-
Notifications
You must be signed in to change notification settings - Fork 21.7k
New issue
Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.
By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.
Already on GitHub? Sign in to your account
Add Array#extract!
#33137
Add Array#extract!
#33137
Conversation
r? @schneems (@rails-bot has picked a reviewer for you, use r? to override) |
I'm ok with this one. @dhh what do you think of this name? |
I honestly thought that this is what |
FWIW, it would be named
💯. This was very helpful, thank you. On the implementation: I'd like to avoid allocating the second array. What do you think of something like Let's also avoid |
Thanks for the review guys! @matthewd I applied your suggestions in Refactor
I prepared benchmarks in order to ensure that the changes speed up the method: (Not sure that these benchmarks are completely right) begin
require "bundler/inline"
rescue LoadError => e
$stderr.puts "Bundler version 1.10 or later is required. Please update
your Bundler"
raise e
end
class Array
def extract_v1!(&block)
unless block_given?
to_enum(:extract!) { size }
else
extracted_elements, other_elements = partition(&block)
replace(other_elements)
extracted_elements
end
end
def extract_v2!
return to_enum(:extract!) { size } unless block_given?
extracted_elements = []
reject! do |element|
extracted_elements << element if yield(element)
end
extracted_elements
end
end
gemfile(true) do
source "https://rubygems.org"
gem "benchmark-ips"
end
arrays_for_partition = Array.new(1000) { (0..10000).to_a }
arrays_for_extract_v1 = Array.new(1000) { (0..10000).to_a }
arrays_for_extract_v2 = Array.new(1000) { (0..10000).to_a }
Benchmark.ips do |x|
x.report("Array#partition") do
arrays_for_partition.each do |numbers|
odd_numbers, numbers = numbers.partition { |number| number.odd? }
numbers
end
end
x.report("Array#extract_v1!") do
arrays_for_extract_v1.each do |numbers|
odd_numbers = numbers.extract_v1! { |number| number.odd? }
numbers
end
end
x.report("Array#extract_v2!") do
arrays_for_extract_v2.each do |numbers|
odd_numbers = numbers.extract_v2! { |number| number.odd? }
numbers
end
end
x.compare!
end The result of the benchmarks: ruby -v
ruby 2.5.1p57 (2018-03-29 revision 63029) [x86_64-linux] Fetching gem metadata from https://rubygems.org/.
Resolving dependencies...
Using benchmark-ips 2.7.2
Using bundler 1.16.1
Warming up --------------------------------------
Array#partition 1.000 i/100ms
Array#extract_v1! 1.000 i/100ms
Array#extract_v2! 1.000 i/100ms
Calculating -------------------------------------
Array#partition 1.390 (± 0.0%) i/s - 7.000 in 5.044843s
Array#extract_v1! 2.781 (± 0.0%) i/s - 14.000 in 5.050589s
Array#extract_v2! 3.151 (± 0.0%) i/s - 16.000 in 5.080608s
Comparison:
Array#extract_v2!: 3.2 i/s
Array#extract_v1!: 2.8 i/s - 1.13x slower
Array#partition: 1.4 i/s - 2.27x slower
Yeah, It will be more readable and also using of early return would improve |
I rerun the test case (twice, in the span of 6 days ..ha) and it is now passing. @matthewd @rafaelfranca would either of you mind merging this in if this is good to go? |
0a8e9ef
to
58abeed
Compare
The method removes and returns the elements for which the block returns a true value. If no block is given, an Enumerator is returned instead. ``` numbers = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] odd_numbers = numbers.extract! { |number| number.odd? } # => [1, 3, 5, 7, 9] numbers # => [0, 2, 4, 6, 8] ```
Avoid allocating the second array by using `Array#reject!` instead of `Enumerable#partition` in `Array#extract!`. There are benchmarks in order to ensure that the changes speed up the method: ``` begin require "bundler/inline" rescue LoadError => e $stderr.puts "Bundler version 1.10 or later is required. Please update your Bundler" raise e end class Array def extract_v1!(&block) unless block_given? to_enum(:extract!) { size } else extracted_elements, other_elements = partition(&block) replace(other_elements) extracted_elements end end def extract_v2! return to_enum(:extract!) { size } unless block_given? extracted_elements = [] reject! do |element| extracted_elements << element if yield(element) end extracted_elements end end gemfile(true) do source "https://rubygems.org" gem "benchmark-ips" end arrays_for_partition = Array.new(1000) { (0..10000).to_a } arrays_for_extract_v1 = Array.new(1000) { (0..10000).to_a } arrays_for_extract_v2 = Array.new(1000) { (0..10000).to_a } Benchmark.ips do |x| x.report("Array#partition") do arrays_for_partition.each do |numbers| odd_numbers, numbers = numbers.partition { |number| number.odd? } numbers end end x.report("Array#extract_v1!") do arrays_for_extract_v1.each do |numbers| odd_numbers = numbers.extract_v1! { |number| number.odd? } numbers end end x.report("Array#extract_v2!") do arrays_for_extract_v2.each do |numbers| odd_numbers = numbers.extract_v2! { |number| number.odd? } numbers end end x.compare! end ``` The result of the benchmarks: ``` ruby -v ruby 2.5.1p57 (2018-03-29 revision 63029) [x86_64-linux] ``` ``` Fetching gem metadata from https://rubygems.org/. Resolving dependencies... Using benchmark-ips 2.7.2 Using bundler 1.16.1 Warming up -------------------------------------- Array#partition 1.000 i/100ms Array#extract_v1! 1.000 i/100ms Array#extract_v2! 1.000 i/100ms Calculating ------------------------------------- Array#partition 1.390 (± 0.0%) i/s - 7.000 in 5.044843s Array#extract_v1! 2.781 (± 0.0%) i/s - 14.000 in 5.050589s Array#extract_v2! 3.151 (± 0.0%) i/s - 16.000 in 5.080608s Comparison: Array#extract_v2!: 3.2 i/s Array#extract_v1!: 2.8 i/s - 1.13x slower Array#partition: 1.4 i/s - 2.27x slower ``` Avoid `unless`/`else` in favour of an early return. The double-negative of that `else` can be confusing, even though the code layout is nearly the same. Also using of early return would improve `git diff` if we needed to change this method.
58abeed
to
b71abb3
Compare
The method removes and returns the elements for which the block returns a true value.
If no block is given, an Enumerator is returned instead.
Also, I added commit Use
Array#extract!
where possible in order to show that we can improve Rails code base by this method.Looks more readable if use
Array#extract!
, doesn't it?I know we try to omit adding new methods to ActiveSupport, but I think this one has a good chance to be added since we can apply it in Rails code base.
By the way, we already added
Hash#extract!
https://github.com/rails/rails/blob/master/activesupport/lib/active_support/core_ext/hash/slice.rb#L41-L47
Post: https://gitlab.com/bogdanvlviv/posts/-/issues/14, https://bogdanvlviv.com/posts/ruby/rails/array-extract-to-activesupport-6-0.html
I have tried to add Active Support's
Array#extract!
asArray#extract
to Ruby, see Feature #15831: "AddArray#extract
,Hash#extract
, andENV.extract
".Thanks!