From: duerst@...
Date: 2014-12-17T06:46:30+00:00
Subject: [ruby-core:66898] [ruby-trunk - Bug #10450] multiple assignment in	conditional

Issue #10450 has been updated by Martin D��rst.


It seems that both Matz and I got confused. That's not too surprising because the first example has no parentheses.

I suggest the following:

- Create a new issue that strictly concentrates on the case WITH parentheses.

- Beef up the pull request with the necessary changes to tests.

Please note that Matz can still reject the issue if he doesn't like it (e.g. because he feels it's too confusing,...).

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Bug #10450: multiple assignment in conditional
https://bugs.ruby-lang.org/issues/10450#change-50449

* Author: bug hit
* Status: Rejected
* Priority: Normal
* Assignee: 
* Category: 
* Target version: 
* ruby -v: ruby 2.1.4p265 (2014-10-27 revision 48166) [x86_64-linux]
* Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN
----------------------------------------
multiple assignment is an expression whose value can be truthy (array) or falsy (nil, false), so why is there a restriction on its use in conditionals?  A warning perhaps is justified, but a syntax error, why?


irb(main):001:0> if a, b = nil then 1 else 0 end
SyntaxError: (irb):1: syntax error, unexpected ',', expecting keyword_then or ';' or '\n'
if a, b = nil then 1 else 0 end
     ^
(irb):1: syntax error, unexpected keyword_then, expecting end-of-input
if a, b = nil then 1 else 0 end
                  ^
	from /home/alex/.rbenv/versions/2.1.4/bin/irb:11:in `<main>'
irb(main):002:0> if (a, b = nil) then 1 else 0 end
SyntaxError: (irb):2: multiple assignment in conditional
	from /home/alex/.rbenv/versions/2.1.4/bin/irb:11:in `<main>'
irb(main):003:0> (a, b = nil) ? 1 : 0
SyntaxError: (irb):3: multiple assignment in conditional
	from /home/alex/.rbenv/versions/2.1.4/bin/irb:11:in `<main>'
irb(main):004:0> (a, b = nil)
=> nil




-- 
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