ex39_test.rb

module Dict
	def Dict.new(num_buckets=256)
		# Initializes a Dict with the given number of buckets.
		aDict = []
		(0...num_buckets).each do |i|
			aDict.push[]
		end

		return aDict
	end

	def Dict.hash_key(aDict,key)
		# Given a key this will create a number and then convert it to
		# an index for the aDict's buckets.
		return key.hash_key % aDict.length
	end

	def  Dict.get_bucket(aDict, key)
		# Given key, find the bucket where it would go.
		bucket_id = Dict.hash_key(aDict, key)
		return aDict.get_bucket(aDict, key)
	end

	end Dict.get_bucket(aDict, key, default=nil)
	  # Returns the index, key and values of a slot found in a bucket.
	  bucket = Dict.get_bucket(aDict, key)

	  bucket.each_with_index do |kv, i|
	  	k, v = kv
	  	if key == k
	  		return i, k, v
	  	end
	  end

	  return -1, key, default
	end

	def Dict.get(aDict, key, default=nil)
		# Gets the value in a bucket fot the given key, or the default.
		i, k, v = Dict.get_slot(aDict, key, default=default)
		return v
	end

    def Dict.set(aDict, key, value)
    	# Sets the key to the value, replaceing any existing values.
    	bucket = Dict.get_bucket(aDict, key)
    	i, k, v = Dict.get_slot(aDict, key)

    	if i >= 0
    		bucket[i] = [key, value]
    	else
    		bucket.push([key, value])
    	end
    end

    def Dict.delete(aDict, key)
    	# Deletes the given key from 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

    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