function binary_search, arguments: array, length, value, returns: int
Begin_function
	Set first_index to 0
	Set last_index to length - 1
	While first_index is less than or equal to last_index
	Begin_while
		Calculate middle_index as (last_index + first_index) / 2
		If value is less than array[middle_index]
			Set last_index to middle - 1
		If value is more than array[middle_index]
			Set first_index to middle + 1
		Else
			Return middle_index
	End_while
	Return -1
End_function