Issue #15708 has been updated by Eregon (Benoit Daloze).


FWIW, the replies on my tweet above is some good sign that very few Rubyists expect this behavior and it breaks the basics assumptions of how the feature can be used.

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Bug #15708: Implicit numbered argument decomposes an array
https://bugs.ruby-lang.org/issues/15708#change-77560

* Author: sawa (Tsuyoshi Sawada)
* Status: Open
* Priority: Normal
* Assignee: 
* Target version: 
* ruby -v: 2.7.0dev
* Backport: 2.4: UNKNOWN, 2.5: UNKNOWN, 2.6: UNKNOWN
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In the following, `@1` refers to the entire item iterated:

```ruby
a = [1, 2, 3]
a.map{|x| x} # => [1, 2, 3]
a.map{@1} # => [1, 2, 3]
```

whereas in the following, `@1` refers to the first item achieved by decomposing the item iterated, behaving the same as `x` given by `|(x)|` rather than by `|x|`:

```ruby
a = [[1], [2], [3]]
a.map{|x| x} # => [[1], [2], [3]]
a.map{|(x)| x} # => [1, 2, 3]
a.map{@1} # => [1, 2, 3]
```

Is this intended?



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