144 | use Sub::Quote qw(quote_sub unquote_sub quoted_from_sub); |
145 | |
146 | quote_sub 'Silly::kitty', q{ print "meow" }; |
147 | |
148 | quote_sub 'Silly::doggy', q{ print "woof" }; |
149 | |
150 | my $sound; $$sound = 0; |
151 | |
152 | quote_sub 'Silly::dagron', |
153 | q{ print ++$$sound % 2 ? 'burninate' : 'roar' }, |
154 | { '$sound' => \$sound }; |
155 | |
156 | And elsewhere: |
157 | |
158 | Silly->kitty; # meow |
159 | Silly->doggy; # woof |
160 | Silly->dagron; # burninate |
161 | Silly->dagron; # roar |
162 | Silly->dagron; # burninate |
163 | |
164 | =head1 DESCRIPTION |
165 | |
166 | This package provides performant ways to generate subroutines from strings. |
167 | |
168 | =head1 SUBROUTINES |
169 | |
170 | =head2 quote_sub |
171 | |
172 | my $coderef = quote_sub 'Foo:bar', q{ print $x++ . "\n" }, { '$x' => \0 }; |
173 | |
174 | Arguments: ?$name, $code, ?\%captures, ?\%options |
175 | |
176 | C<$name> is the subroutine where the coderef will be installed. |
177 | |
178 | C<$code> is a string that will be turned into code. |
179 | |
180 | C<\%captures> is a hashref of variables that will be made available to the |
181 | code. See the L</SYNOPSIS>'s C<Silly::dagron> for an example using captures. |
182 | |
183 | =head3 options |
184 | |
185 | =over 2 |
186 | |
187 | =item * no_install |
188 | |
189 | B<Boolean>. Set this option to not install the generated coderef into the |
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190 | passed subroutine name on undefer. |
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191 | |
192 | =back |
193 | |
194 | =head2 unquote_sub |
195 | |
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196 | my $coderef = unquote_sub $sub; |
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197 | |
198 | Forcibly replace subroutine with actual code. Note that as many subs are |
199 | unquoted at a time for performance reasons. This means that if you have a |
200 | syntax error in one of your quoted subs you may find out when some other sub |
201 | is unquoted. |
202 | |
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203 | If $sub is not a quoted sub, this is a no-op. |
204 | |
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205 | =head2 quoted_from_sub |
206 | |
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207 | my $data = quoted_from_sub $sub; |
208 | |
209 | my ($name, $code, $captures, $compiled_sub) = @$data; |
210 | |
211 | Returns original arguments to quote_sub, plus the compiled version if this |
212 | sub has already been unquoted. |
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213 | |
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214 | Note that $sub can be either the original quoted version or the compiled |
215 | version for convenience. |
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216 | |
217 | =head2 inlinify |
218 | |
219 | my $prelude = capture_unroll { |
220 | '$x' => 1, |
221 | '$y' => 2, |
222 | }; |
223 | |
224 | my $inlined_code = inlinify q{ |
225 | my ($x, $y) = @_; |
226 | |
227 | print $x + $y . "\n"; |
228 | }, '$x, $y', $prelude; |
229 | |
230 | Takes a string of code, a string of arguments, a string of code which acts as a |
231 | "prelude", and a B<Boolean> representing whether or not to localize the |
232 | arguments. |
233 | |
234 | =head2 capture_unroll |
235 | |
236 | my $prelude = capture_unroll { |
237 | '$x' => 1, |
238 | '$y' => 2, |
239 | }; |
240 | |
241 | Generates a snippet of code which is suitable to be used as a prelude for |
242 | L</inlinify>. The keys are the names of the variables and the values are (duh) |
243 | the values. Note that references work as values. |