From: "knu (Akinori MUSHA)" <noreply@...>
Date: 2021-09-13T04:10:25+00:00
Subject: [ruby-core:105217] [Ruby master Feature#14579] Hash value omission

Issue #14579 has been updated by knu (Akinori MUSHA).


baweaver (Brandon Weaver) wrote in #note-19:
> * `@var:` - Would this work with instance/class/global/constant variables if they're valid symbols?

No, because we didn't change the symbol key syntax.  `{ @var: @var }` is not valid, so `{ @var: }` isn't either.  The same goes for `$var` and `@@var`.

> * `a = 1; {a:, b: 3}` - Does it support mixing omissions and regular values?

Yes.

> * `p a:, b: 3` - Does it work with implied hashes / keywords? (I think yes).

Yes, but beware when you omit the last value without the closing parenthesis.  The interpreter will look further past the line end for a value.

----------------------------------------
Feature #14579: Hash value omission
https://bugs.ruby-lang.org/issues/14579#change-93624

* Author: shugo (Shugo Maeda)
* Status: Closed
* Priority: Normal
* Assignee: matz (Yukihiro Matsumoto)
----------------------------------------
How about to allow value omission in Hash literals:

```ruby
x = 1
y = 2
h = {x:, y:}
p h #=> {:x=>1, :y=>2}
```

And in keyword arguments:

```ruby
def login(username: ENV["USER"], password:)
  p(username:, password:)
end

login(password: "xxx") #=> {:username=>"shugo", :password=>"xxx"}
```


---Files--------------------------------
hash_value_omission.diff (619 Bytes)


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