From c9a5a71695af4596346e70f29dddb9ddb6106177 Mon Sep 17 00:00:00 2001
From: Takashi Kokubun <takashikkbn@gmail.com>
Date: Tue, 12 Nov 2024 20:39:32 -0800
Subject: [PATCH] Move Array#select to Ruby

Co-Authored-By: Aaron Patterson <tenderlove@ruby-lang.org>
---
 array.c  |  6 ++++++
 array.rb | 25 +++++++++++++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/array.c b/array.c
index ed7bc6ddb0..fbed28832f 100644
--- a/array.c
+++ b/array.c
@@ -6866,6 +6866,12 @@ ary_sample(rb_execution_context_t *ec, VALUE ary, VALUE randgen, VALUE nv, VALUE
     return result;
 }
 
+static VALUE
+ary_sized_alloc(rb_execution_context_t *ec, VALUE self)
+{
+    return rb_ary_new2(RARRAY_LEN(self));
+}
+
 static VALUE
 ary_sample0(rb_execution_context_t *ec, VALUE ary)
 {
diff --git a/array.rb b/array.rb
index 67eafcc81b..ec204c2478 100644
--- a/array.rb
+++ b/array.rb
@@ -232,5 +232,30 @@ class Array
         self
       end
     end
+
+    if Primitive.rb_builtin_basic_definition_p(:select)
+      undef :select
+
+      def select # :nodoc:
+        Primitive.attr! :inline_block, :c_trace
+
+        unless defined?(yield)
+          return Primitive.cexpr! 'SIZED_ENUMERATOR(self, 0, 0, ary_enum_length)'
+        end
+
+        _i = 0
+        value = nil
+        result = Primitive.ary_sized_alloc
+        while Primitive.cexpr!(%q{ ary_fetch_next(self, LOCAL_PTR(_i), LOCAL_PTR(value)) })
+          result << value if yield value
+        end
+        result
+      end
+
+      if Primitive.rb_builtin_basic_definition_p(:filter)
+        undef :filter
+        alias filter select
+      end
+    end
   end
 end