ruby-changes:48290
From: marcandre <ko1@a...>
Date: Wed, 25 Oct 2017 03:08:09 +0900 (JST)
Subject: [ruby-changes:48290] marcandRe: r60404 (trunk): lib/weakref: Remove incorrect example [DOC] [Bug #14031]
marcandre 2017-10-25 03:08:00 +0900 (Wed, 25 Oct 2017) New Revision: 60404 https://svn.ruby-lang.org/cgi-bin/viewvc.cgi?view=revision&revision=60404 Log: lib/weakref: Remove incorrect example [DOC] [Bug #14031] Modified files: trunk/lib/weakref.rb Index: lib/weakref.rb =================================================================== --- lib/weakref.rb (revision 60403) +++ lib/weakref.rb (revision 60404) @@ -15,53 +15,6 @@ require "delegate" https://github.com/ruby/ruby/blob/trunk/lib/weakref.rb#L15 # GC.start # start the garbage collector # p foo.to_s # should raise exception (recycled) # -# == Example -# -# With help from WeakRef, we can implement our own rudimentary WeakHash class. -# -# We will call it WeakHash, since it's really just a Hash except all of it's -# keys and values can be garbage collected. -# -# require 'weakref' -# -# class WeakHash < Hash -# def []= key, obj -# super WeakRef.new(key), WeakRef.new(obj) -# end -# end -# -# This is just a simple implementation, we've opened the Hash class and changed -# Hash#store to create a new WeakRef object with +key+ and +obj+ parameters -# before passing them as our key-value pair to the hash. -# -# With this you will have to limit your self to String keys, otherwise you -# will get an ArgumentError because WeakRef cannot create a finalizer for a -# Symbol. Symbols are immutable and cannot be garbage collected. -# -# Let's see it in action: -# -# omg = "lol" -# c = WeakHash.new -# c['foo'] = "bar" -# c['baz'] = Object.new -# c['qux'] = omg -# puts c.inspect -# #=> {"foo"=>"bar", "baz"=>#<Object:0x007f4ddfc6cb48>, "qux"=>"lol"} -# -# # Now run the garbage collector -# GC.start -# c['foo'] #=> nil -# c['baz'] #=> nil -# c['qux'] #=> nil -# omg #=> "lol" -# -# puts c.inspect -# #=> WeakRef::RefError: Invalid Reference - probably recycled -# -# You can see the local variable +omg+ stayed, although its reference in our -# hash object was garbage collected, along with the rest of the keys and -# values. Also, when we tried to inspect our hash, we got a WeakRef::RefError. -# This is because these objects were also garbage collected. class WeakRef < Delegator -- ML: ruby-changes@q... Info: http://www.atdot.net/~ko1/quickml/