Thanks Rob, in line 6 (where #!/usr/bin/ruby -w is line 1) where results[-1]<<element, is there a check to verify that the element's cue is true and henceforth start a new and empty array?
On Aug 6, 6:32 pm, Rob Biedenharn <[email protected]> wrote: > On Aug 6, 2009, at 3:22 PM, Nik wrote: > > > > > > > Hello, I have this big array of hashes: > > A =[ h0, h1, h2, ..., hn] > > some hi's' :cue key is true, others' is false. > > e.g., > > h1[:cue] = false > > h2[:cue] = false > > h3[:cue] = true > > h4[:cue] = false > > h5[:cue] = true > > ... > > hn[:cue] = ... > > > Again, these hashes are in an array, A. > > > Now, I'd like to group them into smaller arrays whose last item has a > > true cue > > so > > A' = [ [h1, h2, h3], [h4, h5], ... , [...] ] > > > Is there a built-in method to cook this up? > > If not, what combination of methods might you think would work most > > efficiently? > > > Thank You > > Well, this seems to be a tasty dish. I took some liberty with your > minimal spec, but you should see the first test for the usage that > maps to your example. > > #!/usr/bin/ruby -w > class Array > def split_when > result = [[]] > each do |element| > result[-1] << element > if block_given? ? yield(element) : element > result << [] > end > end > result.pop if result.last.empty? > result > end > end > > if File.expand_path($0) == File.expand_path(__FILE__) > require 'test/unit' > class SplitWhenTest < Test::Unit::TestCase > def setup > h1 = { :cue => false } > h2 = { :cue => false } > h3 = { :cue => true } > h4 = { :cue => false } > h5 = { :cue => true } > �...@ary = [ h1, h2, h3, h4, h5 ] > �...@expected = [ [h1, h2, h3], [h4, h5] ] > end > > def test_example_from_email > assert_equal @expected, @ary.split_when {|e| e[:cue]} > end > > def test_simple > original = [ false, true, false, false, true, true, false, > true, false, true, false ] > expected = [[false, true],[false, false, true],[true],[false, > true],[false, true],[false]] > assert_equal expected, original.split_when, "no block" > assert_equal expected, original.split_when {|e|e}, "simple block" > end > end > end > __END__ > > :code/ruby $ ./array_split_when.rb > Loaded suite ./array_split_when > Started > .. > Finished in 0.000585 seconds. > > 2 tests, 3 assertions, 0 failures, 0 errors > > -Rob > > Rob Biedenharn http://agileconsultingllc.com > [email protected] --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
