DDC Plugin
[p5sagit/Devel-REPL.git] / README
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6aa58492 1NAME
2 Devel::REPL - a modern perl interactive shell
3
4SYNOPSIS
5 my $repl = Devel::REPL->new;
6 $repl->load_plugin($_) for qw(History LexEnv);
7 $repl->run
8
9 Alternatively, use the 're.pl' script installed with the distribution
10
11 system$ re.pl
12
13DESCRIPTION
14 This is an interactive shell for Perl, commonly known as a REPL - Read,
15 Evaluate, Print, Loop. The shell provides for rapid development or
16 testing of code without the need to create a temporary source code file.
17
18 Through a plugin system, many features are available on demand. You can
19 also tailor the environment through the use of profiles and run control
20 files, for example to pre-load certain Perl modules when working on a
21 particular project.
22
23USAGE
24 To start a shell, follow one of the examples in the "SYNOPSIS" above.
25
26 Once running, the shell accepts and will attempt to execute any code
27 given. If the code executes successfully you'll be shown the result,
28 otherwise an error message will be returned. Here are a few examples:
29
30 $_ print "Hello, world!\n"
31 Hello, world!
32 1
33 $_ nosuchfunction
34 Compile error: Bareword "nosuchfunction" not allowed while "strict subs" in use at (eval 130) line 5.
35
36 $_
37
38 In the first example above you see the output of the command ("Hello,
39 world!"), if any, and then the return value of the statement (1).
40 Following that example, an error is returned when the execution of some
41 code fails.
42
43 Note that the lack of semicolon on the end is not a mistake - the code
44 is run inside a Block structure (to protect the REPL in case the code
45 blows up), which means a single statement doesn't require the semicolon.
46 You can add one if you like, though.
47
48 If you followed the first example in the "SYNOPSIS" above, you'll have
49 the History and LexEnv plugins loaded (and there are many more
50 available). Although the shell might support "up-arrow" history, the
51 History plugin adds "bang" history to that so you can re-execute chosen
52 commands (with e.g. "!53"). The LexEnv plugin ensures that lexical
53 variables declared with the "my" keyword will automatically persist
54 between statements executed in the REPL shell.
55
56 When you "use" any Perl module, the "import()" will work as expected -
57 the exported functions from that module are available for immediate use:
58
59 $_ carp "I'm dieeeing!\n"
60 String found where operator expected at (eval 129) line 5, near "carp "I'm dieeeing!\n""
61 (Do you need to predeclare carp?)
62 Compile error: syntax error at (eval 129) line 5, near "carp "I'm dieeeing!\n""
63 BEGIN not safe after errors--compilation aborted at (eval 129) line 5.
64
65 $_ use Carp
66
67 $_ carp "I'm dieeeing!\n"
68 I'm dieeeing!
69 at /usr/share/perl5/Lexical/Persistence.pm line 327
70 1
71 $_
72
73 To quit from the shell, hit "control+d" or "control+c".
74
75 Run Control Files
76 For particular projects you might well end up running the same commands
77 each time the REPL shell starts up - loading Perl modules, setting
78 configuration, and so on. A run control file lets you have this done
79 automatically, and you can have multiple files for different projects.
80
81 By default the "re.pl" program looks for "$HOME/.re.pl/repl.rc", and
82 runs whatever code is in there as if you had entered it at the REPL
83 shell yourself.
84
85 To set a new run control file that's also in that directory, pass it as
86 a filename like so:
87
88 system$ re.pl --rcfile myproject.pc
89
90 If the filename happens to contain a forwardslash, then it's used
91 absolutely, or realive to the current working directory:
92
93 system$ re.pl --rcfile /path/to/my/project/repl.rc
94
95 Within the run control file you might want to load plugins. This is
96 covered in "The REPL shell object" section, below.
97
98 Profiles
99 To allow for the sharing of run control files, you can fashion them into
100 a Perl module for distribution (perhaps via the CPAN). For more
101 information on this feature, please see the Devel::REPL::Profile manual
102 page.
103
104 A default profile ships with "Devel::REPL"; it loads the following
105 plugins:
106
107 * Devel::REPL::Plugin::History
108
109 * Devel::REPL::Plugin::LexEnv
110
111 * Devel::REPL::Plugin::DDS
112
113 * Devel::REPL::Plugin::Packages
114
115 * Devel::REPL::Plugin::Commands
116
117 * Devel::REPL::Plugin::MultiLine::PPI
118
119 Plugins
120 Plugins are a way to add funcionality to the REPL shell, and take
121 advantage of "Devel::REPL" being based on the Moose object system for
122 Perl 5. This means it's simple to 'hook into' many steps of the R-E-P-L
123 process. Plugins can change the way commands are interpreted, or the way
124 their results are output, or even add commands to the shell environment.
125
126 A number of plugins ship with "Devel::REPL", and more are available on
127 the CPAN. Some of the shipped plugins are loaded in the default profile,
128 mentioned above.
129
130 Writing your own plugins is not difficult, and is discussed in the
131 Devel::REPL::Plugin manual page, along with links to the manual pages of
132 all the plugins shipped with "Devel::REPL".
133
134 The REPL shell object
135 From time to time you'll want to interact with or manipulate the
136 "Devel::REPL" shell object itself; that is, the instance of the shell
137 you're currently running.
138
139 The object is always available through the $_REPL variable. One common
140 requirement is to load an additional plugin, after your profile and run
141 control files have already been executed:
142
143 $_ $_REPL->load_plugin('Timing');
144 1
145 $_ print "Hello again, world!\n"
146 Hello again, world!
147 Took 0.00148296356201172 seconds.
148 1
149 $_
150
151REQUIREMENTS
152 In addition to the contents of the standard Perl distribution, you will
153 need the following:
154
155 * Moose >= 0.64
156
157 * MooseX::Object::Pluggable >= 0.0009
158
159 * MooseX::Getopt >= 0.15
160
161 * MooseX::AttributeHelpers >= 0.14
162
163 * namespace::clean
164
165 * File::HomeDir
166
ab213f1f 167 * Task::Weaken
6aa58492 168
ab213f1f 169 Optionally, some plugins if installed will require the following
170 modules:
6aa58492 171
172 * PPI
173
ab213f1f 174 * Data::Dump::Streamer
175
176 * File::Next
177
6aa58492 178 * B::Keywords
179
ab213f1f 180 * Lexical::Persistence
6aa58492 181
182 * App::Nopaste
183
ab213f1f 184 * Module::Refresh
185
6aa58492 186AUTHOR
187 Matt S Trout - mst (at) shadowcatsystems.co.uk
188 (<http://www.shadowcatsystems.co.uk/>)
189
190CONTRIBUTORS
191 Stevan Little - stevan (at) iinteractive.com
192 Alexis Sukrieh - sukria+perl (at) sukria.net
193 epitaph
194 mgrimes - mgrimes (at) cpan dot org
195 Shawn M Moore - sartak (at) gmail.com
ab213f1f 196 Oliver Gorwits - oliver on irc.perl.org
6aa58492 197
198LICENSE
199 This library is free software under the same terms as perl itself
200