multi-select 2 recursive

multi-select2.rb

def multi_split2(str, delims)
  multi(str, delims, [])
end

def multi(str, delims, sum)
  return sum if str.empty?
  temp, token = "", ""

  while !is_token_prefix? str[0], delims 
    token << str[0]
    str.slice!(0) 
    break if str.empty?
  end 

  sum << token
  
  while is_token_prefix? str[0], delims
    temp << str[0]
    str.slice!(0)
    break if is_token?(temp, delims)
    if is_token?(temp + str[0], delims)
      str.slice!(0)
      break
    end
  end 

  multi(str, delims, sum)
end

def is_token_prefix?(prefix, tokens)
  tokens.each { |token| return true if token.start_with?(prefix) }
  false
end

def is_token?(str, tokens)
  tokens.each { |token| return true if token == str }
  false
end


puts multi_split2("dogxycat", ["og", "y"]).to_s
puts multi_split2('ddxy', ['d']).to_s
puts multi_split2("dogxycat", ["og", "y"]).to_s
puts multi_split2("dogxycat", ["og", "dog"]).to_s