1Eval::WithLexicals(3) User Contributed Perl DocumentationEval::WithLexicals(3)
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NAME

6       Eval::WithLexicals - pure perl eval with persistent lexical variables
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SYNOPSIS

9         # file: bin/tinyrepl
10
11         #!/usr/bin/env perl
12
13         use strictures 1;
14         use Eval::WithLexicals;
15         use Term::ReadLine;
16         use Data::Dumper;
17         use Getopt::Long;
18
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;
33
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         $
56

METHODS

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         );
65
66   eval
67         my @return_value = $eval->eval($code_to_eval);
68
69   lexicals
70         my $current_lexicals = $eval->lexicals;
71
72         $eval->lexicals(\%new_lexicals);
73
74   in_package
75         my $current_package = $eval->in_package;
76
77         $eval->in_package($new_package);
78
79   context
80         my $current_context = $eval->context;
81
82         $eval->context($new_context); # 'list', 'scalar' or 'void'
83
84   prelude
85       Code to run before evaling code. Loads strictures by default.
86
87         my $current_prelude = $eval->prelude;
88
89         $eval->prelude(q{use warnings}); # only warnings, not strict.
90
91   with_plugins
92         my $eval = Eval::WithLexicals->with_plugins("HintPersistence")->new;
93
94       Construct a class with the given plugins. Plugins are roles located
95       under a package name like "Eval::WithLexicals::With*".
96
97       Current plugins are:
98
99       •   HintPersistence
100
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

AUTHOR

107       Matt S. Trout <mst@shadowcat.co.uk>
108

CONTRIBUTORS

110       David Leadbeater <dgl@dgl.cx>
111
112       haarg - Graham Knop (cpan:HAARG) <haarg@cpan.org>
113

115       Copyright (c) 2010 the Eval::WithLexicals "AUTHOR" and "CONTRIBUTORS"
116       as listed above.
117

LICENSE

119       This library is free software and may be distributed under the same
120       terms as perl itself.
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124perl v5.34.0                      2022-01-21             Eval::WithLexicals(3)
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