lazy_enumerator.rb

#!/usr/bin/ruby

# https://bugzilla.suse.com/show_bug.cgi?id=1132650
# https://github.com/yast/yast-packager/pull/434

def file_properties(filename)
  print "."
  File.lstat(filename)
end

def interesting?(stat)
  print "?"
  stat.symlink?
end

filenames = Dir.glob("/usr/lib/*")

all_props = filenames.map { |fn| file_properties(fn) }
int_props = all_props.find_all { |p| interesting?(p) }.to_a

puts "NORMAL"
puts int_props.size

all_props_lazy = filenames.lazy.map { |fn| file_properties(fn) }
int_props_lazy = all_props_lazy.find_all { |p| interesting?(p) }.to_a

puts "LAZY"
puts int_props_lazy.size