Split a ruby string into X roughly even length lines, but don't break words.

str_in_lines.rb

def str_in_lines(str, x)
  word_break_indices = []
  str.to_enum(:scan,/\b/).map do |m,|
    word_break_indices << $`.size
  end
  
  perfect_split_indices = (0..str.length).step(str.length/x).to_a
  actual_split_indices = perfect_split_indices.map{ |si| word_break_indices.min_by{ |wbi| (wbi - si).abs } }
  actual_split_indices.push(str.length) unless actual_split_indices.last == str.length
  
  actual_split_indices.each_cons(2).map do |si, ei|
    str[si..ei-1]
  end
end