Question

I am new to ruby but nonetheless I have installed various versions of Ruby using RVM,
Here’s the the output of my LOAD_PATH

ruby-1.9.2-p136 :001 > puts $LOAD_PATH
/home/jose/.rvm/rubies/ruby-1.9.2-p136/lib/ruby/site_ruby/1.9.1
/home/jose/.rvm/rubies/ruby-1.9.2-p136/lib/ruby/site_ruby/1.9.1/i686-linux
/home/jose/.rvm/rubies/ruby-1.9.2-p136/lib/ruby/site_ruby
/home/jose/.rvm/rubies/ruby-1.9.2-p136/lib/ruby/vendor_ruby/1.9.1
/home/jose/.rvm/rubies/ruby-1.9.2-p136/lib/ruby/vendor_ruby/1.9.1/i686-linux
/home/jose/.rvm/rubies/ruby-1.9.2-p136/lib/ruby/vendor_ruby
/home/jose/.rvm/rubies/ruby-1.9.2-p136/lib/ruby/1.9.1
/home/jose/.rvm/rubies/ruby-1.9.2-p136/lib/ruby/1.9.1/i686-linux

Ok. So the question here is, Where within these directories can I see the source code for classes like Array, or Time ? (I know, it’s an extremely n00b question, but I need to know.)

I’ve been needing to take a look at the source of Array for a long time.

Thanks in advance!

PS. Which class do you recommend looking at if I want to become a better ruby programmer?

Answer 1

The coolest gadget for code browsing I found so far is pry:
http://pry.github.com/

It’s an irb replacement with a lot of goodies. An example session so you can see how you can browse code with it (and you’ll also see that it can show the C-implementation of a class):

> pry
pry(main)> show-
show-command  show-doc      show-input    show-method   show-source
pry(main)> show-source Array

From: object.c in Ruby Core (C Method):
Number of lines: 6

static VALUE
rb_f_array(obj, arg)
    VALUE obj, arg;
{
    return rb_Array(arg);
}
pry(main)> cd Array
pry(Array):1> show-source each

From: array.c in Ruby Core (C Method):
Number of lines: 12

VALUE
rb_ary_each(ary)
    VALUE ary;
{
    long i;

    RETURN_ENUMERATOR(ary, 0, 0);
    for (i=0; i<RARRAY(ary)->len; i++) {
    rb_yield(RARRAY(ary)->ptr[i]);
    }
    return ary;
}
pry(Array):1>

Pry can of course also list the Ruby source of classes.

Another useful tool for browsing the C-source for Ruby is the Ruby code cross reference:
http://rxr.whitequark.org/

However right now it seems to be down, but hopefully it will be up again soon.