зеркало из https://github.com/github/ruby.git
85 строки
1.4 KiB
Ruby
85 строки
1.4 KiB
Ruby
# Linked list example
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class MyElem
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# object initializer called from Class#new
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def initialize(item)
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# @variables are instance variable, no declaration needed
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@data = item
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@succ = nil
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end
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def data
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@data
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end
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def succ
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@succ
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end
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# the method invoked by ``obj.data = val''
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def succ=(new)
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@succ = new
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end
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end
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class MyList
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def initialize
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@head = nil
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end
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def add_to_list(obj)
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elt = MyElem.new(obj)
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if @head
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@tail.succ = elt
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else
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@head = elt
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end
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@tail = elt
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end
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def each
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elt = @head
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while elt
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yield elt
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elt = elt.succ
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end
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end
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# the method to convert object into string.
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# redefining this will affect print.
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def to_s
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str = "<MyList:\n";
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for elt in self
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# short form of ``str = str + elt.data.to_s + "\n"''
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str += elt.data.to_s + "\n"
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end
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str += ">"
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str
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end
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end
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class Point
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def initialize(x, y)
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@x = x; @y = y
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self
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end
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def to_s
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sprintf("%d@%d", @x, @y)
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end
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end
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# global variable name starts with `$'.
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$list1 = MyList.new
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$list1.add_to_list(10)
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$list1.add_to_list(20)
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$list1.add_to_list(Point.new(2, 3))
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$list1.add_to_list(Point.new(4, 5))
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$list2 = MyList.new
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$list2.add_to_list(20)
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$list2.add_to_list(Point.new(4, 5))
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$list2.add_to_list($list1)
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# parenthesises around method arguments can be omitted unless ambiguous.
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print "list1:\n", $list1, "\n"
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print "list2:\n", $list2, "\n"
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