From: Martin DeMello <martindemello@...>
Date: 2006-12-07T03:12:23+09:00
Subject: Re: join_with

On 12/6/06, Logan Capaldo <logancapaldo@gmail.com> wrote:
> >
> > hex_ip.scan(/../).join_with('.') {|i| i.hex}
>   hex_ip.scan(/../).map {|i| i.hex}.join('.')
> Hey look, the long way is even shorter! Do you just want to conflate

I knew someone would say that :)

> these two because theres room in the interface? That seems like a silly
> reason. It would also set a bad precendent. (Well hey, delete doesn't
> take a block, lets add one and pass the deleted item in...)

No, more because map-then-join is a very common pattern, and the
complementary argument lists let us combine them neatly.

html_table = ary.jmap("\n") {|col|
  col.jmap {|cell| "<td>#{cell}</td>"}
}

as opposed to

html_table = ary.map {|col|
  col.jmap {|cell| "<td>#{cell}</td>"}.join
}.join("\n")

The benefit is that the block is the last argument to what is
conceptually a single operation.

martin