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Blocks, Closures and Proc Objects
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作者: my4java(http://my4java.itpub.net)
发表于:2006.04.09 22:37
分类: Ruby学习
出处：http://my4java.itpub.net/post/9983/66963
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发表于:2006.04.09 22:37
分类: Ruby学习
出处：http://my4java.itpub.net/post/9983/66963
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Blocks, Closures and Proc Objects
Ruby 的 block 是個不錯的設計. 一個 block 就是一些程式碼, 其 context 為正在動態執行的環境. 有點像是一般稱為 callback 機制, 但 block 方法精巧多了
books = ["Ruby", "Rails"]
books.each do |b|
puts b
end
def three_times
for i in 1..3 do
yield i
end
end
#invoke
three_times do |i|
puts "#{i}, see you!"
end
class File
def self.my_open(*args)
result = f = File.new(*args)
if block_given?
result = yield f
f.close
end
return result
end
end
File.my_open("x.txt", "w") { |f|
f.puts "Hello World!"
}
re: Blocks, Closures and Proc Objects