Lab 5: Working with lists again
Goals: The goals of this lab are to practice writing some operations on lists, and working with lists and loops.
1 Words in a sentence
Goals: To practice representing some data as unions and lists, define operations on it and also to work with interfaces and abstract classes to refactor code.
1.1 Introduction
A sentence in English is made of several words in a particular sequence. You must represent such a sentence as a list of words. Much like the lists we saw in class, this one is made of nodes (represented by a Sentence interface). There is one word per node, called WordNode. The sentence may also contain zero or more punctuation marks, which are represented by a PunctuationNode. The end of the sentence is denoted by a special empty node, called EmptyNode.
Define the following operations for such a list of words:
A method getNumberOfWords that computes and returns the number of words in a sentence. The punctuation does not count as a word.
A method String longestWord that determines and returns the longest word in a sentence. The longest word should not begin or end with punctuation.
A method toString that will convert the sentence into one string. There must be a space between every two words. There is no space between the last word and the end of this sentence. If there is no punctuation mark at the end of the sentence, this string should end with a period (it shouldn’t add the period to the original sentence)
A method Sentence clone() that returns a duplicate of a given sentence. A duplicate is a list that has the same words and punctuation in the same sequence, but is independent of the original list.
A method Sentence merge(Sentence other) that will merge two sentences into a single sentence. The merged list should preserve all the punctuation. The merged list should be returned by this method, and the original lists should be unchanged.
1.2 What to do
Design the interfaces and classes that you need for this purpose.
In a JUnit test class, create examples of sentences and write tests for each operation.
Design the fields and methods for your classes, and verify that your tests pass on them.
Check if you need to abstract any common parts of your design/code.