NAME

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

SYNOPSIS

  # file: bin/tinyrepl

  #!/usr/bin/env perl

  use strictures 1;
  use Eval::WithLexicals;
  use Term::ReadLine;
  use Data::Dumper;
  use Getopt::Long;

  GetOptions(
    "plugin=s" => \my @plugins
  );

  $SIG{INT} = sub { warn "SIGINT\n" };

  { package Data::Dumper; no strict 'vars';
    $Terse = $Indent = $Useqq = $Deparse = $Sortkeys = 1;
    $Quotekeys = 0;
  }

  my $eval = @plugins
   ? Eval::WithLexicals->with_plugins(@plugins)->new
   : Eval::WithLexicals->new;

  my $read = Term::ReadLine->new('Perl REPL');
  while (1) {
    my $line = $read->readline('re.pl$ ');
    exit unless defined $line;
    my @ret; eval {
      local $SIG{INT} = sub { die "Caught SIGINT" };
      @ret = $eval->eval($line); 1;
    } or @ret = ("Error!", $@);
    print Dumper @ret;
  }

  # shell session:

  $ perl -Ilib bin/tinyrepl 
  re.pl$ my $x = 0;
  0
  re.pl$ ++$x;
  1
  re.pl$ $x + 3;
  4
  re.pl$ ^D
  $

METHODS

new

  my $eval = Eval::WithLexicals->new(
    lexicals => { '$x' => \1 },      # default {}
    in_package => 'PackageToEvalIn', # default Eval::WithLexicals::Scratchpad
    context => 'scalar',             # default 'list'
    prelude => 'use warnings',       # default 'use strictures 1'
  );

eval

  my @return_value = $eval->eval($code_to_eval);

lexicals

  my $current_lexicals = $eval->lexicals;

  $eval->lexicals(\%new_lexicals);

in_package

  my $current_package = $eval->in_package;

  $eval->in_package($new_package);

context

  my $current_context = $eval->context;

  $eval->context($new_context); # 'list', 'scalar' or 'void'

prelude

Code to run before evaling code. Loads strictures by default.

  my $current_prelude = $eval->prelude;

  $eval->prelude(q{use warnings}); # only warnings, not strict.

with_plugins

  my $eval = Eval::WithLexicals->with_plugins("HintPersistence")->new;

Construct a class with the given plugins. Plugins are roles located under a package name like "Eval::WithLexicals::With*".

Current plugins are:

•: HintPersistence
When enabled this will persist pragams and other compile hints between evals (for example the strict and warnings flags in effect). See Eval::WithLexicals::WithHintPersistence for further details.

AUTHOR

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

CONTRIBUTORS

David Leadbeater <dgl@dgl.cx>

haarg - Graham Knop (cpan:HAARG) <haarg@cpan.org>

COPYRIGHT

LICENSE

This library is free software and may be distributed under the same terms as perl itself.