I really like Ruby. Working with it is just so much fun! I wrote my checkbook balancer in it, and everything else I do is pretty much just messing around because it's fun. I need to find something more practical to do, but it's usually easier for me to use Perl instead.
Today, I wondered how easy it would be to iterate over an array in n-sized chunks at a time. This came to mind because I want to iterate over pairs in a list in Rubric's code. (I wish I'd written it in Ruby, sort of.)
So, I ended up writing a few methods for Array. It wasn't hard, but I rewrote them a number of times, each time feeling like I was getting a better grip on the Ruby Way.
class Array def each_n(n, &block) (0 .. (self.size/n.to_f).ceil - 1).map { |i| block.call(self[i*n,n]) } end def collect_n(n, &block) c = [] self.each_n(n) { |nth| block.call(nth).each { |x| c << x } } return c end def collect_n!(n, &block) self[0, self.size] = self.collect_n(n, &block) end alias_method :map_n, :collect_n alias_method :map_n!, :collect_n! end digits = [ 1,2,3,4,5,6,7,8,9 ]
puts "digits counted in fives:" digits.each_n(5) { |x| puts x, "---" }
puts "digits, multipled in threes by [0,1,2], counted in fives:" digits.collect_n!(3) { |nth| i = -1; nth.map { |x| x * i+=1; } } digits.each_n(5) { |x| puts x, "---" }