RosettaCodeData/Task/First-class-environments/Ruby/first-class-environments-2.rb

37 lines
817 B
Ruby

# Build environments
envs = (1..12).map do |n|
e = class Object
# This is a new lexical scope with no local variables.
# Create a new binding here.
binding
end
eval(<<-EOS, e).call(n)
n, cnt = nil, 0
proc {|arg| n = arg}
EOS
e
end
# Until all values are 1:
until envs.all? {|e| eval('n == 1', e)}
envs.each do |e|
eval(<<-EOS, e) # Use environment _e_
printf "%4s", n
if n > 1
cnt += 1 # Increment step count
n = if n.odd? # Calculate next hailstone value
n * 3 + 1
else
n / 2
end
end
EOS
end
puts
end
puts '=' * 48
envs.each do |e| # For each environment _e_
eval('printf "%4s", cnt', e) # print the step count
end
puts