From: Daniel Berger <djberge@...>
Date: 2003-07-16T03:56:48+09:00
Subject: Re: += vs << when appending arrays to an array

Doug Beaver wrote:
> 
> hello,
> 
> i'm looking for a nice idiomatic way to append to an array.  i'm porting
> some encryption code from C to ruby, i don't have the code in front of
> me but a relevant example is below:
> 
> def translate(str="")
>   ret = []
>   str.each_byte { |byte| ret << byte }
>   ret
> end

First, use unpack().  It's faster.

def translate(str="")
   str.unpack("C*")
end

> 
> bytes = []
> bytes << translate("foo")
> bytes += translate("foo")
> 
> p bytes
> 
> i'm using ruby 1.6.8, btw...

I couldn't get it to work with << the way that you describe.  You have a
couple of options.  First, use the splat operator with push(): e.g.

push(*translate("foo")).

Another option is to just call bytes.flatten! when you're done storing
stuff within the bytes array.

I think the only way to get this to work would be to convince Matz that
<<
should accept multiple arguments, the same as push().  Then you could
do:

bytes << *translate("foo")

Regards,

Dan