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1 | package Eval::WithLexicals; |
2 | |
3 | use Moo; |
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4 | use Moo::Role (); |
5 | use Sub::Quote; |
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6 | |
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7 | our $VERSION = '1.001000'; # 1.1.0 |
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8 | $VERSION = eval $VERSION; |
9 | |
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10 | has lexicals => (is => 'rw', default => quote_sub q{ {} }); |
11 | |
12 | { |
13 | my %valid_contexts = map +($_ => 1), qw(list scalar void); |
14 | |
15 | has context => ( |
16 | is => 'rw', default => quote_sub(q{ 'list' }), |
17 | isa => sub { |
18 | my ($val) = @_; |
19 | die "Invalid context type $val - should be list, scalar or void" |
20 | unless $valid_contexts{$val}; |
21 | }, |
22 | ); |
23 | } |
24 | |
25 | has in_package => ( |
26 | is => 'rw', default => quote_sub q{ 'Eval::WithLexicals::Scratchpad' } |
27 | ); |
28 | |
29 | has prelude => ( |
30 | is => 'rw', default => quote_sub q{ 'use strictures 1;' } |
31 | ); |
32 | |
33 | sub with_plugins { |
34 | my($class, @names) = @_; |
35 | |
36 | Moo::Role->create_class_with_roles($class, |
37 | map "Eval::WithLexicals::With$_", @names); |
38 | } |
39 | |
40 | sub setup_code { |
41 | my($self) = @_; |
42 | $self->prelude; |
43 | } |
44 | |
45 | sub capture_code { |
46 | ( qq{ BEGIN { Eval::WithLexicals::Util::capture_list() } } ) |
47 | } |
48 | |
49 | sub eval { |
50 | my ($self, $to_eval) = @_; |
51 | local *Eval::WithLexicals::Cage::current_line; |
52 | local *Eval::WithLexicals::Cage::pad_capture; |
53 | local *Eval::WithLexicals::Cage::grab_captures; |
54 | |
55 | my $package = $self->in_package; |
56 | my $setup_code = join '', $self->setup_code, |
57 | Sub::Quote::capture_unroll('$_[2]', $self->lexicals, 2); |
58 | |
59 | my $capture_code = join '', $self->capture_code; |
60 | |
61 | local our $current_code = qq! |
62 | ${setup_code} |
63 | sub Eval::WithLexicals::Cage::current_line { |
64 | package ${package}; |
65 | #line 1 "(eval)" |
66 | ${to_eval} |
67 | ;sub Eval::WithLexicals::Cage::pad_capture { } |
68 | ${capture_code} |
69 | sub Eval::WithLexicals::Cage::grab_captures { |
70 | no warnings 'closure'; no strict 'vars'; |
71 | package Eval::WithLexicals::VarScope;!; |
72 | # rest is appended by Eval::WithLexicals::Util::capture_list, called |
73 | # during parsing by the BEGIN block from capture_code. |
74 | |
75 | $self->_eval_do(\$current_code, $self->lexicals, $to_eval); |
76 | $self->_run(\&Eval::WithLexicals::Cage::current_line); |
77 | } |
78 | |
79 | sub _run { |
80 | my($self, $code) = @_; |
81 | |
82 | my @ret; |
83 | my $ctx = $self->context; |
84 | if ($ctx eq 'list') { |
85 | @ret = $code->(); |
86 | } elsif ($ctx eq 'scalar') { |
87 | $ret[0] = $code->(); |
88 | } else { |
89 | $code->(); |
90 | } |
91 | $self->lexicals({ |
92 | %{$self->lexicals}, |
93 | %{$self->_grab_captures}, |
94 | }); |
95 | @ret; |
96 | } |
97 | |
98 | sub _grab_captures { |
99 | my ($self) = @_; |
100 | my $cap = Eval::WithLexicals::Cage::grab_captures(); |
101 | foreach my $key (keys %$cap) { |
102 | my ($sigil, $name) = $key =~ /^(.)(.+)$/; |
103 | my $var_scope_name = $sigil.'Eval::WithLexicals::VarScope::'.$name; |
104 | if ($cap->{$key} eq eval "\\${var_scope_name}") { |
105 | delete $cap->{$key}; |
106 | } |
107 | } |
108 | $cap; |
109 | } |
110 | |
111 | sub _eval_do { |
112 | my ($self, $text_ref, $lexical, $original) = @_; |
113 | local @INC = (sub { |
114 | if ($_[1] eq '/eval_do') { |
115 | open my $fh, '<', $text_ref; |
116 | $fh; |
117 | } else { |
118 | (); |
119 | } |
120 | }, @INC); |
121 | do '/eval_do' or die $@; |
122 | } |
123 | |
124 | { |
125 | package Eval::WithLexicals::Util; |
126 | |
127 | use B qw(svref_2object); |
128 | |
129 | sub capture_list { |
130 | my $pad_capture = \&Eval::WithLexicals::Cage::pad_capture; |
131 | my @names = grep $_ ne '&', map $_->PV, grep $_->isa('B::PV'), |
132 | svref_2object($pad_capture)->OUTSIDE->PADLIST->ARRAYelt(0)->ARRAY; |
133 | $Eval::WithLexicals::current_code .= |
134 | '+{ '.join(', ', map "'$_' => \\$_", @names).' };' |
135 | ."\n}\n}\n1;\n"; |
136 | } |
137 | } |
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138 | |
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139 | =head1 NAME |
140 | |
141 | Eval::WithLexicals - pure perl eval with persistent lexical variables |
142 | |
143 | =head1 SYNOPSIS |
144 | |
145 | # file: bin/tinyrepl |
146 | |
147 | #!/usr/bin/env perl |
148 | |
149 | use strictures 1; |
150 | use Eval::WithLexicals; |
151 | use Term::ReadLine; |
152 | use Data::Dumper; |
153 | |
154 | $SIG{INT} = sub { warn "SIGINT\n" }; |
155 | |
156 | { package Data::Dumper; no strict 'vars'; |
157 | $Terse = $Indent = $Useqq = $Deparse = $Sortkeys = 1; |
158 | $Quotekeys = 0; |
159 | } |
160 | |
161 | my $eval = Eval::WithLexicals->new; |
162 | my $read = Term::ReadLine->new('Perl REPL'); |
163 | while (1) { |
164 | my $line = $read->readline('re.pl$ '); |
165 | exit unless defined $line; |
166 | my @ret; eval { |
167 | local $SIG{INT} = sub { die "Caught SIGINT" }; |
168 | @ret = $eval->eval($line); 1; |
169 | } or @ret = ("Error!", $@); |
170 | print Dumper @ret; |
171 | } |
172 | |
173 | # shell session: |
174 | |
175 | $ perl -Ilib bin/tinyrepl |
176 | re.pl$ my $x = 0; |
177 | 0 |
178 | re.pl$ ++$x; |
179 | 1 |
180 | re.pl$ $x + 3; |
181 | 4 |
182 | re.pl$ ^D |
183 | $ |
184 | |
185 | =head1 METHODS |
186 | |
187 | =head2 new |
188 | |
189 | my $eval = Eval::WithLexicals->new( |
190 | lexicals => { '$x' => \1 }, # default {} |
191 | in_package => 'PackageToEvalIn', # default Eval::WithLexicals::Scratchpad |
192 | context => 'scalar', # default 'list' |
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193 | prelude => 'use warnings', # default 'use strictures 1' |
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194 | ); |
195 | |
196 | =head2 eval |
197 | |
198 | my @return_value = $eval->eval($code_to_eval); |
199 | |
200 | =head2 lexicals |
201 | |
202 | my $current_lexicals = $eval->lexicals; |
203 | |
204 | $eval->lexicals(\%new_lexicals); |
205 | |
206 | =head2 in_package |
207 | |
208 | my $current_package = $eval->in_package; |
209 | |
210 | $eval->in_package($new_package); |
211 | |
212 | =head2 context |
213 | |
214 | my $current_context = $eval->context; |
215 | |
216 | $eval->context($new_context); # 'list', 'scalar' or 'void' |
217 | |
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218 | =head2 prelude |
219 | |
220 | Code to run before evaling code. Loads L<strictures> by default. |
221 | |
222 | my $current_prelude = $eval->prelude; |
223 | |
224 | $eval->prelude(q{use warnings}); # only warnings, not strict. |
225 | |
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226 | =head1 AUTHOR |
227 | |
228 | Matt S. Trout <mst@shadowcat.co.uk> |
229 | |
230 | =head1 CONTRIBUTORS |
231 | |
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232 | David Leadbeater <dgl@dgl.cx> |
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233 | |
234 | =head1 COPYRIGHT |
235 | |
236 | Copyright (c) 2010 the Eval::WithLexicals L</AUTHOR> and L</CONTRIBUTORS> |
237 | as listed above. |
238 | |
239 | =head1 LICENSE |
240 | |
241 | This library is free software and may be distributed under the same terms |
242 | as perl itself. |
243 | |
244 | =cut |
245 | |
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246 | 1; |