Common Lisp的力量：快速开发环境入门

需积分: 5 165 浏览量更新于2024-07-16 收藏 396KB PDF 举报

"基本的Lisp技术——Basic Lisp Techniques" 在计算机科学领域，Lisp是一种历史悠久且功能强大的编程语言，尤其以其在人工智能和动态编程方面的贡献而闻名。本书《Basic Lisp Techniques》由David J. Cooper, Jr.撰写，旨在向读者展示Common Lisp（Lisp的一个广泛使用的实现）如何优于其他编程语言，并提供一个快速掌握Common Lisp开发环境的指南。 Common Lisp是Lisp家族的一员，它结合了多种Lisp方言的优点，提供了丰富的内置函数、宏系统和动态类型特性，使其成为解决复杂问题的理想选择。这本书通过深入浅出的方式介绍了Lisp的基本技术和应用，帮助读者理解和利用其强大功能。书中可能涵盖了以下核心知识点： 1. **Lisp语法与数据结构**：Lisp以其独特的括号表示法S-表达式（S-expressions）著称，这种简洁的语法使得代码可读性强。Lisp中的数据结构主要包括列表、原子（如数字、符号和字符串）以及高级数据结构如字典和树。 2. **动态类型和动态绑定**：Common Lisp不使用静态类型，变量的类型可以在运行时改变，这允许灵活的编程风格和快速的迭代。 3. **宏系统**：Lisp的宏系统是其独特优势之一，允许程序员创建新的语法构造，扩展语言的语法，实现元编程。 4. **函数式编程**：Lisp鼓励使用函数作为一等公民，这意味着函数可以作为参数传递，也可以作为返回值。这使得编写简洁、可重用的代码变得更加容易。 5. **条件表达式和模式匹配**：Lisp提供了`cond`、`case`等构造来处理条件分支，以及`match`等工具进行模式匹配，增强了代码的可读性和可维护性。 6. **动态扩展性**：Common Lisp支持在运行时修改代码，允许程序自我调整和优化，这在应对不断变化的需求或调试过程中特别有用。 7. **对象系统**：Common Lisp有一个内置的面向对象系统，允许创建类、对象和继承结构，支持多态性。 8. **编译与解释**：Lisp程序可以同时被解释和编译，这为开发过程提供了快速反馈，同时也能够生成高效的机器码。 9. **标准库**：Common Lisp拥有庞大的标准库，包含各种实用的函数和数据结构，覆盖了从数学运算到网络通信的众多领域。 10. **软件开发工具**：Lisp环境通常提供交互式的REPL（Read-Eval-Print Loop），便于测试和调试代码，还有包管理器、自动文档生成等辅助工具。面对日益增长的技术需求和有限的开发者资源，Common Lisp的这些特性使得它能够高效地应对挑战，快速开发出满足用户期望的软件。无论是对于初学者还是经验丰富的开发者，《Basic Lisp Techniques》都是一本宝贵的资源，它将帮助读者掌握Lisp的力量，从而在软件开发的世界中脱颖而出。

8 CHAPTER 2. OPERATING A CL DEVELOPMENT ENVIRONMENT

2.3 Running CL inside a Text Editor

A more powerful way of developing with CL is by running it from within a Unix (or DOS)

shell that is running inside a buﬀer in a powerful text editor, such as Gnu Emacs

. One

advantage of this approach is that the editor (in our example, Emacs) keeps a history of

the entire session: both the expressions the programmer has typed, as well as everything

that CL has printed. All these items can be easily reviewed or recalled.

2.3.1 A Note on Emacs and Text Editors

To develop using Common Lisp, you can, of course, use any text editor of your choice,

although Emacs happens to be espec ially synergistic for working with CL, for reasons we

will discuss later. With a bit of practice, you will ﬁnd that the combination of Emacs and

Allegro CL provides a more powerful and convenient development environment than any of

today’s ﬂashy “visual programming” e nvironments. If you are used to working with the “vi”

editor, Emacs comes with several “vi” emulation modes which you may want to experiment

with on a transitional basis. If you are used to working with a standard Windows-based

text editor, you will ﬁnd a smooth transition to Emacs.

This guide provides examples using Gnu Emacs.

To work with CL in an Emacs shell buﬀer, you should be reasonably familiar with the

text editor. If you are completely new to Gnu Emacs, go through the Emacs Tutorial,

available under the “Help” menu at the top of the Emacs window.

2.3.2 Emacs Terminology

As you will learn in the Emac s Tutorial, when working with Emac s you make frequent use

of key chords. Similar to “chords” on a piano, keychords can allow powerful text processing

with relatively few sequential keystrokes.

They are key combinations involving holding down the Control key and/or the Meta

key, and pressing some other regular key.

See Appendix C for information on which keys represent Control and Meta on your

keyboard, and how you can customize these. To begin, try using the key labeled “Control”

for Control and the keys labeled “Alt” (or the diamond-shaped key on Sun keyboards) for

Meta. If your keyboard has a “Caps Lock” key to the left of the letter “A,” you should

consider remapping this to function as Control, as explained in Appendix C.

This guide uses the following notations to indicate keychords (identical to those refer-

enced in the Emacs Tutorial):

• M-x means to hold down the Meta key, and press (in this case) the “X” key

• C-x means to hold down the Control key, and press (in this case) the “X” key

• C-M-q means to hold down the Control key and the Meta key at the same time , and

press (in this case) the “Q” key

Gnu Emacs comes pre-installed with all Linux systems, and for other systems should come as part

of your Allegro CL distribution. In any case, Emacs distributions and documentation are available from

http://www.gnu.org

10 CHAPTER 2. OPERATING A CL DEVELOPMENT ENVIRONMENT

2.4 Running CL as a subprocess of Emacs

An even more powerful way of developing with Allegro CL is by running it within Emacs

in conjunction with a special Emacs/Lisp interface provided by Franz Inc. This technique

provides all the beneﬁts of running in an Emacs shell as outlined above, but is more powerful

because the Emacs-CL interface extends Emacs with several special commands. These

commands interact with the CL process, making the editor appear to be “Lisp-aware.” The

combination of Emacs with the Emacs-CL interface results in a development environment

whose utility approaches that of the vintage Symbolics Lisp Machines, which many Lisp

aﬁcionados still consider to be technology advanced well beyond anything produced today.

Complete do c umentation of the Emacs-CL interface can be viewed by pointing your

web browser at: file:/usr/local/acl62/doc/eli.htm (you may have to modify this

pathname to point to your actual installed location of Allegro CL (acl62)).

2.4.1 Starting the CL subprocess within Emacs

To enable your Emacs to function in the prop er manner, place the following expressions in

a ﬁle named .emacs in your home directory:

(setq load-path

(cons "/usr/local/acl62/eli" load-path))

(load "fi-site-init")

As above, you may have to modify this pathname to point to your actual installed location

of Allegro CL (acl62). Once you have added these lines to your .emacs ﬁle, you should be

able to restart emacs, then issue the command:

M-x fi:common-lisp

to start CL running and automatically establish a network connection between the Emacs

process and the CL process (in theory, the two processes could be running on diﬀerent

machines, but in practice they usually will run on the same machine). Accept all the

defaults when prompted.

You can also start emacs w ith the CL subprocess automatically from a terminal window,

by invoking emacs with an optional “function” argument, as follows:

emacs -f fi:common-lisp

This will start Emacs, which itself will immediately launch CL.

2.4.2 Working with CL as an Emacs subprocess

Once you have s tarted CL within Emacs, you will be presented with a special buﬀer named

*common-lisp* which in many ways is similar to simply running CL within a shell within

Emacs as above. But now you have several more capabilities available to you, as outlined

in Table 2.1.

To summarize, the Lisp-Emacs interface adds capabilities such as the following to your

development environment:

2.4. RUNNING CL AS A SUBPROCESS OF EMACS 11

Keychord Action Emacs-Lisp function

C-M-x Compiles and loads

the function near the

Emacs point

fi:lisp-eval-or-compile-defun

C-c C-b Compiles and loads

the current Emacs

buﬀer

fi:lisp-eval-or-compile-current-buffer

M-A Shows the Argument

List for a CL function

fi:lisp-arglist

C-c . Finds the deﬁnition

of a CL object

fi:lisp-find-definition

Table 2.1: Common Commands of the Emacs-Lisp Interface

• Start and stop the C L process using Emacs commands

• Compile and load ﬁles into the running CL process, directly from the open Emacs

buﬀer you are editing (no need explicitly to save the ﬁle, call the compile-file

function, then call the load function, as with the “in-a-shell” techniques above)

• Query the running CL process for information about objects currently deﬁned in it

— for example, querying the CL, directly from Emacs, for the argument List of a

particular function

• Run multiple read-eval-print loops, or listeners, in diﬀerent threads of CL execution,

as Emacs buﬀers

• Compile and load speciﬁed sections of an open Emacs buﬀer

• Locate the source code ﬁle corresponding to any deﬁned CL object, such as a function

or parameter, and automatically open it in an Emacs buﬀer

• Perform various debugging actions and other general CL help capabilities, directly

from within the Emacs session

In short, Emacs becomes a remarkably powerful, inﬁnitely customizable, CL integrated

development environment.

2.4.3 Compiling and Loading a File from an Emacs buﬀer

Try it: Try starting Emacs with a CL subprocess as outlined above. I f you have trouble,

consult the URL listed above for complete instructions on running the Lisp-Emacs interface.

Once you have Emacs running with a CL subprocess, you should have a buﬀer named

*common-lisp*. If your Emacs session is not already visiting this buﬀer, visit it with the

command C-x b *common-lisp*, or select *common-lisp* from the “Buﬀers” menu in

Emacs (see Appendix C for instructions on how to set up a “hot key” for this and other

common tasks when working with the Emacs-Lisp interface).

12 CHAPTER 2. OPERATING A CL DEVELOPMENT ENVIRONMENT

Now, split your Emacs frame into two windows, with the command C-x 2. In both

windows you s hould now see *common-lisp*. Now move the point

to the other window

with C-x o, and open the hello.lisp ﬁle you created for the previous exercise

. If you

don’t have that ﬁle handy, create it now, with the following contents:

(defun hello ()

(write-string "Hello, World!"))

Now, compile and load the contents of this function deﬁnition with C-M-x. Finally, switch

to the *common-lisp* window again with C-x o, and try invoking the hello function by

calling it in normal Lisp fashion:

CL-USER(5): (hello)

Hello, World!

"Hello, World!"

You should see the results printed into the same *common-lisp* buﬀer.

Try it: Now try the following: go back to the hello.lisp buﬀer, make an edit to

the contents (for example, change the String to "Hello, CL World!"). Now compile the

buﬀer with this change (Note that you do not necessarily have to save the ﬁle). Finally,

return to the *common-lisp* buﬀer, and try invoking the function again to conﬁrm that

the redeﬁnition has taken eﬀect.

You have now learned the basic essentials for working with the Emacs-Lisp interface.

See Appendix C for more information about Emacs customization and convenient Emacs

commands speciﬁc to the Lisp editing mode.

2.5 Integrated Development Environment

Some CL implementations support or integrate with an IDE, or Integrated Development

Environment. Such environments provide visual layout and design capabilities for User

Interfaces and other graphical, visual techniques for application development. For example,

such a system is available for Allegro CL on the Microsoft platforms. The details of these

systems are covered in their own documentation and are beyond the scope of this guide.

2.6 The User Init F ile

When CL begins execution, it usually looks for an initialization ﬁle, or “init” ﬁle, to load.

When CL loads this ﬁle, it will read and evaluate all the commands contained in it.

The default name and loc ation for this initialization ﬁle is

.clinit.cl

In technical Emacs parlance, the point is the insertion point for text, and the cursor is the mouse

pointer.

Remember that pressing the space bar will automatically complete ﬁlenames for you when opening ﬁles

in Emacs.

剩余99页未读，继续阅读

weixin_38743737

粉丝: 376
资源: 2万+

Common Lisp的力量：快速开发环境入门

关于Lisp，常见LISP的高级技术On Lisp, Advanced Techniques for Common LISP

Basic Lisp Techniques

介绍Autocad二次开发的技术路线，包括Autolisp、VBA、.NET等技术的特点和应用场景，以及如何选择合适的技术路线进行开

《autocad完全应用指南 autolisp+dcl+visual lisp程序设计篇

autolisp入门基础教程

visuallisp函数手册

autolisp.chm

lisp函数参考手册

autolisp官方开发者文档

fas反编译成lisp

最新资源