Chapter 1.7 --- Extra Credit

Arrays and Vectors

"As with any tool, merit or demerit lies in how it is used."

When you need to squeeze extra efficiency out of your Lisp program, usually the first place to turn after minimizing consing-operations is to migrate your list data structures to arrays and vectors. You will lose the flexibility of lists, but you do gain in performance and reduce memory usage.

Just like Lists, Arrays descend from the Sequence type, and vectors are a special type of array with only one dimension, so all sequence operations will also work on arrays and vectors. List operations, however, will not. Luckily, Common Lisp includes a number of utilities for working with arrays and vectors---and you should get to know them immediately so that you can start improving your codebase right away.

This chapter will contain exercises on:

• Sequences, Arrays, and Vectors
• Making Arrays
• Element-Types of Arrays
• Fixed-Size Arrays
• Extensible Arrays
• Fill-Pointers
• Splicing Arrays
• Splitting Arrays
• Concatenating Arrays
• Matrices
• Matrix Multiplication
• Octet Vectors
• Octet Vectors and Streams

Exercise 1.7.1

Sequences Revisited: Arrays and Vectors

Exercise 1.7.2

Arrays

Exercise 1.7.3

More Arrays: Element-Type

Exercise 1.7.4

More Arrays: Dimension

Exercise 1.7.5

More Arrays: Extensible

Exercise 1.7.6

More Arrays: Fill-Pointers

Exercise 1.7.7

Splicing Arrays

Exercise 1.7.8

Splitting Arrays

Exercise 1.7.9

Concatenating Arrays

Exercise 1.7.10

Matrices

Exercise 1.7.11

Matrix Multiplication

Exercise 1.7.12

Octet-Vectors

Exercise 1.7.13

More Octet-Vectors

Exercise 1.7.14

Vectors and Binary Streams