Issue #11286 has been updated by Nobuyoshi Nakada.


D.E. Akers wrote:
> I assumed `*argv` would resolve to `Qnil` in the case of no arguments, but this is indeed not the case.

Nobody guarantees it.

And argument check should be before making a memo object, I think.

~~~diff
diff --git a/enum.c b/enum.c
index c5b9d77..d6f11e5 100644
--- a/enum.c
+++ b/enum.c
@@ -1045,6 +1045,8 @@ enum_sort_by(VALUE obj)
 
 #define ENUMFUNC(name, argc) argc ? name##_eqq : rb_block_given_p() ? name##_iter_i : name##_i
 
+#define MEMO_ENUM_NEW(v1) (rb_check_arity(argc, 0, 1), MEMO_NEW((v1), (argc ? *argv : 0), 0))
+
 #define DEFINE_ENUMFUNCS(name) \
 static VALUE enum_##name##_func(VALUE result, struct MEMO *memo); \
 \
@@ -1104,8 +1106,7 @@ DEFINE_ENUMFUNCS(all)
 static VALUE
 enum_all(int argc, VALUE *argv, VALUE obj)
 {
-    struct MEMO *memo = MEMO_NEW(Qtrue, argc ? *argv : 0, 0);
-    rb_check_arity(argc, 0, 1);
+    struct MEMO *memo = MEMO_ENUM_NEW(Qtrue);
     rb_block_call(obj, id_each, 0, 0, ENUMFUNC(all, argc), (VALUE)memo);
     return memo->v1;
 }
@@ -1145,8 +1146,7 @@ DEFINE_ENUMFUNCS(any)
 static VALUE
 enum_any(int argc, VALUE *argv, VALUE obj)
 {
-    struct MEMO *memo = MEMO_NEW(Qfalse, argc ? *argv : 0, 0);
-    rb_check_arity(argc, 0, 1);
+    struct MEMO *memo = MEMO_ENUM_NEW(Qfalse);
     rb_block_call(obj, id_each, 0, 0, ENUMFUNC(any, argc), (VALUE)memo);
     return memo->v1;
 }
@@ -1438,8 +1438,7 @@ DEFINE_ENUMFUNCS(none)
 static VALUE
 enum_none(int argc, VALUE *argv, VALUE obj)
 {
-    struct MEMO *memo = MEMO_NEW(Qtrue, argc ? *argv : 0, 0);
-    rb_check_arity(argc, 0, 1);
+    struct MEMO *memo = MEMO_ENUM_NEW(Qtrue);
     rb_block_call(obj, id_each, 0, 0, ENUMFUNC(none, argc), (VALUE)memo);
     return memo->v1;
 }
~~~

----------------------------------------
Feature #11286: [PATCH] Add case equality arity to Enumerable's sequence predicates.
https://bugs.ruby-lang.org/issues/11286#change-53063

* 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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