From: "zeke (Zeke Gabrielse)" <noreply@ruby-lang.org>
To: ruby-core@ruby-lang.org
Subject: [ruby-core:109813] [Ruby master Bug#18990] Pattern matching unexpectedly raises "duplicated key name" error
Date: Thu, 01 Sep 2022 15:06:06 +0000 (UTC) [thread overview]
Message-ID: <redmine.issue-18990.20220901150605.52300@ruby-lang.org> (raw)
In-Reply-To: redmine.issue-18990.20220901150605.52300@ruby-lang.org
Issue #18990 has been reported by zeke (Zeke Gabrielse).
----------------------------------------
Bug #18990: Pattern matching unexpectedly raises "duplicated key name" error
https://bugs.ruby-lang.org/issues/18990
* Author: zeke (Zeke Gabrielse)
* Status: Open
* Priority: Normal
* ruby -v: ruby 3.1.2p20 (2022-04-12 revision 4491bb740a) [x86_64-darwin19]
* Backport: 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN
----------------------------------------
I've found that sometimes, when matching nested patterns, I get an unexpected "duplicate key name" error but there's no duplicate key in any individual pattern. The "duplicated" key is actually in another pattern that's in scope, which I found was odd. (And the fix is even more odd.)
This seems like unexpected behavior to me. There's an example of this behavior below. The patterns in #all? cause the error, even though they're separate lines.
```ruby
class User
attr_reader :first_name,
:last_name
def initialize(first_name:, last_name:)
@first_name, @last_name = first_name, last_name
end
def deconstruct_keys(keys)
{ first_name:, last_name: }
end
end
users = [
User.new(first_name: 'Jane', last_name: 'Doe'),
User.new(first_name: 'Jane', last_name: 'Smith'),
]
# Fails
case users
in [{ first_name: 'John', ** }, *]
users.all? { _1 in first_name: 'John' }
in [{ first_name: 'Jane', ** }, *]
users.all? { _1 in first_name: 'Jane' } # => bug.rb:17: duplicated key name
end
```
Counterintuitively, wrapping the pattern in {} resolves the error.
```ruby
# Works
case users
in [{ first_name: 'John', ** }, *]
users.all? { _1 in { first_name: 'John' } }
in [{ first_name: 'Jane', ** }, *]
users.all? { _1 in { first_name: 'Jane' } }
end
```
Seems like a bug?
--
https://bugs.ruby-lang.org/
next parent reply other threads:[~2022-09-01 15:06 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-01 15:06 zeke (Zeke Gabrielse) [this message]
2022-09-01 20:00 ` [ruby-core:109818] [Ruby master Bug#18990] Pattern matching unexpectedly raises "duplicated key name" error henryanvyl (Henry Tseng)
2022-09-09 5:16 ` [ruby-core:109860] " ktsj (Kazuki Tsujimoto)
2022-09-10 7:12 ` [ruby-core:109868] " nagachika (Tomoyuki Chikanaga)
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