From: Gavin Sinclair <gsinclair@...>
Date: 2002-11-26T09:32:44+09:00
Subject: Re: Things That Newcomers to Ruby Should Know (11/24/02)

From: "Daniel Carrera" <dcarrera@math.umd.edu>


>
> > And given that the concept of 'x++' is very rarely needed in a Ruby
program,
> > having iterators instead of for-loops, those extra three characters are
> > actually a very small percentage, amortised over the entire program.
>
> Regardless, is there a reason *not* to have '++'?
> It's the kind of shortcut that many programmers expect and I just can't
> think of any reason not to have it.  Following the principle of Least
> Surprise, I'd expect to find this feature, unless there is a good reason
> to avoid it.
>
> Daniel.

In other languages, ++/-- is a lot more than just 'x = x + 1'.  It's the
pre-/post- increment/decrement operator.  That is:

  int x[] = [5,6,7,8,9];
  int a = 1;
  x[++a];             // -> 7; a == 2
  x[a++];             // -> 7; a == 3
  x[a];               // -> 8; a == 3

Ruby can't/won't replicate this behaviour, so swiping the operators would
mislead.  I don't know what a[x += 1] does in Ruby, and I'm not going to ask.

Gavin