2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
|
# File 'lib/array/window.rb', line 2
def window(size, center, even_size_resolution=:prioritize_greater)
return [] if size <= 0
return [self[center]] if size == 1
return self if size >= self.length
closest_limit = ->(size, index) {
return 0 if index < 0
return size - 1 if index >= size
index }
array_closest_limit = closest_limit.curry[self.length]
center = array_closest_limit[center]
lower = array_closest_limit[center - size/2]
upper = array_closest_limit[center + size/2]
while (lower..upper).count < size
lower = array_closest_limit[lower - 1]
upper = array_closest_limit[upper + 1]
end
return self.slice(lower..upper) if (lower..upper).count == size
case even_size_resolution
when :prioritize_greater
return self.slice((lower + 1)..upper)
when :prioritize_lower
return self.slice(lower..(upper - 1))
else
raise ArgumentError, "#{even_size_resolution} is not a known resolution mechanism"
end
end
|