From: yermej <yermej@...>
Date: 2007-11-26T13:45:03+09:00
Subject: Re: Printing variable name and value

On Nov 25, 9:54 pm, Adam Bender <aben...@gmail.com> wrote:
> Note:  parts of this message were removed by the gateway to make it a legal Usenet post.
>
> Hi, I want a function that will pretty-print the name and value of a
> variable, so I can avoid writing things like:
> puts "x is #{x}"
>
> Ideally, I would just be able to pass the variable, or at most a label, to a
> function, and have it do this for me.  I wrote something that almost works;
> I have to pass the current binding as well.  Is there a way to avoid this?
> Is there a better way to do what I've done below?  Thanks,
>
> Adam
>
> ===============================
>
> #!/usr/bin/ruby
>
> def pprint(label, bind)
>   typ = eval(label.to_s, bind).class.name
>   case typ
>   when "Array"
>     arr = eval(label.to_s, bind)
>     puts label.to_s + " is [" + arr.join(", ") + "]"
>
>   when "Hash"
>     hash = eval(label.to_s, bind)
>     puts label.to_s + " is {" +
>       hash.collect { |k, v| "#{k} => #{v}" }.join(", ") + "}"
>
>   when "Fixnum"
>     puts label.to_s + " is " + eval(label.to_s, bind).to_s
>
>   when "String"
>     puts label.to_s + " is " + eval(label.to_s, bind)
>
>   else
>     puts "unknown type: #{typ}"
>   end
> end
>
> a = 3
> pprint :a, binding
>
> y = "aasdf"
> pprint :y, binding
>
> x = [1, 2, 3]
> pprint :x, binding
>
> z = {'a' => 1, 'b' => 3}
> pprint :z, binding

Check the group archives as this was discussed recently. The example
you gave could be written as:

def pprint(label, bind)
  puts "#{label} is #{eval(label.to_s, bind).inspect}"
end

Jeremy