a functional altermative

kata.rb

# generate 100 random integers and store them in a file

STORE = "numbers.txt"

unless File.exists?(STORE)
  File.write(STORE, 100.times.map { Random.rand(10) }.join("\n"))
end

numbers = File.read(STORE).split("\n").map { |n| n.to_i }

puts numbers

# numbers.each_with_index do |num, index|
#   puts "#{index}: #{"#" * num}"
# end

# 91: ######
# 92: ######
# 91-92: ######

# keep track of a previous number
# if current number is same as previous number, do nothing
# otherwise, print summary of previous group

# previous_num = nil
# previous_index = nil

# numbers.each_with_index do |num, index|
#   if previous_num
#     next if num == previous_num
#     if previous_index == index - 1
#       puts "#{previous_index}: #{"#" * previous_num}"
#     else
#       puts "#{previous_index}-#{index-1}: #{"#" * previous_num}"
#     end
#   end

#   previous_num = num
#   previous_index = index
# end

# total = numbers.length
# if previous_index == total - 1
#   puts "#{previous_index}: #{"#" * previous_num}"
# else
#   puts "#{previous_index}-#{total-1}: #{"#" * previous_num}"
# end

# initial = {
#   last_num: nil,
#   result: []
# }

# grouped = numbers.each_with_index.each_with_object(initial) do |pair, state|
#   num, _ = pair
#   if state[:last_num] == num
#     state[:result].last.push(pair)
#   else
#     state[:result].push([pair])
#   end
#   state[:last_num] = num
# end[:result]

# grouped.each do |group|
#   if group.length == 1
#     num, index = group.last
#     puts "#{index}: #{"#" * num}"
#   else
#     num, first_idx = group.first
#     _, last_idx = group.last
#     puts "#{first_idx}-#{last_idx}: #{"#" * num}"
#   end
# end

numbers.each_with_index.slice_when do |prev, curr|
  prev.first != curr.first
end.each do |group|
  case group
  in [[num, index]]
    puts "#{index}: #{"#" * num}"
  in [[num, first_idx], *, [_, last_idx]]
    puts "#{first_idx}-#{last_idx}: #{"#" * num}"
  end
end