[#51329] [ruby-trunk - Feature #7677][Open] YAML load mode that does instantiate Ruby — "trans (Thomas Sawyer)" <transfire@...>
7 messages
2013/01/09
[#51347] [ruby-trunk - Bug #7679][Open] IRB history is broken — "zzak (Zachary Scott)" <zachary@...>
15 messages
2013/01/10
[#51348] [ruby-trunk - Bug #7680][Open] IRB autocompletion doesn't autocomplete methods — "zzak (Zachary Scott)" <zachary@...>
8 messages
2013/01/10
[#51389] [ruby-trunk - Bug #7688][Open] Error hiding with rb_rescue() on Comparable#==, #coerce and others — "Eregon (Benoit Daloze)" <redmine@...>
34 messages
2013/01/11
[#59674] [ruby-trunk - Feature #7688] Error hiding with rb_rescue() on Comparable#==, #coerce and others
— "marcandre (Marc-Andre Lafortune)" <ruby-core@...>
2014/01/09
[#59675] [ruby-trunk - Feature #7688] Error hiding with rb_rescue() on Comparable#==, #coerce and others
— "marcandre (Marc-Andre Lafortune)" <ruby-core@...>
2014/01/09
[#59679] Re: [ruby-trunk - Feature #7688] Error hiding with rb_rescue() on Comparable#==, #coerce and others
— "Martin J. Dürst" <duerst@...>
2014/01/10
On 2014/01/10 7:42, marcandre (Marc-Andre Lafortune) wrote:
[#51391] [ANN] Implementer Meeting — Aaron Patterson <tenderlove@...>
Hey everyone,
9 messages
2013/01/11
[#51421] Re: [ANN] Implementer Meeting
— Mark Rada <markrada26@...>
2013/01/14
Hello Aaron,
[#51431] Re: [ANN] Implementer Meeting
— Marc-Andre Lafortune <ruby-core-mailing-list@...>
2013/01/14
I'm worried about issues with Enumerator::Lazy. Should we discuss this at
[#51399] [ruby-trunk - Bug #7689][Open] Crash @enumerator.so with ruby 1.9.3/thin/RoR 3.2.11 — "saepia (Marcin Lewandowski)" <marcin@...>
6 messages
2013/01/12
[#51441] [ruby-trunk - Bug #7699][Open] rubyspec failed: BigDecimal#divmod Can be reversed with * and + — "mrkn (Kenta Murata)" <muraken@...>
8 messages
2013/01/15
[#51453] [REMINDER] Implemeter Meeting — Aaron Patterson <tenderlove@...>
Hey everyone,
5 messages
2013/01/15
[#51454] [CommonRuby - Feature #7701][Open] Non-optional (required) keyword args — "headius (Charles Nutter)" <headius@...>
31 messages
2013/01/15
[#53256] [CommonRuby - Feature #7701] Non-optional (required) keyword args
— "headius (Charles Nutter)" <headius@...>
2013/03/09
[#51496] Ruby 2.0 Meeting Schedule — Aaron Patterson <tenderlove@...>
At the Implemeters Meeting, we talked about meeting again in 2 weeks
5 messages
2013/01/17
[#51497] Schedule next developer meeting — Aaron Patterson <tenderlove@...>
At the last meeting, we agreed upon having another meeting four weeks
5 messages
2013/01/17
[#51499] [ruby-trunk - Feature #7712][Open] Add .txt extensions to all plain-text documentation files for Windows users — "postmodern (Hal Brodigan)" <postmodern.mod3@...>
9 messages
2013/01/18
[#51545] Haiku port problem — Paulo Geyer <paulogeyer@...>
I'm trying to port ruby 1.9.3-p347 to Haiku (http://www.haiku-os.org/)
5 messages
2013/01/21
[#51578] [ruby-trunk - Bug #7729][Open] __dir__ returns a absolute dir path — "authorNari (Narihiro Nakamura)" <authorNari@...>
8 messages
2013/01/23
[#51623] [ruby-trunk - Feature #7739][Open] Define Hash#| as Hash#reverse_merge in Rails — "alexeymuranov (Alexey Muranov)" <redmine@...>
24 messages
2013/01/24
[#51726] [ruby-trunk - Feature #7751][Open] How to encapsulate File.delete and File.rename into one 'transaction'? — "mghomn (Justin Peal)" <yujianbin@...>
5 messages
2013/01/29
[#51735] [ruby-trunk - Bug #7752][Open] Rational/Float/Fixnum/Bignum `.to_s.encoding` is US-ASCII — "coffeejunk (Maximilian Haack)" <mxhaack@...>
6 messages
2013/01/29
[ruby-core:51661] [ruby-trunk - Bug #7715][Assigned] Lazy enumerators should want to stay lazy.
From:
"marcandre (Marc-Andre Lafortune)" <ruby-core@...>
Date:
2013-01-25 06:20:04 UTC
List:
ruby-core #51661
Issue #7715 has been updated by marcandre (Marc-Andre Lafortune).
Status changed from Open to Assigned
Assignee set to marcandre (Marc-Andre Lafortune)
I can do it, unless there are objections.
----------------------------------------
Bug #7715: Lazy enumerators should want to stay lazy.
https://bugs.ruby-lang.org/issues/7715#change-35625
Author: marcandre (Marc-Andre Lafortune)
Status: Assigned
Priority: Normal
Assignee: marcandre (Marc-Andre Lafortune)
Category: core
Target version: 2.0.0
ruby -v: r38825
I'm just waking up to the fact that many methods turn a lazy enumerator in a non-lazy one.
Here's an example from Benoit Daloze in [ruby-core:44151]:
lines = File.foreach('a_very_large_file').lazy
.select {|line| line.length < 10 }
.map {|line| line.chomp!; line }
.each_slice(3)
.map {|lines| lines.join(';').downcase }
.take_while {|line| line.length > 20 }
That code will produce the right result but *will read the whole file*, which is not what is desired
Indeed, `each_slice` currently does not return a lazy enumerator :-(
To make the above code as intended, one must call `.lazy` right after the `each_slice(3)`. I feel this is dangerous and counter intuitive.
Is there a valid reason for this behavior? Otherwise, I would like us to consider returning a lazy enumerator for the following methods:
(when called without a block)
each_with_object
each_with_index
each_slice
each_entry
each_cons
(always)
chunk
slice_before
The arguments are:
* fail early (much easier to realize one needs to call a final `force`, `to_a` or `each` than realizing that a lazy enumerator chain isn't actually lazy)
* easier to remember (every method normally returning an enumerator returns a lazy enumerator). basically this makes Lazy covariant
* I'd expect that if you get lazy at some point, you typically want to remain lazy until the very end
--
http://bugs.ruby-lang.org/