34 lines
867 B
Lua
34 lines
867 B
Lua
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-- Ensure that that the element at i is in the right position,
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-- and return a closure which can be used for continuing the sort.
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function quicksorter(i, vec, low, high)
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if low >= high then
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return quicksorter
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else -- low < high
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-- partition the vector and initialize the child closures
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local middle = partition(vec, low, high)
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local left, right = quicksorter
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-- Create the promise
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local function self(i, vec, low, high)
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if i < middle then
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left = left(i, vec, low, middle-1)
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return self
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elseif i > middle then
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right = right(i, vec, middle+1, high)
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return self
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end
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end
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-- Force the promise until i is in the right position
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return self(i, vec, low, high)
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end
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end
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function lazysort(vec, low, high)
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local sorter = quicksorter
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return function(i)
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sorter = sorter(i, vec, low, high)
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return vec[i]
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end
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end
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