CS374: Programming Language Principles - Data Structures
The goals of this activity are:
- To explain data types from a record perspective
- To explain data types from a tuple perspective
Consider the activity models and answer the questions provided. First reflect on these questions on your own briefly, before discussing and comparing your thoughts with your group. Appoint one member of your group to discuss your findings with the class, and the rest of the group should help that member prepare their response. Answer each question individually from the activity, and compare with your group to prepare for our whole-class discussion. After class, think about the questions in the reflective prompt and respond to those individually in your notebook. Report out on areas of disagreement or items for which you and your group identified alternative approaches. Write down and report out questions you encountered along the way for group discussion.
Model 1: Generics
- If the language supports coercion or casting, this might not seem useful at first glance. In what circumstances might this be a useful construct?
- Consider the C library function
void qsort(void *base, size_t nitems, size_t size, int (*compar)(const void *, const void*)). How might you sort an array of
int, or an array of
char*, using this same function?
Model 2: Tuple Linked Lists and Data Structures
- What, in an abstract sense, is a linked list (regardless of its implementation in a particular programming language)?
- What is a data structure in Scheme?
Model 3: COBOL Records
- What, in your own words, is a data structure in COBOL?
Model 4: Type Erasure
- Suppose you call
public static max(T a, T b) with two
Integer objects. To what type will T resolve?
- Now suppose you call
public static max(T a, T b) with one
Integer object and one
BigInteger object (where
Integer). To what type will T resolve?
- In Java, how might these resolve if the two objects have nothing in common in their class hierarchy?
- Might this resolution occur at compile time or at runtime? How would this work in each situation?
- Can you think of other examples where type erasure is used commonly in your favorite programming language?
I encourage you to submit your answers to the questions (and ask your own questions!) using the Class Activity Questions discussion board. You may also respond to questions or comments made by others, or ask follow-up questions there. Answer any reflective prompt questions in the Reflective Journal section of your OneNote Classroom personal section. You can find the link to the class notebook on the syllabus.