From: Piergiuliano Bossi <p_bossi_AGAINST_SPAM@...>
Date: 2004-02-10T03:49:57+09:00
Subject: evaluate and print an expression

I hope that what I'm asking doesn't sound too weird, but I'm trying to 
understand if in ruby is possible to print and evaluate an expression at 
the same time. I know for example that I can do like this:

irb(main):001:0> expr = "1+2==3"
=> "1+2==3"
irb(main):002:0> puts expr + ' ==> ' + (eval expr).to_s
1+2==3 ==> true
=> nil

What I don't like is to specify the expression as a string. I'd rather 
prefer to manage code directly, but I don't know exactly how to print it 
and evaluate it at the same time. Ideally, I'd like to change the 
following code in order to print block body:

irb(main):012:0> def evaluate(&code)
irb(main):013:1>   p code
irb(main):014:1>   code.call
irb(main):015:1> end
=> nil
irb(main):016:0> evaluate { 1+2==3 }
#<Proc:0x02a4ea78@(irb):16>
=> true

Do you see what I mean? Instead of having:
	#<Proc:0x02a4ea78@(irb):16>
I'd like to get:
	{ 1+2==3 }
or something like that.

I know that in lisp this can be easily done due to its nature (that is, 
code is data and data is code), but in ruby?

Thanks for your help!
Ciao, Giuliano

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