From: sabbyxtabby@... (Sabby and Tabby)
Date: 2004-03-14T20:29:35+09:00
Subject: Re: Extended information about a method's caller

"Robert Klemme" <bob.news@gmx.net> wrote:

> "Bill Atkins" <batkins57@myway.com> schrieb im Newsbeitrag
> news:20040312040924.AB9DF3977@mprdmxin.myway.com...
> >
> > Is there any way to get a list of the arguments passed to a method's
> caller?  I am aware of Kernel.caller, but it seems like it just gives a
> method name.
> 
> If you know the argument names you might be able to hack something together
> with set_trace_func.  But why don't you just pass them on? :-)

Or, if you hacked something together with set_trace_func, you might[1]
be able to know the argument names. :)

  module Kernel
    set_trace_func proc {|*a|
      $bind = a[4] unless a[3] == :argument_values
    }
  
    def argument_values
      eval <<-'CODE', $bind
        caller(0)[0] =~ /`(.*)'/ or return
        $arity = method($1).arity
        $args = local_variables[0, $arity.abs]
        $args[-1] = '*' + $args[-1] if $arity < 0
        eval "[#{$args * ','}]"
      CODE
    end
  end
  
  class Test
    def test(x, *y)
      i = 0
      z = 0..9
      p argument_values
    end
  end

  Test.new.test(4, 5, 6)

[1] The ordering of local variables returned by local_variables
    may be accidental.