Forum: Ruby How to return an unmodifiable but nor frozen array?

Announcement (2017-05-07): is now read-only since I unfortunately do not have the time to support and maintain the forum any more. Please see and for other Rails- und Ruby-related community platforms.
LAMBEAU Bernard (Guest)
on 2009-01-08 16:00
(Received via mailing list)

Is there a mean to obtain an unmodifiable array which is not frozen?

Assume you're implementing a directed graph with adjacency lists. A
node would like to expose it's outgoing edges (to let users enjoy its
enumerability for example) but you would like to ensure that this
array will not be modified. A solution would be to duplicate it and I
know that efficiency should not be my concern, but ...

Markus S. (Guest)
on 2009-01-08 16:05
(Received via mailing list)
You can return the array in a container, this container redirects all
"read" operations to the array and does not redirect any "write"

class ArrayContainer
  def initialize(array)

  def [](idx)

  ... and so on

There is a specialized "delegate" class/module in ruby, using it should
result in better performance than the solution in my ArrayContainer


This topic is locked and can not be replied to.