>From: Dave Thomas

>Reply-To: ruby-talk@ruby-lang.org

>To: ruby-talk@ruby-lang.org (ruby-talk ML)

>Subject: [ruby-talk:19076] Re: a+, a++, a+++, a++++, a+ ---, a + ***

>Date: Sat, 4 Aug 2001 00:17:05 +0900

>"Dat Nguyen" writes:

> > a = 0 # => 0

> >

> > a+ 1 # => 1

> >

> > a++ 1 # => 1

> >

> > a+++ 1 # => 1

> >

> > a+ ++++++ 1 # => 1

> >

> > a + --- 3 #=>

> >

> > a + *** 3 #=> SyntaxError: compile error

> > (irb):28: parse error

> >

> > Why?

>Because '+' is both a unary and a binary operator, and '*' isn't.

>Now, for extra credit, why is this OK

> a+ 1

a.+(1)

>and this isn't:

> a +1

sending to the root object the message "a +1" does not fail if the following was defined:

def a(b)

end

but the next question raised. I cannot override the above with:

def a(b, c)

end

and expect:

a +1

a 2 3

to work. The list of args is different. Why doesn't it work?

Regards

Dat

>Regards

>Dave