dict.rb

module Dict
	def Dict.new(num_buckets=256)
		# creats an empty array and then creates 255 empty arrays inside that array
		aDict = []
		(0...num_buckets).each do |i|
			aDict.push([])
		end

		return aDict
	end

	def Dict.hash_key(aDict, key)
		# creates a random number by turning the key string into a number using hash method and diving it by 256
		# the remainder is a number that will be used for index value in the later function
		return key.hash % aDict.length
	end

	def Dict.get_bucket(aDict, key)
		# takes the number above and finds a corresponding bucket by passing it as an index value
		bucket_id = Dict.hash_key(aDict, key)
		return aDict[bucket_id]
	end


	# here is where I am staring having issues, and I can't follow it
	def Dict.get_slot(aDict, key, default=nil)
		# takes whatever is in the corresponding bucket and assigns it to bucket variable (which should be empty at first?)
		bucket = Dict.get_bucket(aDict, key)

		# goes through each element of the bucket array 
		# i dont understand the k, v = kv bit.
		# lets say my key is "Florida", so kv = "Florida".
		# k,v = kv
		# k = "Florida"
		# v = nil
		# where is the value of v coming from??????
		# if key is equal to k then returns index of the key (yep), key itsemf (yep), and value of the key (whaat?? where is it getting it from?)
		bucket.each_with_index do |kv, i|
			k, v = kv
			if key == k
				return i, k, v
			end
		end

		# what is the point of -1 if key is not found? isn't that an element just from the end of the array?
		return -1, key, default
	end

	def Dict.get(aDict, key, default=nil)
		# if I will pretend I understand where v value comes from, this function is easy
		# it just returns the value of the key which is what we are interested in most of the time
		i, k, v = Dict.get_slot(aDict, key, default=default)
		return v
	end

	def Dict.set(aDict, key, value)
		# I have very little idea of what is going on here.
		# I understand what it does, I dont understand HOW
		# it looks up the appropriate bucket for the key-value pair based on the key, and inserts it into the array (or hash?)
		bucket = Dict.get_bucket(aDict, key)
		# I don't quite understand the need for this line
		i, k, v = Dict.get_slot(aDict, key)

		# I can't grasp this 100%
		if i >= 0
			bucket[i] = [key, value]
		else
			bucket.push([key, value])
		end
	end


		# again if I understood where v is coming from, maybe I could understand this.
	def Dict.delete(aDict, key)
		# Deletes the given key from the Dict.
		bucket = Dict.get_bucket(aDict, key)

		(0...bucket.length).each do |i|
			k, v = bucket[i]
			if key == k
				bucket.delete_at(i)
				break
			end
		end
	end


	# again, if I pretend I understand where the script gets v value from, this one is easy
	def Dict.list(aDict)
		# Prints out what's in the Dict.
		aDict.each do |bucket|
			if bucket
				bucket.each {|k, v| puts k, v}
			end
		end
	end
end