This project has been utterly superseded by [pry](https://github.com/pry/pry), which has this as default functionality.  Use that.  

repl
====

a repl (Read Eval Print Loop) is an extremely powerful exploration and debugging tool.  I have often wished, while in the irb console, that I could evaluate some code in the context of some object.  This can be done with the irb method cb (change binding, I assume), like so:

bash-3.2$ irb
>> self
=> main
>> class Foo
>>   @@hidden = "I'm hidden"
>> end
=> "I'm hidden"
>> cb Foo
=> Foo
>> self
=> Foo
>> @@hidden
=> "I'm hidden"


The problem is that unless you remembered to stash the old self somewhere that would be visible from the place you cb'd to, you couldn't get back where you came from, and you'd have to restart irb.  Also, it feels very un-OO to be doing these global calls to cb.  This is just enough friction that I never used cb much.  However, with 24 lines of wrapping, both of these issues are resolved.

repl defines 2 modules, one for mixing into the target object, and another for doing the mixing.  Here's an example session:

bash-3.2$ irb
>> require "repl"
=> true
>> class Foo
>>   @@hidden = "I'm a hidden class variable"
>> end
=> "I'm a hidden class variable"
>> self
=> main
>> Foo.respond_to?("repl")
=> false
>> f = Foo.new
=> #<Foo:0x643e8>
>> f.respond_to?("repl")
=> false

Everything is normal up until this point.

>> HookRepl.replize_object(Foo, :class)
=> nil
>> f.respond_to?("repl")
=> false
>>  Foo.respond_to?("repl")
=> true
>> self
=> main

self is unchanged, but now Foo has been extended with a class method "repl".

>> Foo.repl
=> [main, Foo]
>> self
=> Foo
>> @@hidden
=> "I'm a hidden class variable"

As expected, we can now see inside the class, and poke about in it.

>> def bar
>>   "defined from repl"
>> end
=> nil

We can also define methods inside the class, somewhat more conveniently than with class_eval.

>> f
NameError: undefined local variable or method `f' for Foo:Class
        from (irb):20

note that f is not bound here.  Now let's get back into our old context.

>> stop_repl
=> main
>> f  # I'm not sure why f isn't bound here either.  Maybe I have a bug?  dunno.
NameError: undefined local variable or method `f' for main:Object
        from (irb):22
>> f = Foo.new
=> #<Foo:0x46dfc>
>> f.bar
=> "defined from repl"

and our changes are visible!  Now let's replize instances instead of classes.

>> class Bar
>> end
=> nil
>> HookRepl.replize_object(Bar, :object)
=> #<Class:0x37988>::Bar
>> Bar.respond_to?("repl")
=> false
>> Bar.new.respond_to?("repl")
=> true

By default, replize_object does both instances and classes.
>> HookRepl.replize_object(Object)
=> Object
>> Bar.respond_to?("repl")
=> true




COPYRIGHT
=========

Copyright (c) 2008 matt knox. See LICENSE for details.