From: "David A. Black" <dblack@...>
Date: 2004-09-17T07:06:31+09:00
Subject: Re: Ex-Perl coders: Howz it feel to convert to Ruby?

Hi --

On Fri, 17 Sep 2004, Brian Wisti wrote:

> 
> --- Nate Smith <nsmith5@nist.gov> wrote:
> 
> > Try
> > 
> > print "a" + 1
> > 
> > Won't work -- you have to do
> > 
> > print "a" + 1.to_s
> > 
> > 
> > Nate
> 
> That "+" means you're building a new string from two Strings. Since the
> second operand is not a String, the conversion has to be explicit.

If the second operand responds to to_str, then its response to to_str
will be used in cases where only a string will do:

  irb(main):016:0> obj = Object.new
  => #<Object:0x402a6e94>
  irb(main):017:0> puts "this is an " + obj
  TypeError: cannot convert Object into String
          from (irb):17:in `+'
          from (irb):17
          from :0
  irb(main):018:0> def obj.to_str; "implicit string representation!";
  end
  => nil
  irb(main):019:0> puts "this is an " + obj
  this is an implicit string representation!


David

-- 
David A. Black
dblack@wobblini.net