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unless Array.method_defined? :bsearch
class Array
def bsearch
return to_enum(__method__) unless block_given?
from = 0
to = size - 1
satisfied = nil
while from <= to do
midpoint = (from + to).div(2)
result = yield(cur = self[midpoint])
case result
when Numeric
return cur if result == 0
result = result < 0
when true
satisfied = cur
when nil, false
# nothing to do
else
raise TypeError, "wrong argument type #{result.class} (must be numeric, true, false or nil)"
end
if result
to = midpoint - 1
else
from = midpoint + 1
end
end
satisfied
end
end
end
|
