From: "Hal E. Fulton" <hal9000@...>
Date: 2003-03-27T08:02:20+09:00
Subject: Re: syntax

----- Original Message ----- 
From: <rodrigo.bermejo@ps.ge.com>
To: "ruby-talk ML" <ruby-talk@ruby-lang.org>
Sent: Wednesday, March 26, 2003 4:15 PM
Subject: Re: syntax


> irb(main):006:0> class Fixnum
> irb(main):007:1> def inc(val=1)
> irb(main):008:2>  self += val
> irb(main):009:2> end
> irb(main):010:1> end
> SyntaxError: compile error
> (irb):8: Can't change the value of self
>  self += val
>         ^
>     from (irb):10
> irb(main):011:0> ^C
> (%:~)- ruby -v
> ruby 1.6.7 (2002-03-19) [i386-linux]
> 
> 
> 
> 
> Robert wrote:
> 
> >class Fixnum
> >  def inc(val=1)
> >    self += val
> >  end
> >end
> >
> >1.inc
> >
> >:-)
> >

Rodrigo,

I think Robert was being facetious.

This can't work for a variety of reasons.

Robert's point (I think) was: What do you
get if you increment a constant? It's surely
wrong to change all values of 1 to something
else.

For example, if you actually *could* transform
the object 1 into the object 2, then this code
fragment

  x = 1
  y = 1.inc
  puts x

would print 2 rather than 1.

The lack of a ++ operator (and the rationale
behind it) has been discussed many times over
the last three years or so.

If it's not in the FAQ at 
http://www.rubygarden.org/iowa/faqtotum --
well, it should be. :)

And you can also search the list archives at
www.ruby-talk.org (search for ++ or increment).

Cheers,
Hal