From: Daniel Berger <djberg96@...>
Date: 2005-05-23T11:25:21+09:00
Subject: Re: join not in Enumerable

Ara.T.Howard wrote:
>
> > Also, every class except Array would have to have a custom
definition of
> > join, since there's no reasonable default behavior for any class
outside of
> > Array.
>
> really?
>
>    set = Set::new
>    set.join ','
>
>    ll = LinkedList::new
>    ll.join '->'
>
>    dll = DoublyLinkedList::new
>    dll.join '<->'
>
>    v = BitVector::new
>    v.join '|'
>
>    path = graph.shortest_path from, to
>    path.join '=>'
>
>    string = String::new
>    string.join "<br>"
>
>    stack = Stack::new
>    stack.join '-'
>
>    rope = Rope::new
>    rope.join '_'
>
>    priority_queue = PriorityQueue::new
>    priority_queue.join(','){|priority_and_obj| priority_and_obj.join
':'}
>
> come to mind ;-)

Fine, replace "Array" with "most lists" and my point still stands.

> > And if every class would have to implement its own version of a
method, that
> > method doesn't belong in a module.  Modules are not interfaces.
>
> why would every class have to implement it's own?  with the defintion
we've
> been throwing around we already have things like
>
>    harp:~/build/ruby > ./ruby -e'html = "line1\nline2\nline3".join
"<br>"; p html'
>    "line1\n<br>line2\n<br>line3"
>
> which is kinda handy and makes good sense no?

No, it doesn't make sense.

Regards,

Dan