From: Guillaume Cottenceau <gc@...>
Date: 2001-08-24T04:46:32+09:00
Subject: [ruby-talk:20203] Re: ++ Operator

Hi !

matz@ruby-lang.org (Yukihiro Matsumoto) writes:

> Hi,
> 
> In message "[ruby-talk:20191] Re: ++ Operator"
>     on 01/08/24, Guillaume Cottenceau <gc@mandrakesoft.com> writes:
> 
> |Yet, from the "parsing" point of view (excuse the potential improper use
> |of this term), if `counter += 1' is effectively shorthand for `counter =
> |counter + 1', why `counter ++' could not be shortand for `counter += 1'?
> |
> |If this is done early enough in the code, I think this should be possible?
> 
> It's possible.  But do you think this is what you really want?
> Think about "a++", where a = "foo" for example.  I think it's
> confusing, rather than useful.

Maybe I just don't see the future problems, but I think it would not be
very confusing. It would try to "increment" the object behind the
variable. It would fail just as it currently fails, on a String:

irb(main):001:0> a = "foo"
"foo"
irb(main):002:0> a += 1
TypeError: failed to convert Fixnum into String
        from (irb):2:in `+'
        from (irb):2
irb(main):003:0>


The ++ would also fail.... unless you would imagine it should succeed for
some reason ? If the "++" is just converted to "+= 1" ok it would fail for
the same reason, but I imagine you would like that the "++" behaves
differently among objects because some of them could be "incremented"
while not "added the Fixnum `1'".

In my opinion, I would not be shocked if it would simply convert to +=1
and then fail for relevant reason for most objects.

The only moment where I miss the "++" is actually when I need to increment
a Number... Writing "a += 1" is just.. depressing.. ;p.





-- 
Guillaume Cottenceau - http://people.mandrakesoft.com/~gc/