From: Thomas Sawyer <transfire@...>
Date: 2012-03-14T22:31:38+09:00
Subject: [ruby-core:43278] [ruby-trunk - Bug #6142] Enumerable::Lazy#zip doesn't rewind internal enumerators


Issue #6142 has been updated by Thomas Sawyer.


A touch OT, but is Brian Candler being involved in the development of this? I don't know of anyone who has discussed and worked on this topic more over the years than Brian and I think it would be most prudent to seek his consul on these matters.

(Not to speak for Brain, of course, but just saying.)

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Bug #6142: Enumerable::Lazy#zip doesn't rewind internal enumerators
https://bugs.ruby-lang.org/issues/6142#change-24578

Author: Innokenty Mikhailov
Status: Open
Priority: Normal
Assignee: 
Category: 
Target version: 
ruby -v: ruby 2.0.0dev (2012-03-14 trunk 35013) [x86_64-linux]


All enumerables passed to Enumerable::Lazy#zip are converted into lazy enumerators.
When result evaluated - ruby iterates over this enumerators while calling #next to retrieve the next value.
But those enumerators are not rewinded:

  a = (1..3).lazy.zip('a'..'z')
  a.to_a #=> [[1, "a"], [2, "b"], [3, "c"]]
  a.to_a #=> [[1, "d"], [2, "e"], [3, "f"]]

I believe that is not the desired behavior here and a.to_a should always return the same value.


-- 
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