Snobol4【1】 语言实战：开发文本提取【2】与解析工具集【3】
Snobol4 是一种古老的编程语言，最初由 Calvin Mooers 在1962年设计，主要用于文本处理【4】。尽管它在现代编程语言中并不常见，但它在文本处理领域仍然有其独特的应用价值。本文将围绕 Snobol4 语言，实战开发一个文本提取与解析工具集，以展示其在文本处理方面的能力。
Snobol4 简介
Snobol4 是 Snobol 系列语言的第四个版本，它继承了 Snobol3 的语法【5】和功能，并增加了一些新的特性。Snobol4 的主要特点包括：
- 强大的文本处理能力
- 简洁的语法
- 高效的运行速度【6】
Snobol4 的语法类似于英语，这使得它易于学习和使用。以下是一个简单的 Snobol4 程序示例【7】，用于打印出输入文本中的所有单词【8】：
```snobol
:input
|' ' |
|'.' |
|'!' |
|'?' |
|'(' |
|')' |
|'[' |
|']' |
|'{' |
|'}' |
|'/' |
|'' |
|'+' |
|'-' |
|'=' |
|'>' |
|'<' |
|'&' |
|'|' |
|'^' |
|'%' |
|'"' |
|'`' |
|';' |
|',' |
|'_' |
|'0'-'9' |
|'a'-'z' |
|'A'-'Z' |
|
[print]
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[print ' ']
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[print '']
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[print ' ']
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