From: non.dmitriy@gmail.com
To: ruby-core@ruby-lang.org
Subject: [ruby-core:95794] [Ruby master Feature#16341] Proposal: Set#to_proc
Date: Mon, 11 Nov 2019 15:37:10 +0000 (UTC) [thread overview]
Message-ID: <redmine.journal-82615.20191111153710.8a939319540f3104@ruby-lang.org> (raw)
In-Reply-To: redmine.issue-16341.20191111150227@ruby-lang.org
Issue #16341 has been updated by Nondv (Dmitry Non).
Well, to be fair, this change is just nice-to-have sugar. I don't expect it to become a thing.
I guess for now the best way to do that is:
```ruby
pets.count { |x| dogs.include?(x) }
# or
pets.count(&dogs.method(:include?))
```
They both are "more clear than value-object-suddenly-becoming-procs". But having implicit conversion would be just a nice feature to make code more compact and expressive (MHO).
Clojure treats sets as functions, btw:
```clojure
(def dogs #{:labrador :husky :bullterrier :corgi})
(count (filter dogs [:parrot :labrador :goldfish :husky :labrador :turtle]))
```
----------------------------------------
Feature #16341: Proposal: Set#to_proc
https://bugs.ruby-lang.org/issues/16341#change-82615
* Author: Nondv (Dmitry Non)
* Status: Open
* Priority: Normal
* Assignee:
* Target version:
----------------------------------------
``` ruby
class Set
def to_proc
-> (x) { include?(x) } # or method(:include?).to_proc
end
end
```
Usage:
```ruby
require 'set'
banned_numbers = Set[0, 5, 7, 9]
(1..10).reject(&banned_numbers) # ===> [1, 2, 3, 4, 6, 8, 10]
```
--
https://bugs.ruby-lang.org/
next prev parent reply other threads:[~2019-11-11 15:37 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <redmine.issue-16341.20191111150227@ruby-lang.org>
2019-11-11 15:02 ` [ruby-core:95789] [Ruby master Bug#16341] Proposal: Set#to_proc non.dmitriy
2019-11-11 15:08 ` [ruby-core:95790] [Ruby master Feature#16341] " zverok.offline
2019-11-11 15:18 ` [ruby-core:95791] " non.dmitriy
2019-11-11 15:26 ` [ruby-core:95793] " zverok.offline
2019-11-11 15:37 ` non.dmitriy [this message]
2019-11-11 23:43 ` [ruby-core:95804] " shevegen
2019-11-12 18:58 ` [ruby-core:95819] " non.dmitriy
2019-11-12 19:05 ` [ruby-core:95820] " non.dmitriy
2019-11-12 19:09 ` [ruby-core:95821] " non.dmitriy
2019-11-12 19:44 ` [ruby-core:95822] [Ruby master Feature#16341] Proposal: Set#to_proc and Hash#to_proc shannonskipper
2019-11-12 20:12 ` [ruby-core:95823] " non.dmitriy
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