From: 0x0dea+redmine@...
Date: 2015-06-19T22:14:15+00:00
Subject: [ruby-core:69687] [Ruby trunk - Feature #11286] [PATCH] Add case equality arity to Enumerable's sequence predicates.

Issue #11286 has been updated by D.E. Akers.

File case_equality_sequence_predicates-check_argc_before_deref.patch added

Nobuyoshi Nakada wrote:
> > ~~~diff
> > +    struct MEMO *memo = MEMO_NEW(Qtrue, *argv, 0);
> > +    rb_check_arity(argc, 0, 1);
> 
> Why dereference `argv` before checking `argc`.

I assumed `*argv` would resolve to `Qnil` in the case of no arguments, but this is indeed not the case. I have attached a modified patch which takes this into account.

----------------------------------------
Feature #11286: [PATCH] Add case equality arity to Enumerable's sequence predicates.
https://bugs.ruby-lang.org/issues/11286#change-53062

* Author: D.E. Akers
* Status: Open
* Priority: Normal
* Assignee: Yukihiro Matsumoto
----------------------------------------
## Proposal
It is proposed that `Enumerable`'s sequence predicates (`#all?`, `#any?`, `#none?`, and `#one?`) be augmented to return, in the case of a single argument, whether their query holds when each element is supplied to the argument's `#===` method.

## Rationale
`Enumerable#grep` filters by case equality, allowing us to write very natural and expressive code:

```ruby
strs.select { |str| /foo/ === str }
strs.grep(/foo/)

nums.select { |num| (5..10) === num }
nums.grep(5..10)
```

In addition to taking advantage of the versatility of case equality, it lets us do away with the syntactic noise incurred by opening a block. `#grep` is a very nice method! Let's make `#all?` and friends more like `#grep`.

---Files--------------------------------
0001-enum.c-add-case-equality-arity-to-sequence-predicates.patch (10 KB)
case_equality_sequence_predicates-check_argc_before_deref.patch (10 KB)


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