[#58149] [ruby-trunk - Feature #9076][Open] New one-argument block syntax: &. — "asterite (Ary Borenszweig)" <ary@...>

23 messages 2013/11/04

[#58176] [ruby-trunk - Bug #9082][Open] popen3 hangs when stderr gets lots of output — "rosenfeld (Rodrigo Rosenfeld Rosas)" <rr.rosas@...>

15 messages 2013/11/05

[#58207] [ruby-trunk - Bug #9089][Open] rb_fix2uint no longer raises a RangeError when given negative values — "NoKarma (Arthur Schreiber)" <schreiber.arthur@...>

9 messages 2013/11/06

[#58243] [ruby-trunk - Feature #9098][Open] Indent heredoc against the left margin by default when "indented closing identifier" is turned on. — "sikachu (Prem Sichanugrist)" <s@...>

24 messages 2013/11/09

[#58306] [ruby-trunk - Bug #9106][Open] 'gem install' doesn't copy .so files of ext libs — "tagomoris (Satoshi TAGOMORI)" <tagomoris@...>

15 messages 2013/11/13

[#58324] [ruby-trunk - Feature #9108][Open] Hash sub-selections — "wardrop (Tom Wardrop)" <tom@...>

28 messages 2013/11/14

[#58342] [ruby-trunk - Feature #9112][Open] Make module lookup more dynamic (Including modules into a module after it has already been included) — "PragTob (Tobias Pfeiffer)" <pragtob@...>

16 messages 2013/11/14

[#58350] [ruby-trunk - Feature #9113][Open] Ship Ruby for Linux with jemalloc out-of-the-box — "sam.saffron (Sam Saffron)" <sam.saffron@...>

59 messages 2013/11/15

[#58374] [ruby-trunk - Bug #9115][Open] Logger traps all exceptions; breaks Timeout — "cphoenix (Chris Phoenix)" <cphoenix@...>

10 messages 2013/11/16

[#58375] [ruby-trunk - Feature #9116][Open] String#rsplit missing — "artagnon (Ramkumar Ramachandra)" <artagnon@...>

12 messages 2013/11/16

[#58396] [ruby-trunk - Bug #9121][Open] [PATCH] Remove rbtree implementation of SortedSet due to performance regression — "xshay (Xavier Shay)" <contact@...>

15 messages 2013/11/18

[#58404] [ruby-trunk - Feature #9123][Open] Make Numeric#nonzero? behavior consistent with Numeric#zero? — "sferik (Erik Michaels-Ober)" <sferik@...>

40 messages 2013/11/18

[#58411] [ruby-trunk - Bug #9124][Open] TestSocket errors in test-all on Arch 64-bit — "jonforums (Jon Forums)" <redmine@...>

14 messages 2013/11/18

[#58438] [ruby-trunk - Bug #9129][Open] Regression in support for IPv6 literals in URIs with Net::HTTP — "kallistec (Daniel DeLeo)" <dan@...>

11 messages 2013/11/19

[#58545] [ruby-trunk - Feature #9145][Open] Queue#pop(true) return nil if empty instead of raising ThreadError — "jsc (Justin Collins)" <redmine@...>

9 messages 2013/11/24

[#58653] [ruby-trunk - Bug #9170][Open] Math.sqrt returns different types when mathn is included; breaks various gems - this bug can be reproduced in Ruby 1.8 as well — "kranzky (Jason Hutchens)" <JasonHutchens@...>

7 messages 2013/11/28

[ruby-core:58498] [ruby-trunk - Feature #9123] Make Numeric#nonzero? behavior consistent with Numeric#zero?

From: "mame (Yusuke Endoh)" <mame@...>
Date: 2013-11-22 13:59:47 UTC
List: ruby-core #58498
Issue #9123 has been updated by mame (Yusuke Endoh).


I don't think it is possible to change the spec.
Many programs in the wild actually use the behavior.

https://github.com/search?q=nonzero%3F+sort+extension%3Arb&type=Code



By the way, I investigated the early history of nonzero?.


In the beginning, Nagai proposed a "<>" operator that returns -1, nil, 1
in [ruby-list:7286] (1 Apr 1998).  The motivation example was:

  def struct_cmp (a, b)
     (a.mem_a <> a.mem_a) || (a.mem_b <=> a.mem_b)
  end

Obviously he had in mind Perl's common idiom for lexicographic sort:

  sort { a[0] <=> b[0] || a[1] <=> b[1] }

because it is 1998 :-)


Matz said he was negative to this proposal in [ruby-list:7286] because
it would make the language complex to add a new operator, and because
he thought that it would be better to change the boolean semantics,
that is, to handle 0 as false (!).


Nagai, in [ruby-dev:2026], disagreed with the semantic change because of
a philosophical reason (it looked weird to him to handle only one instance
of Integer as false), and reclaimed adding a new operator.


In [ruby-dev:2031], Funaba disagreed with a new operator because the
lexicographic sort is not a common operation, he thought.
He also disagreed with the semantic change because of a compatibility
issue (in spite of 1998).
And then, nonzero? appeared in the counter-proposal he made:

  (a <=> b).nonzero? || (a2 <=> b2)


Matz liked and implemented the proposal in a day [ruby-dev:2046].


Because nonzero? was accepted, a "<>" operator became less significant.
Nagai, in [ruby-dev:2050], dismissed his proposal.

In the mail, he pointed the inconsistency that is now discussed in this
ticket.  He asked why matz implemented not only nonzero? but also zero?.
Matz's answer was:

- symmetry of zero? and nonzero?
- lisp/scheme provides zero?

(According to this history, it makes no sense to fit nonzero? with zero?.)


Incidentally, the discussion continued, and Keiju proposed Array#<=> in
[ruby-dev:2101], that is,

  [a1, a2] <=> [b1, b2]

After the further discussion, this was accepted too.

Funaba, who proposed nonzero? himself, preferred Array#<=> to nonzero?,
but also pointed out that Array#<=> is not a perfect substitute to
nonzero? because Array#<=> does not shortcut.


After that, nonzero? exists until now.

-- 
Yusuke Endoh <[email protected]>
----------------------------------------
Feature #9123: Make Numeric#nonzero? behavior consistent with Numeric#zero?
https://bugs.ruby-lang.org/issues/9123#change-43083

Author: sferik (Erik Michaels-Ober)
Status: Open
Priority: Normal
Assignee: 
Category: 
Target version: 


Numeric#zero? returns true or false, while Numeric#nonzero? returns self or nil.

I've written a patch that fixes this inconsistency and adds a Numeric#nonzero (non-predicate) method that returns self or nil for chaining comparisons. I'd like for this to be included in Ruby 2.1.0.

https://github.com/ruby/ruby/pull/452.patch


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

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