From: Dave Thomas <Dave@...>
Date: 2001-09-24T06:21:58+09:00
Subject: [ruby-talk:21611] Re: Please translate this easy snip of C++ to Ruby

"Mikkel Damsgaard" <mikkel_damsgaard@mailme.dk> writes:

> > Ogle this awesome snip of C++:
> > 
> >         #define TRACE_(x) cout << #x ": " << x << endl

>....

> The closest I come is this:
> 
> def trace(expr)
>   print expr + "=", eval(expr,TOPLEVEL_BINDING)
>   puts
> end

I quite like:

     def trace(&b)
       f = yield
       puts "#{f}: #{eval(f, b).inspect}"
     end

     a = 1
     f = 2
     trace {"a+f"}


It works in any binding, not just the top level one.


Regards


Dave