1Eval::WithLexicals(3) User Contributed Perl DocumentationEval::WithLexicals(3)
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6 Eval::WithLexicals - pure perl eval with persistent lexical variables
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9 # file: bin/tinyrepl
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11 #!/usr/bin/env perl
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13 use strictures 1;
14 use Eval::WithLexicals;
15 use Term::ReadLine;
16 use Data::Dumper;
17 use Getopt::Long;
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19 GetOptions(
20 "plugin=s" => \my @plugins
21 );
22
23 $SIG{INT} = sub { warn "SIGINT\n" };
24
25 { package Data::Dumper; no strict 'vars';
26 $Terse = $Indent = $Useqq = $Deparse = $Sortkeys = 1;
27 $Quotekeys = 0;
28 }
29
30 my $eval = @plugins
31 ? Eval::WithLexicals->with_plugins(@plugins)->new
32 : Eval::WithLexicals->new;
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34 my $read = Term::ReadLine->new('Perl REPL');
35 while (1) {
36 my $line = $read->readline('re.pl$ ');
37 exit unless defined $line;
38 my @ret; eval {
39 local $SIG{INT} = sub { die "Caught SIGINT" };
40 @ret = $eval->eval($line); 1;
41 } or @ret = ("Error!", $@);
42 print Dumper @ret;
43 }
44
45 # shell session:
46
47 $ perl -Ilib bin/tinyrepl
48 re.pl$ my $x = 0;
49 0
50 re.pl$ ++$x;
51 1
52 re.pl$ $x + 3;
53 4
54 re.pl$ ^D
55 $
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58 new
59 my $eval = Eval::WithLexicals->new(
60 lexicals => { '$x' => \1 }, # default {}
61 in_package => 'PackageToEvalIn', # default Eval::WithLexicals::Scratchpad
62 context => 'scalar', # default 'list'
63 prelude => 'use warnings', # default 'use strictures 1'
64 );
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66 eval
67 my @return_value = $eval->eval($code_to_eval);
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69 lexicals
70 my $current_lexicals = $eval->lexicals;
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72 $eval->lexicals(\%new_lexicals);
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74 in_package
75 my $current_package = $eval->in_package;
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77 $eval->in_package($new_package);
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79 context
80 my $current_context = $eval->context;
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82 $eval->context($new_context); # 'list', 'scalar' or 'void'
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84 prelude
85 Code to run before evaling code. Loads strictures by default.
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87 my $current_prelude = $eval->prelude;
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89 $eval->prelude(q{use warnings}); # only warnings, not strict.
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91 with_plugins
92 my $eval = Eval::WithLexicals->with_plugins("HintPersistence")->new;
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94 Construct a class with the given plugins. Plugins are roles located
95 under a package name like "Eval::WithLexicals::With*".
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97 Current plugins are:
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99 ยท HintPersistence
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101 When enabled this will persist pragams and other compile hints
102 between evals (for example the strict and warnings flags in
103 effect). See Eval::WithLexicals::WithHintPersistence for further
104 details.
105
107 Matt S. Trout <mst@shadowcat.co.uk>
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110 David Leadbeater <dgl@dgl.cx>
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112 haarg - Graham Knop (cpan:HAARG) <haarg@cpan.org>
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115 Copyright (c) 2010 the Eval::WithLexicals "AUTHOR" and "CONTRIBUTORS"
116 as listed above.
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119 This library is free software and may be distributed under the same
120 terms as perl itself.
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124perl v5.30.0 2019-07-26 Eval::WithLexicals(3)