From: Robert Klemme <shortcutter@...>
Date: 2007-09-16T20:30:04+09:00
Subject: Re: one line to print the statement AS WELL AS the evaluated value like in C

On 15.09.2007 19:13, John Joyce wrote:
> 
> On Sep 15, 2007, at 1:51 AM, kendear wrote:
> 
>> i wonder in Ruby, is there a line method to do something like in C
>>
>>
>> print_val("Array[3] + 1")
>>
>> and get the printout of
>>
>>
>> Array[3] + 1  is   3.345

def print_val(expr,b=binding)
   print( expr, " is ", eval(expr,b).inspect, "\n")
end

irb(main):026:0> a=%{foo bar baz}
=> "foo bar baz"
irb(main):027:0> print_val "a[1]", binding
a[1] is 111
=> nil
irb(main):028:0> print_val "a[1]"
NameError: undefined local variable or method `a' for main:Object
         from (irb):21:in `print_val'
         from (irb):21:in `print_val'
         from (irb):28
         from :0

You can even omit the "b" argument if you use something like 
"Binding.of_caller".

Kind regards

	robert