ruby-core

Issue #15708 has been updated by sholden (Scott Holden).


Eregon (Benoit Daloze) wrote:
> FWIW, I would bet >99% of Rubyists would agree this is a bug: https://twitter.com/eregontp/status/1115318993299083265


This is definitely not the behavior I would expect. In everything that I've seen, developers are describing the feature such that 

``` ruby
a.map{|x| x} == a.map{ @1 }
```

This would be a very surprising behavior for people to stumble upon.

----------------------------------------
Bug #15708: Implicit numbered argument decomposes an array
https://bugs.ruby-lang.org/issues/15708#change-77548

* 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
----------------------------------------
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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