From: Robert Klemme <bob.news@...>
Date: 2004-01-15T23:31:41+09:00
Subject: Re: Concatenating variable number of Arrays ?


"Florian Frank" <flori@ping.de> schrieb im Newsbeitrag
news:1074168191.4130.26.camel@lambda.eavesdrop.ping.de...
> On Wed, 2004-01-14 at 16:33, Johan Holmberg wrote:
> > The best way I have found until now, of doing what I want is
> >
> >     arr2 = arr1.inject([]) {|acc,x| acc.concat x}
>
> You can also use "+" here:
>
> arr2 = arr1.inject([]) { |a,x| a + x }
>
> > But I feel that the thing I want to do (concatenating a variable
> > number arrays) is such a natural thing, that it deserves a cleaner
> > way of being expressed.
>
> 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.

Regards

    robert