From: Thomas Sawyer <transfire@...>
Date: 2012-03-17T00:55:52+09:00
Subject: [ruby-core:43351] [ruby-trunk - Bug #6158] Enumerator::Lazy#take: should it be lazy?


Issue #6158 has been updated by Thomas Sawyer.


Both "takes" on this seem valid. Could there be a special method similar to take for de-lazying and taking a segment of the enumeration? e.g. maybe #pinch ?

    e.lazy.pinch(3)

    e.lazy.pinch(4..6)

    e.lazy.pinch(2, 4)


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Bug #6158: Enumerator::Lazy#take: should it be lazy?
https://bugs.ruby-lang.org/issues/6158#change-24655

Author: Benoit Daloze
Status: Assigned
Priority: Normal
Assignee: Shugo Maeda
Category: 
Target version: 
ruby -v: ruby 2.0.0dev (2012-03-15 trunk 35042) [x86_64-darwin10.8.0]


Hello,

I noticed #take is now defined on Enumerator::Lazy, and it has lazy behavior:

    (1..1000).lazy.select(&:even?).take 3 # => #<Enumerator::Lazy ...>

I would expect #take to not be lazy and always produce an Array, like the original Enumerable#take does.
I think many rubyists would expect that too.

Do you have a use case for a lazy #take ? I can't find one right now.

I've seen #6152, although I can't read it.
I think `lazy.take(5)` should be equal to `lazy.first(5)` and it reads better.


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