From: mail@stefanschuessler.de
To: ruby-core@ruby-lang.org
Subject: [ruby-core:90913] [Ruby trunk Misc#15514] Add documentation for implicit array decomposition
Date: Mon, 07 Jan 2019 10:26:52 +0000 (UTC) [thread overview]
Message-ID: <redmine.issue-15514.20190107102651.f011fdc6de4fe46f@ruby-lang.org> (raw)
In-Reply-To: redmine.issue-15514.20190107102651@ruby-lang.org
Issue #15514 has been reported by sos4nt (Stefan Schüßler).
----------------------------------------
Misc #15514: Add documentation for implicit array decomposition
https://bugs.ruby-lang.org/issues/15514
* Author: sos4nt (Stefan Schüßler)
* Status: Open
* Priority: Normal
* Assignee:
----------------------------------------
The documentation for [Array Decomposition](http://ruby-doc.org/core/doc/syntax/assignment_rdoc.html#label-Array+Decomposition) says: _"[...] you can decompose an Array during assignment using parenthesis [sic]"_ and gives an example:
```ruby
(a, b) = [1, 2]
p a: a, b: b # prints {:a=>1, :b=>2}
```
But – as we all know – it's also possible _without_ parentheses, i.e.
```ruby
a, b = [1, 2]
p a: a , b: b #=> {:a=>1, :b=>2}
```
This also applies to block arguments when yielding multiple values vs. yielding a single array:
```ruby
def foo
yield 1, 2
end
def bar
yield [1, 2]
end
foo { |a, b| p a: a, b: b }
#=> {:a=>1, :b=>2}
bar { |a, b| p a: a, b: b }
#=> {:a=>1, :b=>2}
```
In both cases, parentheses are optional.
This implicit array decomposition could be quite surprising for newcomers. The documentation should cover it.
--
https://bugs.ruby-lang.org/
next parent reply other threads:[~2019-01-07 10:26 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <redmine.issue-15514.20190107102651@ruby-lang.org>
2019-01-07 10:26 ` mail [this message]
2019-01-07 11:10 ` [ruby-core:90914] [Ruby trunk Misc#15514] Add documentation for implicit array decomposition shevegen
2019-01-10 16:43 ` [ruby-core:91004] " lisa.ugray
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