[#51213] [ruby-trunk - Bug #7645][Open] BigDecimal#== slow when compared to true/false — "mathie (Graeme Mathieson)" <mathie@...>

11 messages 2013/01/01

[#51328] [ruby-trunk - Bug #7676][Open] Comparison of Float::NAN in array behaves unexpectedly — "simonrussell (Simon Russell)" <spam+ruby@...>

11 messages 2013/01/09

[#51347] [ruby-trunk - Bug #7679][Open] IRB history is broken — "zzak (Zachary Scott)" <zachary@...>

15 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

[#51430] [ruby-trunk - Bug #7696][Open] Lazy enumerators with state can't be rewound — "marcandre (Marc-Andre Lafortune)" <ruby-core@...>

15 messages 2013/01/14

[#51437] [ruby-trunk - Bug #7698][Open] RubyGems 2.0 has an incompatibility about installation of extension libraries — "mrkn (Kenta Murata)" <muraken@...>

21 messages 2013/01/15

[#51454] [CommonRuby - Feature #7701][Open] Non-optional (required) keyword args — "headius (Charles Nutter)" <headius@...>

31 messages 2013/01/15

[#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

[#51619] [ruby-trunk - Feature #7738][Open] Deprecate Set#+ as an alias of Set#|, use it for symmetric difference. Introduce Hash#| for Hash#reverse_merge in Rails. — "alexeymuranov (Alexey Muranov)" <redmine@...>

11 messages 2013/01/24

[#51623] [ruby-trunk - Feature #7739][Open] Define Hash#| as Hash#reverse_merge in Rails — "alexeymuranov (Alexey Muranov)" <redmine@...>

24 messages 2013/01/24

[#51714] [CommonRuby - Feature #7747][Open] Expanded API for Binding semantics — "jballanc (Joshua Ballanco)" <jballanc@...>

19 messages 2013/01/27

[#51742] [ruby-trunk - Bug #7756][Open] clang 3.2 sees through UNINITIALIZED_VAR macro, gives warning — "drbrain (Eric Hodel)" <[email protected]>

10 messages 2013/01/29

[#51763] [ruby-trunk - Bug #7758][Open] Ruby on Windows crashes when active codepage is codepage 65001 and outputting unicode character — "joshc (Josh C)" <josh.nw@...>

16 messages 2013/01/30

[ruby-core:51244] [ruby-trunk - Feature #7654] Add optional code block to IO::readlines

From: "Eregon (Benoit Daloze)" <redmine@...>
Date: 2013-01-04 14:37:52 UTC
List: ruby-core #51244
Issue #7654 has been updated by Eregon (Benoit Daloze).


Why not

    File.foreach('test.rb').map { |line| line.upcase }

?
It does not create an intermediary Array.
If you need to do other operations lazily (without an intermediate result), you could use #lazy:

    File.foreach('test.rb').lazy.select { |line| line.start_with? '/' }.map { |line| line.upcase }.to_a
----------------------------------------
Feature #7654: Add optional code block to IO::readlines
https://bugs.ruby-lang.org/issues/7654#change-35210

Author: shock_one (Володимир Шацький)
Status: Open
Priority: Normal
Assignee: 
Category: core
Target version: 


Of course, we always can write something like
File.readlines('/home/shock_one/test.rb').map{ |line| line.upcase }
but this way we create unneeded intermediate array which can be pretty big.
There is also a method IO::foreach, but it doesn't collect return values.
Besides it seems pretty logical and natural to have a block in this method.


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