From: "mame (Yusuke Endoh)" <mame@...>
Date: 2013-11-23T10:14:37+09:00
Subject: [ruby-core:58514] [ruby-trunk - Feature #9123] Make	Numeric#nonzero? behavior consistent with Numeric#zero?


Issue #9123 has been updated by mame (Yusuke Endoh).


avit (Andrew Vit) wrote:
>     42.nonzero? #=> 42
>     0.nonzero?  #=> false


In fact, the first version of nonzero? returned self or false.

Inaba, in [ruby-dev:6417] (22 Mar 1999), suggested a convention about the usage
of nil and false.

  * if a method returns only a boolean, it should use true and false
  * if a method returns a general object but also "false" value, it should use nil

Matz accepted it, and adopted the convention to another exception, defined?.
As far as I know, this is the only spec change of nonzero? ever.


Inaba pointed out that a method whose name ends with "?" would make a user feel
that it should return only a boolean, though he also admitted that it is difficult
to change because of compatibility issue (in 1999).
Matz agreed, and said that "?" is a symbol that is "mainly used as a predicate".

-- 
Yusuke Endoh <mame@tsg.ne.jp>
----------------------------------------
Feature #9123: Make Numeric#nonzero? behavior consistent with Numeric#zero?
https://bugs.ruby-lang.org/issues/9123#change-43094

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


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