[#43120] [ruby-trunk - Bug #6124][Open] What is the purpose of "fake" gems in Ruby — Vit Ondruch <v.ondruch@...>

27 messages 2012/03/07

[#43142] Questions about thread performance (with benchmark included) — Rodrigo Rosenfeld Rosas <rr.rosas@...>

A while ago I've written an article entitled "How Nokogiri and JRuby

10 messages 2012/03/08

[#43148] [ruby-trunk - Feature #6126][Open] Introduce yes/no constants aliases for true/false — Egor Homakov <homakov@...>

16 messages 2012/03/09

[#43238] [ruby-trunk - Feature #6130][Open] inspect using to_s is pain — Thomas Sawyer <transfire@...>

21 messages 2012/03/11

[#43313] [ruby-trunk - Feature #6150][Open] add Enumerable#grep_v — Suraj Kurapati <sunaku@...>

17 messages 2012/03/15

[#43325] [ruby-trunk - Bug #6154][Open] Eliminate extending WaitReadable/Writable at runtime — Charles Nutter <headius@...>

25 messages 2012/03/16

[#43334] [ruby-trunk - Bug #6155][Open] Enumerable::Lazy#flat_map raises an exception when an element does not respond to #each — Dan Kubb <dan.kubb@...>

9 messages 2012/03/16

[#43370] [ruby-trunk - Feature #6166][Open] Enumerator::Lazy#pinch — Thomas Sawyer <transfire@...>

15 messages 2012/03/17

[#43373] [ruby-trunk - Bug #6168][Open] Segfault in OpenSSL bindings — Nguma Abojo <git.email.address@...>

14 messages 2012/03/17

[#43454] [ruby-trunk - Bug #6174][Open] Fix collision of ConditionVariable#wait timeout and #signal (+ other cosmetic changes) — "funny_falcon (Yura Sokolov)" <funny.falcon@...>

10 messages 2012/03/18

[#43497] [ruby-trunk - Bug #6179][Open] File::pos broken in Windows 1.9.3p125 — "jmthomas (Jason Thomas)" <jmthomas@...>

24 messages 2012/03/20

[#43502] [ruby-trunk - Feature #6180][Open] to_b for converting objects to a boolean value — "AaronLasseigne (Aaron Lasseigne)" <aaron.lasseigne@...>

17 messages 2012/03/20

[#43529] [ruby-trunk - Bug #6183][Open] Enumerator::Lazy performance issue — "gregolsen (Innokenty Mikhailov)" <anotheroneman@...>

36 messages 2012/03/21

[#43543] [ruby-trunk - Bug #6184][Open] [BUG] Segmentation fault ruby 1.9.3p165 (2012-03-18 revision 35078) [x86_64-darwin11.3.0] — "Gebor (Pierre-Henry Frohring)" <frohring.pierrehenry@...>

8 messages 2012/03/21

[#43672] [ruby-trunk - Feature #6201][Open] do_something then return :special_case (include "then" operator) — "rosenfeld (Rodrigo Rosenfeld Rosas)" <rr.rosas@...>

12 messages 2012/03/26

[#43678] [ruby-trunk - Bug #6203][Open] Array#values_at does not handle ranges with end index past the end of the array — "ferrous26 (Mark Rada)" <markrada26@...>

15 messages 2012/03/26

[#43794] [ruby-trunk - Feature #6216][Open] SystemStackError backtraces should not be reduced to one line — "postmodern (Hal Brodigan)" <postmodern.mod3@...>

15 messages 2012/03/28

[#43814] [ruby-trunk - Feature #6219][Open] Return value of Hash#store — "MartinBosslet (Martin Bosslet)" <Martin.Bosslet@...>

20 messages 2012/03/28

[#43858] [ruby-trunk - Feature #6222][Open] Use ++ to connect statements — "gcao (Guoliang Cao)" <gcao99@...>

12 messages 2012/03/29

[#43904] [ruby-trunk - Feature #6225][Open] Hash#+ — "trans (Thomas Sawyer)" <transfire@...>

36 messages 2012/03/29

[#43951] [ruby-trunk - Bug #6228][Open] [mingw] Errno::EBADF in ruby/test_io.rb on ruby_1_9_3 — "jonforums (Jon Forums)" <redmine@...>

28 messages 2012/03/30

[#43996] [ruby-trunk - Bug #6236][Open] WEBrick::HTTPServer swallows Exception — "regularfry (Alex Young)" <alex@...>

13 messages 2012/03/31

[ruby-core:43770] [ruby-trunk - Feature #5372][Rejected] Promote blank? to a core protocol

From: "matz (Yukihiro Matsumoto)" <matz@...>
Date: 2012-03-27 16:30:46 UTC
List: ruby-core #43770
Issue #5372 has been updated by matz (Yukihiro Matsumoto).

Status changed from Assigned to Rejected

Let it stay in ActiveSupport.  Generally, string is string, array is array, in Ruby.

Matz.

----------------------------------------
Feature #5372: Promote blank? to a core protocol
https://bugs.ruby-lang.org/issues/5372#change-25279

Author: regularfry (Alex Young)
Status: Rejected
Priority: Normal
Assignee: matz (Yukihiro Matsumoto)
Category: core
Target version: 1.9.4


I don't think there's been a project I've used that hasn't made use of this pattern:

  if thing.nil? || thing.empty?

somewhere in its source.  This is necessary because it is idiomatic to return nil where other languages might return a null object, and there is no universal test for nullity which a user-implemented class can provide without issues.

Facets (and ActiveSupport) define a #blank? protocol which allows for the above to be replaced with:

  if thing.blank?

Being able to type this on a first iteration saves forgetting one of the cases and having to come back to fix a bug later.  For projects where I cannot directly use Facets or ActiveSupport, I always find that I rewrite a version for myself.  It would be very convenient not to have to do this every time, and this is clearly a common case, so I propose that #blank? be implemented on the following classes:

  Object: to return false
  String: aliased to #empty?
  NilClass: to return true
  TrueClass: to return false
  FalseClass: to return true
  Array: aliased to #empty?
  Hash: aliased to #empty?
  Fiber: to return !alive?
  Numeric: aliased to #zero?
  IO: aliased to #closed?
  MatchData: to return #to_s.blank?
  Process::Status: aliased to #exited?
  Range: to return self.include?(self.begin)
  Struct: subclass instances to return values.blank?
  Thread: to return !alive?
  ThreadGroup: to return list.blank?

Some of these uses aren't described by the word "blank?" very well (and ActiveSupport's String#blank? is somewhat different), so as a sub-feature I'd like to suggest "null?" as an alternative method name.

Apologies if this has been proposed and rejected before, but a quick search of redmine didn't show anything relevant.


-- 
http://bugs.ruby-lang.org/

In This Thread

Prev Next