From: Johan Holmberg <holmberg@...>
Date: 2004-01-16T00:03:39+09:00
Subject: Re: Concatenating variable number of Arrays ?


On Thu, 15 Jan 2004, Robert Klemme wrote:
> "Florian Frank" <flori@ping.de> schrieb im Newsbeitrag
[...]
> > If you extend Symbol like this:
> >
> > class Symbol
> >   def to_proc
> >     lambda { |a, b| a.__send__(self, b) }
> >   end
> > end
> >
> > You could also write
> >
> > arr2 = arr1.inject([], &:+)
> >
> > That's pretty similar to how it is done in most functional programming
> > languages.
>
> Amazing!  Only that it's less efficient since your approach creates more
> temporary arrays.
>

I agree.
Where can I read about 'to_proc' and how it works ?

To avoid "+" I tried to changing to "concat" and this seems to work too:

    class Symbol
	def to_proc
	    lambda { |acc, x| acc.__send__(self, x) }
	end
    end

    arr1 = [ [1,2,3], [4,5,6], [7,[8,9]] ]
    arr2 = arr1.inject([], &:concat)

/Johan Holmberg