5 use namespace::autoclean;
6 use 5.008001; # backwards compat, doesn't warn like 5.8.1
8 with 'MooseX::Object::Pluggable';
10 use Devel::REPL::Error;
15 default => sub { Term::ReadLine->new('Perl REPL') }
20 default => sub { '$ ' }
26 default => sub { shift->term->OUT || \*STDOUT; }
36 while ($self->run_once_safely) {
37 # keep looping unless we want to exit REPL
38 last if $self->exit_repl;
43 my ($self, @args) = @_;
45 my $ret = eval { $self->run_once(@args) };
49 eval { $self->print("Error! - $error\n"); };
59 my $line = $self->read;
60 return unless defined($line); # undefined value == EOF
62 my @ret = $self->formatted_eval($line);
64 $self->print(@ret) unless $self->exit_repl;
70 my ( $self, @args ) = @_;
72 my @ret = $self->eval(@args);
74 return $self->format(@ret);
78 my ( $self, @stuff ) = @_;
80 if ( $self->is_error($stuff[0]) ) {
81 return $self->format_error(@stuff);
83 return $self->format_result(@stuff);
88 my ( $self, @stuff ) = @_;
94 my ( $self, $error ) = @_;
95 return $error->stringify;
99 my ( $self, $thingy ) = @_;
100 blessed($thingy) and $thingy->isa("Devel::REPL::Error");
105 return $self->term->readline($self->prompt);
109 my ($self, $line) = @_;
110 my $compiled = $self->compile($line);
111 return $compiled unless defined($compiled) and not $self->is_error($compiled);
112 return $self->execute($compiled);
116 my ( $_REPL, @args ) = @_;
117 my $compiled = eval $_REPL->wrap_as_sub(@args);
118 return $_REPL->error_return("Compile error", $@) if $@;
123 my ($self, $line, %args) = @_;
124 return qq!sub {\n!. ( $args{no_mangling} ? $line : $self->mangle_line($line) ).qq!\n}\n!;
128 my ($self, $line) = @_;
133 my ($self, $to_exec, @args) = @_;
134 my @ret = eval { $to_exec->(@args) };
135 return $self->error_return("Runtime error", $@) if $@;
140 my ($self, $type, $error) = @_;
141 return Devel::REPL::Error->new( type => $type, message => $error );
145 my ($self, @ret) = @_;
146 my $fh = $self->out_fh;
147 no warnings 'uninitialized';
149 print $fh "\n" if $self->term->ReadLine =~ /Gnu/;
154 Devel::REPL - A modern perl interactive shell
158 my $repl = Devel::REPL->new;
159 $repl->load_plugin($_) for qw(History LexEnv);
162 Alternatively, use the 're.pl' script installed with the distribution
168 This is an interactive shell for Perl, commonly known as a REPL - Read,
169 Evaluate, Print, Loop. The shell provides for rapid development or testing
170 of code without the need to create a temporary source code file.
172 Through a plugin system, many features are available on demand. You can also
173 tailor the environment through the use of profiles and run control files, for
174 example to pre-load certain Perl modules when working on a particular project.
178 To start a shell, follow one of the examples in the L</"SYNOPSIS"> above.
180 Once running, the shell accepts and will attempt to execute any code given. If
181 the code executes successfully you'll be shown the result, otherwise an error
182 message will be returned. Here are a few examples:
184 $_ print "Hello, world!\n"
188 Compile error: Bareword "nosuchfunction" not allowed while "strict subs" in use at (eval 130) line 5.
192 In the first example above you see the output of the command (C<Hello,
193 world!>), if any, and then the return value of the statement (C<1>). Following
194 that example, an error is returned when the execution of some code fails.
196 Note that the lack of semicolon on the end is not a mistake - the code is
197 run inside a Block structure (to protect the REPL in case the code blows up),
198 which means a single statement doesn't require the semicolon. You can add one
201 If you followed the first example in the L</"SYNOPSIS"> above, you'll have the
202 L<History|Devel::REPL::Plugin::History> and L<LexEnv|Devel::REPL::Plugin::LexEnv>
203 plugins loaded (and there are many more available).
204 Although the shell might support "up-arrow" history, the History plugin adds
205 "bang" history to that so you can re-execute chosen commands (with e.g.
206 C<!53>). The LexEnv plugin ensures that lexical variables declared with the
207 C<my> keyword will automatically persist between statements executed in the
210 When you C<use> any Perl module, the C<import()> will work as expected - the
211 exported functions from that module are available for immediate use:
213 $_ carp "I'm dieeeing!\n"
214 String found where operator expected at (eval 129) line 5, near "carp "I'm dieeeing!\n""
215 (Do you need to predeclare carp?)
216 Compile error: syntax error at (eval 129) line 5, near "carp "I'm dieeeing!\n""
217 BEGIN not safe after errors--compilation aborted at (eval 129) line 5.
221 $_ carp "I'm dieeeing!\n"
223 at /usr/share/perl5/Lexical/Persistence.pm line 327
227 To quit from the shell, hit C<Ctrl+D> or C<Ctrl+C>.
229 MSWin32 NOTE: control keys won't work if TERM=dumb
230 because readline functionality will be disabled.
233 =head2 Run Control Files
235 For particular projects you might well end up running the same commands each
236 time the REPL shell starts up - loading Perl modules, setting configuration,
237 and so on. A run control file lets you have this done automatically, and you
238 can have multiple files for different projects.
240 By default the C<re.pl> program looks for C<< $HOME/.re.pl/repl.rc >>, and
241 runs whatever code is in there as if you had entered it at the REPL shell
244 To set a new run control file that's also in that directory, pass it as a
247 system$ re.pl --rcfile myproject.pc
249 If the filename happens to contain a forward slash, then it's used absolutely,
250 or realive to the current working directory:
252 system$ re.pl --rcfile /path/to/my/project/repl.rc
254 Within the run control file you might want to load plugins. This is covered in
255 L</"The REPL shell object"> section, below.
259 To allow for the sharing of run control files, you can fashion them into a
260 Perl module for distribution (perhaps via the CPAN). For more information on
261 this feature, please see the L<Devel::REPL::Profile> manual page.
263 A C<Standard> profile ships with C<Devel::REPL>; it loads the following plugins
264 (note that some of these require optional features -- or you can also use the
271 L<Devel::REPL::Plugin::History>
275 L<Devel::REPL::Plugin::LexEnv>
279 L<Devel::REPL::Plugin::DDS>
283 L<Devel::REPL::Plugin::Packages>
287 L<Devel::REPL::Plugin::Commands>
291 L<Devel::REPL::Plugin::MultiLine::PPI>
295 L<Devel::REPL::Plugin::Colors>
299 L<Devel::REPL::Plugin::Completion>
303 L<Devel::REPL::Plugin::CompletionDriver::INC>
307 L<Devel::REPL::Plugin::CompletionDriver::LexEnv>
311 L<Devel::REPL::Plugin::CompletionDriver::Keywords>
315 L<Devel::REPL::Plugin::CompletionDriver::Methods>
319 L<Devel::REPL::Plugin::ReadlineHistory>
325 Plugins are a way to add functionality to the REPL shell, and take advantage of
326 C<Devel::REPL> being based on the L<Moose> object system for Perl 5. This
327 means it's simple to 'hook into' many steps of the R-E-P-L process. Plugins
328 can change the way commands are interpreted, or the way their results are
329 output, or even add commands to the shell environment.
331 A number of plugins ship with C<Devel::REPL>, and more are available on the
332 CPAN. Some of the shipped plugins are loaded in the default profile, mentioned
333 above. These plugins can be loaded in your F< $HOME/.re.pl/repl.rc > like:
335 load_plugin qw( CompletionDriver::Global DumpHistory );
337 Writing your own plugins is not difficult, and is discussed in the
338 L<Devel::REPL::Plugin> manual page, along with links to the manual pages of
339 all the plugins shipped with C<Devel::REPL>.
341 =head2 The REPL shell object
343 From time to time you'll want to interact with or manipulate the
344 C<Devel::REPL> shell object itself; that is, the instance of the shell you're
347 The object is always available through the C<$_REPL> variable. One common
348 requirement is to load an additional plugin, after your profile and run
349 control files have already been executed:
351 $_ $_REPL->load_plugin('Timing');
353 $_ print "Hello again, world!\n"
355 Took 0.00148296356201172 seconds.
359 =head1 OPTIONAL FEATURES
361 In addition to the prerequisites declared in this distribution, which should be automatically installed by your L<CPAN> client, there are a number of optional features, used by
362 additional plugins. You can install any of these features by installing this
363 distribution interactively (e.g. C<cpanm --interactive Devel::REPL>).
365 =for comment I hope to automatically generate this data via a Pod::Weaver section
369 =item * Completion plugin - extensible tab completion
371 =item * DDS plugin - better format results with Data::Dump::Streamer
373 =item * DDC plugin - even better format results with Data::Dumper::Concise
375 =item * INC completion driver - tab complete module names in use and require
377 =item * Interrupt plugin - traps SIGINT to kill long-running lines
379 =item * Keywords completion driver - tab complete Perl keywords and operators
381 =item * LexEnv plugin - variables declared with "my" persist between statements
383 =item * MultiLine::PPI plugin - continue reading lines until all blocks are closed
385 =item * Nopaste plugin - upload a session\'s input and output to a Pastebin
387 =item * PPI plugin - PPI dumping of Perl code
389 =item * Refresh plugin - automatically reload libraries with Module::Refresh
395 Matt S Trout - mst (at) shadowcatsystems.co.uk (L<http://www.shadowcatsystems.co.uk/>)
401 =item Stevan Little - stevan (at) iinteractive.com
403 =item Alexis Sukrieh - sukria+perl (at) sukria.net
407 =item mgrimes - mgrimes (at) cpan dot org
409 =item Shawn M Moore - sartak (at) gmail.com
411 =item Oliver Gorwits - oliver on irc.perl.org
413 =item Andrew Moore - C<< <amoore@cpan.org> >>
415 =item Norbert Buchmuller C<< <norbi@nix.hu> >>
417 =item Dave Houston C<< <dhouston@cpan.org> >>
421 =item Karen Etheridge C<< <ether@cpan.org> >>
427 This library is free software under the same terms as perl itself