The Pretty Printer Backend The Pretty Printer Backend You can start by defining a class with two slots—one to hold an instance of indenting-printer and one to hold the tab wid...

FOO Special Operators FOO Special Operators You could stop there; certainly the FOO language is expressive enough to generate nearly any HTML you’d care to. However, you can ad...

6. Variables Copyright © 2003-2005, Peter Seibel 6. Variables The next basic building block we need to look at are variables. Common Lisp supports two kinds of variables: l...

Character Escaping Character Escaping The first bit of the foundation you’ll need to lay is the code that knows how to escape characters with a special meaning in HTML. There a...

11.9 封装 (Encapsulation) 11.9 封装 (Encapsulation) 面向对象的语言通常会提供某些手段，来区别对象的表示法以及它们给外在世界存取的介面。隐藏实现细节带来两个优点：你可以改变实现方式，而不影响对象对外的样子，而你可以保护对象在可能的危险方面被改动。隐藏细节有时候被称为封装 (encapsulated)。 虽然...

Other Special Operators Other Special Operators The four remaining special operators, **LOCALLY** , **THE** , **LOAD-TIME-VALUE** , and **PROGV** , all allow you to get at part...

Chapter 9 练习 (Exercises) Chapter 9 练习 (Exercises) 定义一个函数，接受一个实数列表，若且唯若 (iff)它们是非递减 (nondecreasing)顺序时返回真。 定义一个函数，接受一个整数 cents 并返回四个值，将数字用 25- , 10- , 5- , 1- 来显示，使用最少数量的硬...

3.8 树 (Trees) 3.8 树 (Trees) Cons 对象可以想成是二叉树， car 代表左子树，而 cdr 代表右子树。举例来说，列表 (a (b c) d) 也是一棵由图 3.8 所代表的树。 （如果你逆时针旋转 45 度，你会发现跟图 3.3 一模一样） 图 3.8 二叉树 (Binary Tree) Common ...

13.6 快速操作符 (Fast Operators) 13.6 快速操作符 (Fast Operators) 本章一开始就宣称 Lisp 是两种不同的语言。就某种意义来讲这确实是正确的。如果你仔细看过 Common Lisp 的设计，你会发现某些特性主要是为了速度，而另外一些主要为了便捷性。 例如，你可以通过三个不同的函数取得向量给定位置上的元素...

The Heart of a Spam Filter The Heart of a Spam Filter In this chapter, you’ll implement the core of a spam-filtering engine. You won’t write a soup-to-nuts spam-filtering appli...