6 use 5.008001; # backwards compat, doesn't warn like 5.8.1
8 our $VERSION = '1.003014';
10 use Devel::REPL::Error;
11 use Scalar::Util qw/blessed/;
12 use Module::Runtime ();
15 my ($self, $plugin) = @_;
16 $plugin = "Devel::REPL::Plugin::$plugin";
17 Module::Runtime::use_module("$plugin");
18 if (my $pre = $plugin->can('BEFORE_PLUGIN')) {
19 $pre->($self, $plugin);
21 Moo::Role->apply_roles_to_package(
22 'Devel::REPL', $plugin
24 if (my $pre = $plugin->can('AFTER_PLUGIN')) {
25 $pre->($self, $plugin);
30 is => 'rw', required => 1,
31 default => sub { Term::ReadLine->new('Perl REPL') }
35 is => 'rw', required => 1,
36 default => sub { '$ ' }
40 is => 'rw', required => 1, lazy => 1,
41 default => sub { shift->term->OUT || \*STDOUT; }
45 is => 'rw', required => 1,
51 while ($self->run_once_safely) {
52 # keep looping unless we want to exit REPL
53 last if $self->exit_repl;
58 my ($self, @args) = @_;
60 my $ret = eval { $self->run_once(@args) };
64 eval { $self->print("Error! - $error\n"); };
74 my $line = $self->read;
75 return unless defined($line); # undefined value == EOF
77 my @ret = $self->formatted_eval($line);
79 $self->print(@ret) unless $self->exit_repl;
85 my ( $self, @args ) = @_;
87 my @ret = $self->eval(@args);
89 return $self->format(@ret);
93 my ( $self, @stuff ) = @_;
95 if ( $self->is_error($stuff[0]) ) {
96 return $self->format_error(@stuff);
98 return $self->format_result(@stuff);
103 my ( $self, @stuff ) = @_;
109 my ( $self, $error ) = @_;
110 return $error->stringify;
114 my ( $self, $thingy ) = @_;
115 blessed($thingy) and $thingy->isa("Devel::REPL::Error");
120 return $self->term->readline($self->prompt);
124 my ($self, $line) = @_;
125 my $compiled = $self->compile($line);
126 return $compiled unless defined($compiled) and not $self->is_error($compiled);
127 return $self->execute($compiled);
131 my ( $_REPL, @args ) = @_;
132 my $compiled = eval $_REPL->wrap_as_sub(@args);
133 return $_REPL->error_return("Compile error", $@) if $@;
138 my ($self, $line, %args) = @_;
139 return qq!sub {\n!. ( $args{no_mangling} ? $line : $self->mangle_line($line) ).qq!\n}\n!;
143 my ($self, $line) = @_;
148 my ($self, $to_exec, @args) = @_;
149 my @ret = eval { $to_exec->(@args) };
150 return $self->error_return("Runtime error", $@) if $@;
155 my ($self, $type, $error) = @_;
156 return Devel::REPL::Error->new( type => $type, message => $error );
160 my ($self, @ret) = @_;
161 my $fh = $self->out_fh;
162 no warnings 'uninitialized';
164 print $fh "\n" if $self->term->ReadLine =~ /Gnu/;
169 Devel::REPL - a modern perl interactive shell
173 my $repl = Devel::REPL->new;
174 $repl->load_plugin($_) for qw(History LexEnv);
177 Alternatively, use the 're.pl' script installed with the distribution
183 This is an interactive shell for Perl, commonly known as a REPL - Read,
184 Evaluate, Print, Loop. The shell provides for rapid development or testing
185 of code without the need to create a temporary source code file.
187 Through a plugin system, many features are available on demand. You can also
188 tailor the environment through the use of profiles and run control files, for
189 example to pre-load certain Perl modules when working on a particular project.
193 To start a shell, follow one of the examples in the L</"SYNOPSIS"> above.
195 Once running, the shell accepts and will attempt to execute any code given. If
196 the code executes successfully you'll be shown the result, otherwise an error
197 message will be returned. Here are a few examples:
199 $_ print "Hello, world!\n"
203 Compile error: Bareword "nosuchfunction" not allowed while "strict subs" in use at (eval 130) line 5.
207 In the first example above you see the output of the command (C<Hello,
208 world!>), if any, and then the return value of the statement (C<1>). Following
209 that example, an error is returned when the execution of some code fails.
211 Note that the lack of semicolon on the end is not a mistake - the code is
212 run inside a Block structure (to protect the REPL in case the code blows up),
213 which means a single statement doesn't require the semicolon. You can add one
216 If you followed the first example in the L</"SYNOPSIS"> above, you'll have the
217 History and LexEnv plugins loaded (and there are many more available).
218 Although the shell might support "up-arrow" history, the History plugin adds
219 "bang" history to that so you can re-execute chosen commands (with e.g.
220 C<!53>). The LexEnv plugin ensures that lexical variables declared with the
221 C<my> keyword will automatically persist between statements executed in the
224 When you C<use> any Perl module, the C<import()> will work as expected - the
225 exported functions from that module are available for immediate use:
227 $_ carp "I'm dieeeing!\n"
228 String found where operator expected at (eval 129) line 5, near "carp "I'm dieeeing!\n""
229 (Do you need to predeclare carp?)
230 Compile error: syntax error at (eval 129) line 5, near "carp "I'm dieeeing!\n""
231 BEGIN not safe after errors--compilation aborted at (eval 129) line 5.
235 $_ carp "I'm dieeeing!\n"
237 at /usr/share/perl5/Lexical/Persistence.pm line 327
241 To quit from the shell, hit C<Ctrl+D> or C<Ctrl+C>.
243 MSWin32 NOTE: control keys won't work if TERM=dumb
244 because readline functionality will be disabled.
247 =head2 Run Control Files
249 For particular projects you might well end up running the same commands each
250 time the REPL shell starts up - loading Perl modules, setting configuration,
251 and so on. A run control file lets you have this done automatically, and you
252 can have multiple files for different projects.
254 By default the C<re.pl> program looks for C<< $HOME/.re.pl/repl.rc >>, and
255 runs whatever code is in there as if you had entered it at the REPL shell
258 To set a new run control file that's also in that directory, pass it as a
261 system$ re.pl --rcfile myproject.pc
263 If the filename happens to contain a forwardslash, then it's used absolutely,
264 or realive to the current working directory:
266 system$ re.pl --rcfile /path/to/my/project/repl.rc
268 Within the run control file you might want to load plugins. This is covered in
269 L</"The REPL shell object"> section, below.
273 To allow for the sharing of run control files, you can fashion them into a
274 Perl module for distribution (perhaps via the CPAN). For more information on
275 this feature, please see the L<Devel::REPL::Profile> manual page.
277 A default profile ships with C<Devel::REPL>; it loads the following plugins:
283 L<Devel::REPL::Plugin::History>
287 L<Devel::REPL::Plugin::LexEnv>
291 L<Devel::REPL::Plugin::DDS>
295 L<Devel::REPL::Plugin::Packages>
299 L<Devel::REPL::Plugin::Commands>
303 L<Devel::REPL::Plugin::MultiLine::PPI>
307 L<Devel::REPL::Plugin::Colors>
311 L<Devel::REPL::Plugin::Completion>
315 L<Devel::REPL::Plugin::CompletionDriver::INC>
319 L<Devel::REPL::Plugin::CompletionDriver::LexEnv>
323 L<Devel::REPL::Plugin::CompletionDriver::Keywords>
327 L<Devel::REPL::Plugin::CompletionDriver::Methods>
331 L<Devel::REPL::Plugin::ReadlineHistory>
337 Plugins are a way to add funcionality to the REPL shell, and take advantage of
338 C<Devel::REPL> being based on the L<Moose> object system for Perl 5. This
339 means it's simple to 'hook into' many steps of the R-E-P-L process. Plugins
340 can change the way commands are interpreted, or the way their results are
341 output, or even add commands to the shell environment.
343 A number of plugins ship with C<Devel::REPL>, and more are available on the
344 CPAN. Some of the shipped plugins are loaded in the default profile, mentioned
345 above. These plugins can be loaded in your C<< $HOME/.re.pl/repl.rc >> like:
347 load_plugin qw( CompletionDriver::Global DumpHistory );
349 Writing your own plugins is not difficult, and is discussed in the
350 L<Devel::REPL::Plugin> manual page, along with links to the manual pages of
351 all the plugins shipped with C<Devel::REPL>.
353 =head2 The REPL shell object
355 From time to time you'll want to interact with or manipulate the
356 C<Devel::REPL> shell object itself; that is, the instance of the shell you're
359 The object is always available through the C<$_REPL> variable. One common
360 requirement is to load an additional plugin, after your profile and run
361 control files have already been executed:
363 $_ $_REPL->load_plugin('Timing');
365 $_ print "Hello again, world!\n"
367 Took 0.00148296356201172 seconds.
373 In addition to the contents of the standard Perl distribution, you will need
384 L<MooseX::Getopt> >= 0.18
412 Optionally, some plugins if installed will require the following modules:
422 L<Data::Dump::Streamer>
426 L<Data::Dumper::Concise>
442 L<Lexical::Persistence>
456 Matt S Trout - mst (at) shadowcatsystems.co.uk (L<http://www.shadowcatsystems.co.uk/>)
462 =item Stevan Little - stevan (at) iinteractive.com
464 =item Alexis Sukrieh - sukria+perl (at) sukria.net
468 =item mgrimes - mgrimes (at) cpan dot org
470 =item Shawn M Moore - sartak (at) gmail.com
472 =item Oliver Gorwits - oliver on irc.perl.org
474 =item Andrew Moore - C<< <amoore@cpan.org> >>
476 =item Norbert Buchmuller C<< <norbi@nix.hu> >>
478 =item Dave Houston C<< <dhouston@cpan.org> >>
486 This library is free software under the same terms as perl itself