Snobol4 语言 模式匹配应用实战 HTML 标签提取

Snobol4 语言模式匹配应用实战：HTML 标签提取

Snobol4 是一种古老的编程语言，以其强大的字符串处理能力而闻名。尽管在现代编程中并不常见，但它在文本处理和模式匹配方面仍然有其独特的应用价值。本文将探讨如何使用 Snobol4 语言进行 HTML 标签的提取，这是一种典型的模式匹配应用。

Snobol4 简介

Snobol4 是一种高级编程语言，由 Stephen C. Johnson 在 1962 年设计。它特别适合于文本处理和模式匹配任务。Snobol4 的语法简洁，易于理解，并且具有丰富的字符串操作功能。

HTML 标签提取的挑战

HTML 标签提取是一个常见的文本处理任务，其目的是从 HTML 文档中提取出所有的标签。HTML 标签通常由尖括号包围，如 `` 和 ``。提取这些标签需要识别并处理标签的开始和结束。

Snobol4 模式匹配

Snobol4 提供了强大的模式匹配功能，可以通过定义模式来匹配字符串。以下是一些 Snobol4 中常用的模式匹配操作符：

- `@`：匹配任意字符
- ``：匹配零个或多个前面的字符
- `+`：匹配一个或多个前面的字符
- `?`：匹配零个或一个前面的字符

HTML 标签提取的 Snobol4 实现

以下是一个使用 Snobol4 提取 HTML 标签的示例代码：

```snobol
:html [in] [out]
[in] @
[out] @
[in] @
[out] @
[in] @
[out] @
[in] @
[out] @
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