From: "mame (Yusuke Endoh)" Date: 2012-11-20T21:09:26+09:00 Subject: [ruby-core:49685] [ruby-trunk - Feature #6376] Feature lookup and checking if feature is loaded Issue #6376 has been updated by mame (Yusuke Endoh). Assignee changed from mame (Yusuke Endoh) to matz (Yukihiro Matsumoto) Yes I know what you want. But I don't know why you want it. In general, I don't think that it is a good idea to depend on whether a feature is loaded or not. Rather, you should make sure to require what feature you need. So, please elaborate your use case. I guessed one use case: you want to use one of many alternative libraries, for example, either eventmachine or Celluloid::IO. In such a case, you may want to try to require one, and if a LoadError is raised, then require the other. -- Yusuke Endoh ---------------------------------------- Feature #6376: Feature lookup and checking if feature is loaded https://bugs.ruby-lang.org/issues/6376#change-33206 Author: trans (Thomas Sawyer) Status: Assigned Priority: Normal Assignee: matz (Yukihiro Matsumoto) Category: core Target version: next minor $LOADED_FEATURES is useful to know what "files" have been loaded. But it doesn't really tell us what "features" have been loaded. If there where were a way to look-up a load path, without actually loading it then it would be possible to compare that to $LOADED_FEATURES and thus know. e.g. require 'ostruct' $LOADED_FEATURES #=> [..., "/home/trans/.local/lib/ry/rubies/1.9.3-p125/lib/ruby/1.9.1/ostruct.rb"] path = require_path('ostruct') #=> "/home/trans/.local/lib/ry/rubies/1.9.3-p125/lib/ruby/1.9.1/ostruct.rb" $LOADED_FEATURES.include?(path) Of course, it would be nice to also have: required?('ostruct') #=> true These methods could be class methods of special module, if it's important to keep the Kernel more tidy, e.g. `Ruby.required?('ostruct')`. I am currently working on a project where I need this (and have a couple of other projects that could use it too) and I've had to implement the whole thing from scratch, which isn't simple, nor fast, nor am I 100% confident that it specs exactly to Ruby's own lookup procedure. So it would be much better if Ruby would expose its lookup functionality. -- http://bugs.ruby-lang.org/