From: Run Paint Run Run <redmine@...>
Date: 2009-08-05T00:43:27+09:00
Subject: [ruby-core:24745] [Bug #1880] Hash#flatten Doesn't Operate Recursively for Hash Values

Bug #1880: Hash#flatten Doesn't Operate Recursively for Hash Values
http://redmine.ruby-lang.org/issues/show/1880

Author: Run Paint Run Run
Status: Open, Priority: Low
Category: core
ruby -v: ruby 1.9.2dev (2009-08-04 trunk 24388) [i686-linux]

Hash#flatten claims to flatten recursively if given an argument specifying the depth. This works as expected for Array values, but has no bearing on Hash values. 

  >> h = {orange: :orange, coconut: {inside: :white, outside: :brown}, grapes: {colour: [:red, :green]}}
  >> h.flatten
  => [:orange, :orange, :coconut, {:inside=>:white, :outside=>:brown}, :grapes, {:colour=>[:red, :green]}]
  >> h.flatten(20)
  => [:orange, :orange, :coconut, {:inside=>:white, :outside=>:brown}, :grapes, {:colour=>[:red, :green]}]

This seems peculiar. If the user has specified a depth he's explicitly stating the level of recursion to flatten; not how he wants Array values to be treated. IOW, I expected #flatten(depth) to call #flatten on Hash values as appropriate. This can be generalised to: call #flatten on values until the depth has been reached.


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