require 'enumerable/lazy'
pr = lambda{|e| e.tap{|e|p e.count}.tap{|e|p e.count}.tap{|e|e.rewind}.tap{|e|p e.count}}
# non-lazy
nl = File.open("/WINDOWS/system/setup.inf").lines; pr[nl]
#=> 1497
#=> 0
#=> 1497
# lazy
l = File.open("/WINDOWS/system/setup.inf").lines.lazy; pr[l]
#=> 1497
#=> 0
#=> 0
More than 5 years have passed since last update.
Register as a new user and use Qiita more conveniently
- You get articles that match your needs
- You can efficiently read back useful information
- You can use dark theme
List of users who liked
10