Bug #6428: lazy版take/dropに2度forceを呼んだ時の挙動

• Status: Closed
• Assignee: nagachika (Tomoyuki Chikanaga)
• Target version: 2.0.0
• ruby -v: ruby 2.0.0dev (2012-05-12 trunk 35629) [x86_64-darwin10.8.0]

[nagachika (Tomoyuki Chikanaga)]

Enumerator::Lazy#take が返す Enumerator::Lazy に繰り返し force/to_a メソッドを呼ぶと、
2度目以降は全ての要素を返しています。

$ cat lazy_take_recycle.rb
lazy_take = (1..5).lazy.take(3)

p lazy_take.force
p lazy_take.force

$ ruby lazy_take_recycle.rb
[1, 2, 3]
[1, 2, 3, 4, 5]

同じ Enumerator::Lazy に force を複数回呼ぶのがよい使いかたではないのかもしれませんが、
なんとなく何度呼んでも先頭の要素を返してくれるのが嬉しいのではないかと思います。
2度目以降も同じ個数になるようにするパッチを添付します。
ただし実用的なユースケースがあるわけではありません。

[matz (Yukihiro Matsumoto)]

• Assignee set to nagachika (Tomoyuki Chikanaga)

コミットしてください。

[nagachika (Tomoyuki Chikanaga)]

• Status changed from Open to Closed
• % Done changed from 0 to 100

This issue was solved with changeset r35638.
Tomoyuki, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.

---

• enumerator.c (lazy_take_func, lazy_take): multiple calls of
  force/to_a method to Enumerator::Lazy#take should return same
  results. [ruby-dev:45634] [Bug #6428]

• test/ruby/test_lazy_enumerator.rb (test_take_recycle): add test for
  above.

[nagachika (Tomoyuki Chikanaga)]

• enumerator.c (lazy_take_func, lazy_take): multiple calls of
  force/to_a method to Enumerator::Lazy#take should return same
  results. [ruby-dev:45634] [Bug #6428]

• test/ruby/test_lazy_enumerator.rb (test_take_recycle): add test for
  above.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@35638 b2dd03c8-39d4-4d8f-98ff-823fe69b080e