runlength encode/decode binary strings

rle.rb

s = "1100100001100001110111101110110011111010010000100101011110010110"

def rle(s)
  s.gsub(/(0{3,9}|1{3,9})/) { "#{$1.size}#{$1.chars.first}" }
end

def rld(s)
  s.gsub(/([3-9])([01])/) { $2 * $1.to_i } 
end

p s
p rle(s)
p rld(rle(s))

p [:works, s == rld(rle(s))]