From: Marko Schulz <in6x059@...>
Date: 2002-04-26T08:37:17+09:00
Subject: Re: Numberic#prev

On Thu, Apr 25, 2002 at 04:37:23AM +0900, Stefan Schmiedl wrote:
> 
> Well, then we have two possibilities:
> a) there is no String#prev
> b) there is a STring#prev with a preference.

I strongly favor a): 
- String#succ is a convenience method. It is nice to have, but one
  should not conclude the necessity to have the reverse.
- String#pred is not really necessary. Even a lot less than
  String#succ.
- String#pred would require a lot of questionable distinction of
  cases. A lot more than String#succ. (The predecessor of "foo"
  might be "bar", "baz" or "zoo". What do we go for? Hacker 1: "bar"
  of course. Hacker 2: No "baz" is more reasonable. Hacker 3: "zoo" is
  what most people will expect.)

> Tell me, folks: How do you feel about the square root?

I think it is a bad example: Every positive, real number has exactly
two real square roots. If I have one of the two, I can easily get the
other one by negation. It is common to mention or return only the
positive square root because of this.

-- 
marko schulz