mirror of
https://github.com/mruby/mruby
synced 2026-06-08 16:11:16 +00:00
Yukihiro "Matz" Matsumoto
54 lines
1.2 KiB
Ruby
54 lines
1.2 KiB
Ruby
assert("Enumerator::Lazy") do
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a = [1, 2]
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assert_equal Enumerator::Lazy, a.lazy.class
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end
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assert("Enumerator::Lazy laziness") do
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a = Object.new
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def a.each
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return to_enum :each unless block_given?
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self.b << 10
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yield 1
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self.b << 20
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yield 2
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self.b << 30
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yield 3
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self.b << 40
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yield 4
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self.b << 50
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yield 5
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end
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def a.b(b=nil)
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@b = b if b
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@b
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end
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a.b([])
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assert_equal [1,2], a.each.lazy.take(2).force
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assert_equal [10,20], a.b
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a.b([])
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assert_equal [2,4], a.each.lazy.select{|x|x%2==0}.take(2).force
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assert_equal [10,20,30,40], a.b
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a.b([])
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assert_equal [1], a.each.lazy.take_while{|x|x<2}.take(1).force
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assert_equal [10], a.b
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a.b([])
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assert_equal [1], a.each.lazy.take_while{|x|x<2}.take(4).force
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assert_equal [10,20], a.b
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end
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assert("Enumerator::Lazy#to_enum") do
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lazy_enum = (0..).lazy.to_enum(:each_slice, 2)
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assert_kind_of Enumerator::Lazy, lazy_enum
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assert_equal [0*1, 2*3, 4*5, 6*7], lazy_enum.map { |a| a.first * a.last }.first(4)
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end
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assert("Enumerator::Lazy#zip with cycle") do
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e1 = [1, 2, 3].cycle
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e2 = [:a, :b].cycle
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assert_equal [[1,:a],[2,:b],[3,:a]], e1.lazy.zip(e2).first(3)
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end
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