Array#rfind #15189
Array#rfind #15189
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array.c
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| * of the collection; returns the last element for which the block returns a | ||
| * truthy value: | ||
| * | ||
| * (0..9).find {|element| element > 2} # => 3 |
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The examples need to be updated
| * (0..9).find {|element| element > 2} # => 3 | |
| * (0..9).rfind {|element| element < 5} # => 4 |
array.c
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| * (0..9).find(proc {false}) {|element| element > 12} # => false | ||
| * {foo: 0, bar: 1, baz: 2}.find {|key, value| key.start_with?('b') } # => [:bar, 1] | ||
| * {foo: 0, bar: 1, baz: 2}.find(proc {[]}) {|key, value| key.start_with?('c') } # => [] |
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It would be better to provide examples more specific to rfind, but here's a temporary fix:
| * (0..9).find(proc {false}) {|element| element > 12} # => false | |
| * {foo: 0, bar: 1, baz: 2}.find {|key, value| key.start_with?('b') } # => [:bar, 1] | |
| * {foo: 0, bar: 1, baz: 2}.find(proc {[]}) {|key, value| key.start_with?('c') } # => [] | |
| * (0..9).rfind(proc {false}) {|element| element > 12} # => false | |
| * {foo: 0, bar: 1, baz: 2}.rfind {|key, value| key.start_with?('b') } # => [:baz, 2] | |
| * {foo: 0, bar: 1, baz: 2}.rfind(proc {[]}) {|key, value| key.start_with?('c') } # => [] |
test/ruby/test_array.rb
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| def test_rfind | ||
| ary = [1, 2, 3, 1, 2] | ||
| assert_equal(2, ary.rfind {|x| x % 2 == 0 }) |
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I see this test was ported from test_enum.rb, but shouldn't we add tests to verify behavior specific to rfind? This test doesn't distinguish which 2 is returned and doesn't express the difference from find.
array.c
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| * | ||
| * Returns the first element for which the block returns a truthy value. | ||
| * | ||
| * With a block given, calls the block with successive elements of the collection; |
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nitpicking: in Enumerable, it seems the word "collection" refers to the objects yielded by each method. However, I feel this word slightly off in Array. In fact, the word "collection" hardly appears at all in array.c.
As defined below, "elements" seems like a better choice.
Lines 8264 to 8265 in bec6961
Well, since it says "collection of objects", you could say it's not incorrect, though. Also, "successive elements of the elements" may be awkward. I cannot think of a better phrase. Just for your reference.
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I don't think you can cache |
Implement Array#rfind, which is the same as find except from the other side of the Array. Also implemented Array#find (as opposed to the generic one on Enumerable because it is significantly faster and to keep the implementations together. [Feature #21678]
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Thanks @mame and @luke-gruber — I believe I've addressed both your comments. |
Implement Array#rfind, which is the same as find except from the other side of the Array. Also implemented Array#find (as opposed to the generic one on Enumerable because it is significantly faster and to keep the implementations together.
[Feature #21678]